Research ArticlePermeability Properties of Crushed Stone Aggregates in BeddingCourse of Urban Permeable Roads An Experimental Study

Rongrong Mao and Haiyan Yang

Jiangsu Shipping College Nantong Jiangsu 226010 China

Correspondence should be addressed to Rongrong Mao maorongrong8126com

Received 21 August 2020 Revised 10 October 2020 Accepted 19 October 2020 Published 31 October 2020

Academic Editor Hualei Zhang

Copyright copy 2020 Rongrong Mao and Haiyan Yang (is is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in anymedium provided the original work isproperly cited

Crushed stone is the most common material for use in the aggregate of bedding course (e aggregate for the bedding course ofpermeable roads needs to not only meet the requirements of basic mechanical properties but also ensure permeability andstructural stability (is work analyzed permeability under extreme rainfall conditions and the particle mass loss during per-meation and then investigated the stability of crushed stone aggregate and examined the optimal gradation and compaction levelsof the crushed stone aggregate in engineering applications It shows that (1) the permeation process included two phases and thechange of permeation velocity mainly occurred in the first phase (e permeation velocity of samples with different gradations atdifferent compaction levels showed a stepwise change in its order of magnitude (2)(e change in permeability coincided with thechange in flowrate most probably because the sudden change of the flow altered the permeability of the sample Factors such asgradation compaction and the randomness of particles arrangement in the crushed stone during sample charging all affected thepermeability of the sample (3) During the permeation process the mass loss decreased with rising gradation (e gradation andcompaction had strong influence on particle mass loss (erefore ensuring the structural stability of permeable road necessitatescareful selection of the gradation and compaction for the crushed stone aggregate It is recommended to use the crushed stonesample with a gradation of n 07 and a compaction level of no greater than 20mm for the aggregate of the bedding course

1 Introduction

Presently most roads in Chinese cities use imperviouspavement (e drawbacks of impervious pavement includethe following (1) It disrupts the natural circulation of waterand prevents precipitation from replenishing groundwaterbecause it lacks the permeability of soil and vegetation (2) Itobstructs the heat and water exchange between the air andthe ground and worsens the ldquoheat islandrdquo effect in urbanareas because it releases massive amount of absorbed solarheat (3) It tends to cause accumulation of water andeventually leads to urban flooding [1ndash3] To address theseproblems Germany took the lead in 1960 by constructingporous asphalt pavements Since the 1980s imperviouspavement is increasingly replaced around the globe bypermeable asphalt permeable tile cobble stone-like pave-ment etc to improve the permeability so that rainwater can

rapidly infiltrate into soil to reduce soil erosion conservewater sources and improve regional ecological environ-ments [3ndash5]

Extensive works have been carried out on the pavementand the bedding course of permeable roads Watanabe S [1]studied the runoff control of permeable pavement at an areain Yokohama Japan Schluter and Jeffries [2] studied howthe porosity of the filling in the permeable pavement couldaffect the water flow at the exit of parking lot and help reducepeak runoff Benedetto [3] used permeable pavement topromote infiltration and mitigate the accumulation of watercaused by rainfall at an airport From a field study on thelong-term permeability of the permeable concrete pavementand brick pavement Borgwardt and Chen [4] found that thepermeability of these pavements decreased by several ordersof magnitude after several years of use and the size of thefiller particles determined the permeability Beeldens et al

HindawiAdvances in Civil EngineeringVolume 2020 Article ID 8867375 9 pageshttpsdoiorg10115520208867375

[5] gave an overview of various permeable roads in Belgiumfrom the monitoring data of newly completed projects ofpermeable pavement in Belgium and the test data of per-meable pavement after nearly 15 years of use (e mea-surement data showed that these roads had goodperformance and long-lasting permeability (ey comparedand analyzed the permeability data investigated how the useof permeable roads would impact urban sustainabledrainage management and discussed promoting the ap-plication of permeable roads through legislation Wang et al[6] proposed the use of permeable pavement to allowrainwater to infiltrate soil conserve groundwater andregulate urban ecological environment Wang et al [7 8]examined the relationship between urban permeablepavement and urban ecology Wu et al [9] used a home-made simulated rainfall system to experimentally studytypical bedding materials such as impervious tiles cementfloors permeable tiles and grass Ding et al [10] studied theoptimal mix ratio and production technology of materialsfor permeable roads through extensive experiments on therawmaterials and manufacturing processes Zhang [11] usedin-situ permeameter single-ring permeameter double-ringpermeameter and other instruments to test the permeationof permeable recyclable pellets under constant and variablehydraulic head to compare the applicability of different testmethods of permeability coefficient Zhang et al [12] foundthat the permeability of concrete permeable bricks decreasedwith their service life In the first two years the permeablebricks generally showed good permeable effect but theirpermeable property weakened significantly after two yearsHou et al [13 14] studied permeable brick pavements withdifferent bedding course structures and found that the use ofpermeable brick pavement could significantly reduce surfacerunoff (e surface runoff coefficient was always lower whenpermeable brick was used instead of impervious brick andthe infiltration depended on the bedding course structure ofthe permeable brick Meng et al [15] examined represen-tative permeable roads in Shanghai to survey the actualpermeability summarize the current application of per-meable roads and analyze the key factors of permeabilityRelated works [12ndash16] show that the bedding course ofpermeable road directly affects the permeability and it isthus essential to study the permeability of the beddingcourse

Crushed stone is the most common material for use inthe aggregate of bedding course Because of extreme rainfall[17 18] and continuous rain erosion the migration and lossof particulate matter in the aggregate of bedding course willtake place and undermine the structural stability of thebedding course

In this work we considered the use of crushed stone asthe aggregate in the bedding course of urban permeableroads examined the permeability of crushed stone as well asthe loss of particulate matter under rain erosion and in-vestigated the choice of gradation and compaction of bed-ding course aggregate Specifically we used a continuousgrading mixture to simulate the bedding course and testedthe infiltration speed the permeability of the mixture andthe material migration in the permeation experiments We

then analyzed the impact of gradation and compaction onthe permeability and mass loss of particulate matter in thebedding course

2 Materials and Methods

21 Sample Preparation (e bedding course of roads iscommonly laid using crushed stone of different particle sizesbecause the gaps between larger particles can be filled bysmaller particles However the filling particles should besmaller than the gap distance so as to avoid the interferencebetween large and small particles (erefore particles ofdifferent sizes should be mixed based on a certain ratio [19]In the current test crushed stone was sieved into five dif-ferent sizes ie 0ndash5mm 5ndash10mm 10ndash15mm 15ndash20mmand 20ndash25mm and Talbot continuous grading [20] wasadopted

p(d) di

dM

1113888 1113889

n

times 100 (1)

where p(d) is the percentage of particles whose size is nolarger than di and dM is the maximum particle size(emassof particles of each size is

Mdi+1di

di+1

dM

1113888 1113889

n

minusdi

dM

1113888 1113889

n

1113890 1113891 times MT (2)

whereMT is the total mass of the sample and di and di+1 areadjacent particle sizes

Wang et al showed that when the Talbot power index nis 01 and 02 the content of fine particles is relatively highwhich is likely to cause instability [21 22] (erefore thecurrent test considered n values of 04 05 06 and 07 (emass of each sample is 2 kg in the test and the mass ofparticles of different sizes is given in Table 1 Four differentcompaction levels (10mm 20mm 30mm and 40mm) wereevaluated to analyze the impact of compaction level onparticle loss and permeability over time

22 Permeability Test System Figure 1 illustrates the home-made permeability test system [23] for broken rock withvariable mass which was adopted in this work to test thepermeability of crushed stone aggregate (e system consistsof an axial load and displacement control module a per-meation module and a data acquisition and analysismodule A particle recovery module is added to measuremass loss

(e axial load and displacement control module includesa material testing machine a single acting hydraulic cyl-inder a variable displacement piston pump etc (e single-action hydraulic cylinder has the maximum traverse of50mm the variable displacement piston pump has the ratedpressure of 315MPa and the permissions error of plusmn4

(e permeation module includes a permeameterpipelines a fixed displacement piston pump a double-actinghydraulic cylinder etc (e quantitative displacement pistonpump can provide amaximum pressure about 8MPa and itswork pressure is 7MPa maximum displacement is about

2 Advances in Civil Engineering

600 L per hour(e double-action hydraulic cylinder with aninner diameter of 220mm has a piston with a diameter of160mm and its maximum traverse and volume are 500mmand 20 L respectively

(e data acquisition and analysis module includes dis-placement sensors flow sensors pressure sensors datacollectors PC etc (e particle recovery module includesvibrating sieves filter cloths an oven an electronic scale etc(e filter screen is the 300 meshes fine gauze and thecorresponding collected grains size could reach 48 microns(e pressure transducer has the measure traverse andmeasure accuracy of 16MPa and 2 kPa respectively

23 Test Procedure Figure 2 shows the test process (esamplersquos initial height was measured after the sample wascharged Because manual charging gave highly variableporosity after being packed into the permeameter sampleswere firstly subjected to 002MPa at 1mmmin for pre-liminary compression without crushing the particles (e

samplersquos actual height was then measured at this point basedon the displacement of the testing machine Water was theninjected to saturate the sample and start the permeation test(e pressure and flow data were recorded in real-timeduring the test (e lost particles were collected at definedintervals because they could not be measured in real-time(e mass loss of particles was relatively high at the start ofthe test and the interval for particle collection was initially setto 2min (e collection interval could then be graduallyincreased as the mass loss decreased over time

3 Results and Analysis

From the permeability test of the crushed stone aggregatedata such as water pressure flowrate and particle mass lossduring permeation in the sample were measured and thechange of physical quantities such as permeation velocitypermeability and particle loss were calculated andrationalized

31 Variation of Permeation Velocity During the test theflowrate Q was measured in real-time from which thepermeation velocity v could be calculated as follows

v Q

πa2 (3)

where a is the inner radius of the permeameter (a 50mm)(e permeation velocity was calculated from the real-

time flow in the test Figure 3 shows that the permeationprocess includes two phases corresponding to fast mass lossand slow permeation respectively and the change in per-meation velocity mainly occurred in the slow permeationphase During fast mass loss the permeation velocity in-creased because of rising porosity that resulted from themigration and loss of small particles Figure 3 shows that theduration of the mass loss stage varied for different samples

Table 1(e mass qualities of different diameters broken rock withdifferent Talbot power exponents

Mass (g) n04 05 06 07

Rock particle sizes

0ndash5mm 10506 8944 7615 64835ndash10mm 3357 3705 3927 404810ndash15mm 2441 2843 3179 345615ndash20mm 1988 2397 2773 312020ndash25mm 1708 2111 2506 2892

Particle recovery module

Axial load and displacement control module

Permeation moduleData acquisition and analysis module

Figure 1(e home-made permeability test system for broken rockwith variable mass

System debugging

Mixing and charging

Initial axial loading to 002MPa

Saturating

Seepage

Discharging

Analyzing data

Testing the system operation

Measuring the initial height

Measuring the actual height

Collecting lost fine particlesat regular intervals

Acquiring pore pressure andflow in real time

Figure 2 (e test process

Advances in Civil Engineering 3

because their contents of small particles that could migratewere different(e content of small particles was the smallestfor the n 07 sample whose mass loss phase lasted for onlyas short as 50 s In contrast the n 04 and n 05 sampleshad a relatively longer mass loss phase because they had ahigher content of small particles Particularly for the n 05sample with initial compaction of 20mm the mass lossphase lasted for nearly 930 s

Table 2 also shows a stepwise increase in the order ofmagnitude of the permeation velocity for samples with differentgradations at different levels of compaction For the n 04 andn 05 samples the permeation velocity always increased fromthe order of 10minus3ms to the order of 10minus2ms regardless ofcompaction level For the n 06 samples the permeationvelocity remained at the 10minus2ms level throughout the test whenthe initial compaction was 10mm but showed a lower initialpermeation velocity at the 10minus3ms level with higher initialcompactions For the n 07 samples the initial permeationvelocity was at the 10minus2ms level when the initial compactionswere 10minus30mm but decreased to the 10minus3ms level when theinitial compaction increased to 40mm (erefore the initialcompaction level had a significant impact on the permeationvelocity and affected the permeation velocity at the beginning ofthe test

32Variationof Permeability Lu et al [24 25] used a home-made permeameter to analyze the flow characteristics of

permeable pavement mixtures under different hydraulicgradients (e results show that Darcyrsquos law is not applicableto analyzing directional water transport in permeablepavement materials With rising hydraulic gradient theReynolds number of permeable pavement materials in-creases and the water flow in permeable pavement materialstransitions from Darcy flow to non-Darcy flow

(e Forchheimer equation was used to describe the non-Darcy flow of the permeation process for the aggregate inthis paper

minusnablap μk

v + ρβv2 (4)

where nablap is the pressure gradient μ is the dynamic viscosityof the fluid k is the permeability ρ is the fluid density and βis the non-Darcy factor

(e permeability k and non-Darcy factor β in Equation(4) are the two key parameters that describe the permeabilitycharacteristics of crushed stone and they can be calculated

000E + 00

500E ndash 03

100E ndash 02

150E ndash 02

200E ndash 02

250E ndash 02v (

ms

)

t (s)

1020

3040

0 200 400 600 800 1000

(a)

000E + 00

500E ndash 03

100E ndash 02

150E ndash 02

200E ndash 02

250E ndash 02

v (m

s)

t (s)

1020

3040

0 200 400 600 800 1000

(b)

000E + 00

500E ndash 03

100E ndash 02

150E ndash 02

200E ndash 02

250E ndash 02

v (m

s)

t (s)

1020

3040

0 200 400 600 800 1000

(c)

000E + 00

500E ndash 03

100E ndash 02

150E ndash 02

200E ndash 02

250E ndash 02

v (m

s)

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 3 (e permeation velocity of the mass loss stage varied for different samples (a) n 04 (b) n 05 (c) n 06 (d) n 07

Table 2 (e change of magnitudes of permeation velocity in thewhole test

10mm 20mm 30mm 40mm04 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2

05 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2

06 10minus2sim10minus2 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2

07 10minus2sim10minus2 10minus2sim10minus2 10minus2sim10minus2 10minus3sim10minus2

4 Advances in Civil Engineering

from the time series of the permeation velocity and thepressure gradient collected in the test [26]

k μ 1113936

ni1 v3i( 1113857

2minus 1113936

ni1 v

2i 1113936

ni1 v

4i1113960 1113961

1113936ni1 Δpiv

2i 1113936

ni1 v

3i minus 1113936

ni1 Δpivi 1113936

ni1 v

4i

β 1113936

ni1 Δpivi 1113936

ni1 v

3i minus 1113936

ni1 Δpiv

2i 1113936

ni1 v

2i

ρ 1113936ni1 v3i( 1113857

2minus 1113936

ni1 v

2i 1113936

ni1 v

4i1113960 1113961

(5)

Figure 4 shows how the permeability of samples withdifferent gradation under different compaction levels variedwith time(e permeability of all samples was at the order of10minus11ndash10minus10m2 during the entire permeation process (epermeability of all samples showed a sharp increase in therapid mass loss phase and the increase was concomitantwith the sudden change of flowrate It can be speculated thatthe sudden change of the flow led to the change of thesamplesrsquo permeability In the later part of the permeationtest the permeability only demonstrated minor vacillationand remained basically unchanged In addition gradationand compaction levels also affected the permeability of thesamples For example as seen in Figure 4 the n 05 samplehad the highest permeability of 27times10minus10m2 while then 07 sample only had a permeability no greater than44times10minus11m2 (e influence of compaction on permeabilityseemed to be somewhat irregular possibly due to the

randomness of particle arrangement when the samples werecharged into the device

(e permeability of the aggregate needs to be consideredin selecting aggregates for the bedding course of the per-meable road Ideally aggregates with relatively high per-meability should be chosen

Figure 5 shows the non-Darcy factors for differentsamples varied with time (e logarithmic form was used inthe figure because the non-Darcy factors varied acrossseveral orders of magnitude Contrary to permeability thenon-Darcy factors gradually decreased as time elapsed [27]

It is worth noting that the change in the permeability ofthe crushed stone aggregate during the permeation processwas related to the particle loss during the test

33 Particle Mass Loss During the permeation processsmall particles of crushed stone were carried by the waterflow and left the permeameter [28ndash31] (e lost particleswere collected at given time intervals at ∆ti (i 1 2 3 ) asshown in Figure 6 and their mass after drying was weighedand recorded asmi (i 1 2 3 ) In this way the total massloss 1113936 mi during the permeation process could be calculatedIt can be seen from Figure 6 that the size of the lost particlesranged mostly in 0ndash2mm and the amount of collectedparticles gradually decreased as time elapsed

Figure 7 shows the mass loss of crushed stone aggregateswith different gradations It could be found that as the

000E + 00

400E ndash 11

800E ndash 11

120E ndash 10

160E ndash 10

200E ndash 10k

(m2 )

t (s)

1020

3040

0 200 400 600 800 1000

(a)

000E + 00

100E ndash 10

500E ndash 11

150E ndash 10

200E ndash 10

250E ndash 10

300E ndash 10

k (m

2 )

t (s)

1020

3040

0 200 400 600 800 1000

(b)

000E + 00

200E ndash 11

400E ndash 11

600E ndash 11

800E ndash 11

100E ndash 10

k (m

2 )

t (s)

1020

3040

0 200 400 600 800 1000

(c)

000E + 00

100E ndash 11

200E ndash 11

300E ndash 11

400E ndash 11

500E ndash 11

k (m

2 )

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 4(e permeability of samples with different gradation under different compaction levels varied with time (a) n 04 (b) n 05 (c)n 06 (d) n 07

Advances in Civil Engineering 5

gradation increased the content of fine particles decreasedAlthough some secondary small particles were producedduring the permeation process from water-rock interactionthe mass loss still mainly came from the original smallparticles (erefore the mass loss decreased with risinggradation (e n 04 sample had the highest mass loss ofabout 280 g while the n 07 sample had a maximum massloss of 48 g which was only 17 that of the n 04 sample

For samples with the same gradation the mass lossincreased with intensifying compaction For example themass loss of the n 06 sample under 40mm compaction was452 of its mass loss under 10mm compaction In contrastthe mass loss of the n 05 sample under 40mm compactionwas 175 of its mass loss under 10mm compaction (edifference in these increments was related to factors such asgradation and the particle arrangement during samplecharging It could be seen that gradation and compactionhave significant impact on the mass loss In selecting theaggregate of the bedding course for permeable roads it is

crucial to determine the gradation and the correspondingcompaction to ensure structural stability

Figure 7 also shows that the rate of mass loss differedbetween samples For example for samples with the samecompaction level of 10mm themass loss rate decreased withrising gradation (e maximum mass loss rate of the n 04and n 07 samples reached 83 gs and 005 gs respectively(e former was 166 times the latter (e mass loss rate ofsamples with the same gradation but different compactionalso varied significantly For example the maximum massloss rate of the n 05 sample with 30mm and 20mmcompaction reached 586 gs and 0054 gs respectivelywhich were two orders of magnitude apart

4 Discussion

(e permeability mass loss and mass loss rate of all sampleswere classified based on the relevant specifications of per-meable roads with the standard being 20times10minus11m2 100 g

0

5

10

15

20

25

30ln

(β)(

mndash1

)

t (s)

1020

3040

0 200 400 600 800 1000

(a)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(b)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(c)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 5 (e non-Darcy factor of samples with different gradation under different compaction levels varied with time (a) n 04 (b)n 05 (c) n 06 (d) n 07

m1m2 m3 m4 m5

Figure 6 (e lost particles collected at given time intervals

6 Advances in Civil Engineering

and 05 gs respectively Accordingly the tested samples andcompactions were categorized into three sets recommended(R) not recommended (N) and uncertain (U) (e optimalgradation and compaction levels were then derivedstatistically

It can be found from Table 3 that the permeability ofmost samples satisfied the requirements as an aggregate forpermeable road but samples with smaller gradation had a

higher mass loss during permeation which may affect thestructural stability of the bedding course For samples with amass loss less than 5 structural instability could also occurif the mass loss rate was too high (us the overall rec-ommendation was to use crushed stone with a gradation ofn 07 and adopt a compaction level of no more than 20mmin choosing crushed stone as the aggregate for the beddingcourse of permeable roads It should be noted that adhesives

0

50

100

150

200

250

300summ

i (g)

t (s)

1020

3040

0 200 400 600 800 1000

(a)

0

50

100

150

200

250

300

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(b)

0

50

100

150

200

250

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(c)

0

10

20

30

40

50

60

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 7 (e mass loss of crushed stone aggregates with different gradation (a) n 04 (b) n 05 (c) n 06 (d) n 07

Table 3 (e optimal gradation and compaction levels

Gradation andinitial compression Permeability Mass loss (e mass loss rate

04

10 R R N20 R N N30 R N N40 R N R

05

10 R N N20 U N R30 R N N40 R N N

06

10 N R R20 R N N30 R N N40 R N N

07

10 R R R20 R R R30 N U R40 N U R

Advances in Civil Engineering 7

were not used in this study (e use of adhesives will changethe permeability and particle loss of the bedding course

5 Conclusions

(e aggregate for the bedding course of permeable roadsneeds to not only meet the requirements of basic mechanicalproperties such as compressive strength and shear strengthbut also ensure permeability and structural stability (iswork analyzed permeability under extreme rainfall condi-tions and the particle mass loss during permeation and theninvestigated the stability of crushed stone aggregate andexamined the optimal gradation and compaction of thecrushed stone aggregate in engineering applications (emain conclusions are as follows

(1) (e permeation process included two phases thefirst being rapid mass loss and the second being slowpermeation (e change of permeation velocitymainly occurred in the first phase (e duration ofthe rapid mass loss phase varied for samples withdifferent gradations because of their differingamount of small particles that could migrate (epermeation velocity of samples with different gra-dations at different compaction levels showed astepwise change in its order of magnitude

(2) (roughout the permeation process the perme-ability of samples with various gradations was all atthe order of 10minus11ndash10minus10m2 (e change in perme-ability coincided with the change in flowrate mostprobably because of the sudden change of the flowaltered the permeability of the sample Factors suchas gradation compaction and the randomness ofparticles arrangement in the crushed stone duringsample charging all affected the permeability of thesample

(3) During the permeation process the mass loss de-creased with rising gradation (e mass loss of thesamples with the same gradation generally increasedwith intensifying compaction It could be seen thatgradation and compaction had strong influence onparticle mass loss (erefore ensuring the structuralstability of permeable road necessitates careful se-lection of the gradation and compaction for thecrushed stone aggregate

(4) (e permeability of most samples could satisfy therequirements as the aggregate but structural stabilityof the bedding course of the permeable road may beat stake if the sample had a high mass loss or massloss rate during permeation It is recommended touse the crushed stone sample with a gradation ofn 07 and a compaction level of no greater than20mm for the aggregate of the bedding course

Data Availability

(e data used to support the findings of this study areavailable from the author upon request

Conflicts of Interest

(e authors declare that they have no conflicts of interest

Acknowledgments

(e authors gratefully acknowledge the authors of thereferences

References

[1] S Watanabe ldquoStudy on storm water control by permeablepavement and infiltration pipesrdquo Water Science and Tech-nology vol 32 no 1 pp 25ndash32 1995

[2] W Schluter and C Jefferies ldquoModelling the outflow from aporous pavementrdquo Urban Water vol 4 no 3 pp 245ndash2532002

[3] A Benedetto ldquoA decision support system for the safety ofairport runways the case of heavy rainstormsrdquo TransportationResearch Part A Policy and Practice vol 36 no 8 pp 665ndash682 2002

[4] S Borgwardt and Y Chen ldquoStudy on long term permeabilityof permeable concrete pavement brick pavementrdquo BuildingBlock and Block Building vol 15 no 2 pp 37ndash41 2008

[5] A Beeldens L Vijverman and Y Cui ldquoExperience of usingpermeable pavement with paving brick in Belgium for 15yearsmdashpromoting application through legislationrdquo BuildingBlock and Block Building vol 23 no 1 pp 32ndash38 2016

[6] H Wang W Che and J Hu ldquoOn storm water infiltration inurban areardquo Water and Wastewater Engineering vol 27no 2 pp 4-5 2001

[7] B Wang and C Li ldquoPenetrative pavement and urban eco-logical and physical environmentrdquo Industrial Constructionvol 32 no 12 pp 29ndash31 2002

[8] B Wang ldquoApplication of penetrative pavement and itsprospectsrdquo Architecture Technology vol 33 no 9pp 659-660 2002

[9] S Wu Z Wang J Zhang J Xie and Y Wang ldquoExperimentalstudy on relationship among runoff coefficients of differentunderlying surfaces rainfall intensity and durationrdquo Journalof China Agricultural University vol 11 no 5 pp 55ndash592006

[10] Y Ding Y Huang Z Ma Z Zhong W Liu and B CaoldquoResearch of optimum mix proportion of permeable concretepacing blocks in rainwater harvesting in urban areardquo BeijingWater Resources vol 10 no 1 pp 12-13 2003

[11] N Zhang ldquoComparison and study on test methods for waterpermeability coefficients of permeable pavementrdquo Technologyof Highway and Transport vol 32 no 1 pp 6ndash9 2016

[12] W Zhang Y Ding and S Zhang ldquoStudy on water perme-ability durability of concrete permeable brickrdquo New BuildingMaterials vol 13 no 6 pp 22ndash24 2006

[13] L Hou S Feng Y Ding and S Zhang ldquoRunoff-rainfallrelationship for multilayer infiltration systems under artificialrainfallsrdquo Transactions of the Chinese Society of AgriculturalEngineering vol 22 no 9 pp 100ndash105 2006

[14] L Hou S Feng Z Han Y Ding and S Zhang ldquoExperimentalstudy on impacts of infiltration treated with porous pave-mentrdquo Journal of China Agricultural University vol 11 no 4pp 83ndash88 2006

[15] Y Meng T Li S Wang and Z Fu ldquoField survey and ap-plication analysis of infiltration performance of permeablepavements in Shanghai cityrdquo China Water and Wastewatervol 25 no 6 pp 29ndash33 2009

8 Advances in Civil Engineering

[16] L Huo Preparation Properties of Pervius Concrete PavementMaterial Southeast University Nanjing China 2004

[17] L Xu Q Li Y Wang J Huang and Y Xu ldquoAnalysis of thechanges in debris flow hazard in the context of climatechangerdquo Climate Change Research vol 16 no 4 pp 415ndash4232020

[18] J-C Chen W-S Huang and Y-F Tsai ldquoVariability in thecharacteristics of extreme rainfall events triggering debrisflows a case study in the Chenyulan watershed TaiwanrdquoNatural Hazards vol 102 no 3 pp 887ndash908 2020

[19] ASTM International ASTM C39C39M-15a Standard testmethod for compressive strength of cylindrical concrete speci-mens ASTM International West Conshohocken PA USA2015

[20] A N Talbot and F E Richart ldquo(e strength of concrete andits relation to the cement aggregate and waterrdquo BulletinUniversity of Illinois Engineering Experiment Station vol 11no 7 pp 1ndash118 1923

[21] L Wang and H Kong ldquoVariation characteristics of mass-lossrate in dynamic seepage system of the broken rocksrdquo Geo-fluids vol 2018 Article ID 7137601 17 pages 2018

[22] L Wang H Kong C Qiu and B Xu ldquoTime-varying char-acteristics on migration and loss of fine particles in fracturedmudstone under water flow scourrdquo Arabian Journal ofGeosciences vol 12 no 5 p 159 2019

[23] H Kong and L Wang ldquo(e mass loss behavior of fracturedrock in seepage process the development and application of anew seepage experimental systemrdquo Advances in Civil Engi-neering vol 2018 p 12 Article ID 7891914 2018

[24] G Lu ZWang P Liu DWang andM Oeser ldquoInvestigationof the hydraulic properties of pervious pavement mixturescharacterization of Darcy and non-Darcy flow based on poremicrostructuresrdquo Journal of Transportation Engineering PartB Pavements vol 146 no 2 Article ID 04020012 2020

[25] G Lu L Renken T Li D Wang H Li and M OeserldquoExperimental study on the polyurethane-bound perviousmixtures in the application of permeable pavementsrdquo Con-struction and Building Materials vol 202 pp 838ndash850 2019

[26] D Ma X Cai Z Zhou and X Li ldquoExperimental investigationon hydraulic properties of granular sandstone and mudstonemixturesrdquo Geofluids vol 2018 Article ID 9216578 13 pages2018

[27] L Wang H Kong Y Yin B Xu and D Zhang ldquoStrain-basednon-Darcy permeability properties in crushed rock accom-panying mass lossrdquo Arabian Journal of Geosciences vol 13no 11 p 406 2020

[28] H Kong and L Wang ldquo(e behavior of mass migration andloss in fractured rock during seepagerdquo Bulletin of EngineeringGeology and the Environment vol 79 no 2 pp 739ndash7542020

[29] L Wang Z Chen and H Kong ldquoAn experimental investi-gation for seepage-induced instability of confined brokenmudstones with consideration of mass lossrdquo Geofluidsvol 2017 Article ID 3057910 12 pages 2017

[30] L Wang H Kong and M Karakus ldquoHazard assessment ofgroundwater inrush in crushed rock mass an experimentalinvestigation of mass-loss-induced change of fluid flow be-haviorrdquo Engineering Geology vol 277 Article ID 1058122020

[31] J Wu G Han M Feng et al ldquoMass-loss effects on the flowbehavior in broken argillaceous red sandstone with differentparticle-size distributionsrdquo Comptes Rendus Mecaniquevol 347 no 6 pp 504ndash523 2019

Advances in Civil Engineering 9

600 L per hour(e double-action hydraulic cylinder with aninner diameter of 220mm has a piston with a diameter of160mm and its maximum traverse and volume are 500mmand 20 L respectively

(e data acquisition and analysis module includes dis-placement sensors flow sensors pressure sensors datacollectors PC etc (e particle recovery module includesvibrating sieves filter cloths an oven an electronic scale etc(e filter screen is the 300 meshes fine gauze and thecorresponding collected grains size could reach 48 microns(e pressure transducer has the measure traverse andmeasure accuracy of 16MPa and 2 kPa respectively

23 Test Procedure Figure 2 shows the test process (esamplersquos initial height was measured after the sample wascharged Because manual charging gave highly variableporosity after being packed into the permeameter sampleswere firstly subjected to 002MPa at 1mmmin for pre-liminary compression without crushing the particles (e

samplersquos actual height was then measured at this point basedon the displacement of the testing machine Water was theninjected to saturate the sample and start the permeation test(e pressure and flow data were recorded in real-timeduring the test (e lost particles were collected at definedintervals because they could not be measured in real-time(e mass loss of particles was relatively high at the start ofthe test and the interval for particle collection was initially setto 2min (e collection interval could then be graduallyincreased as the mass loss decreased over time

3 Results and Analysis

From the permeability test of the crushed stone aggregatedata such as water pressure flowrate and particle mass lossduring permeation in the sample were measured and thechange of physical quantities such as permeation velocitypermeability and particle loss were calculated andrationalized

31 Variation of Permeation Velocity During the test theflowrate Q was measured in real-time from which thepermeation velocity v could be calculated as follows

v Q

πa2 (3)

where a is the inner radius of the permeameter (a 50mm)(e permeation velocity was calculated from the real-

time flow in the test Figure 3 shows that the permeationprocess includes two phases corresponding to fast mass lossand slow permeation respectively and the change in per-meation velocity mainly occurred in the slow permeationphase During fast mass loss the permeation velocity in-creased because of rising porosity that resulted from themigration and loss of small particles Figure 3 shows that theduration of the mass loss stage varied for different samples

Table 1(e mass qualities of different diameters broken rock withdifferent Talbot power exponents

Mass (g) n04 05 06 07

Rock particle sizes

0ndash5mm 10506 8944 7615 64835ndash10mm 3357 3705 3927 404810ndash15mm 2441 2843 3179 345615ndash20mm 1988 2397 2773 312020ndash25mm 1708 2111 2506 2892

Particle recovery module

Axial load and displacement control module

Permeation moduleData acquisition and analysis module

Figure 1(e home-made permeability test system for broken rockwith variable mass

System debugging

Mixing and charging

Initial axial loading to 002MPa

Saturating

Seepage

Discharging

Analyzing data

Testing the system operation

Measuring the initial height

Measuring the actual height

Collecting lost fine particlesat regular intervals

Acquiring pore pressure andflow in real time

Figure 2 (e test process

Advances in Civil Engineering 3

because their contents of small particles that could migratewere different(e content of small particles was the smallestfor the n 07 sample whose mass loss phase lasted for onlyas short as 50 s In contrast the n 04 and n 05 sampleshad a relatively longer mass loss phase because they had ahigher content of small particles Particularly for the n 05sample with initial compaction of 20mm the mass lossphase lasted for nearly 930 s

Table 2 also shows a stepwise increase in the order ofmagnitude of the permeation velocity for samples with differentgradations at different levels of compaction For the n 04 andn 05 samples the permeation velocity always increased fromthe order of 10minus3ms to the order of 10minus2ms regardless ofcompaction level For the n 06 samples the permeationvelocity remained at the 10minus2ms level throughout the test whenthe initial compaction was 10mm but showed a lower initialpermeation velocity at the 10minus3ms level with higher initialcompactions For the n 07 samples the initial permeationvelocity was at the 10minus2ms level when the initial compactionswere 10minus30mm but decreased to the 10minus3ms level when theinitial compaction increased to 40mm (erefore the initialcompaction level had a significant impact on the permeationvelocity and affected the permeation velocity at the beginning ofthe test

32Variationof Permeability Lu et al [24 25] used a home-made permeameter to analyze the flow characteristics of

permeable pavement mixtures under different hydraulicgradients (e results show that Darcyrsquos law is not applicableto analyzing directional water transport in permeablepavement materials With rising hydraulic gradient theReynolds number of permeable pavement materials in-creases and the water flow in permeable pavement materialstransitions from Darcy flow to non-Darcy flow

(e Forchheimer equation was used to describe the non-Darcy flow of the permeation process for the aggregate inthis paper

minusnablap μk

v + ρβv2 (4)

where nablap is the pressure gradient μ is the dynamic viscosityof the fluid k is the permeability ρ is the fluid density and βis the non-Darcy factor

(e permeability k and non-Darcy factor β in Equation(4) are the two key parameters that describe the permeabilitycharacteristics of crushed stone and they can be calculated

000E + 00

500E ndash 03

100E ndash 02

150E ndash 02

200E ndash 02

250E ndash 02v (

ms

)

t (s)

1020

3040

0 200 400 600 800 1000

(a)

000E + 00

500E ndash 03

100E ndash 02

150E ndash 02

200E ndash 02

250E ndash 02

v (m

s)

t (s)

1020

3040

0 200 400 600 800 1000

(b)

000E + 00

500E ndash 03

100E ndash 02

150E ndash 02

200E ndash 02

250E ndash 02

v (m

s)

t (s)

1020

3040

0 200 400 600 800 1000

(c)

000E + 00

500E ndash 03

100E ndash 02

150E ndash 02

200E ndash 02

250E ndash 02

v (m

s)

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 3 (e permeation velocity of the mass loss stage varied for different samples (a) n 04 (b) n 05 (c) n 06 (d) n 07

Table 2 (e change of magnitudes of permeation velocity in thewhole test

10mm 20mm 30mm 40mm04 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2

05 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2

06 10minus2sim10minus2 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2

07 10minus2sim10minus2 10minus2sim10minus2 10minus2sim10minus2 10minus3sim10minus2

4 Advances in Civil Engineering

from the time series of the permeation velocity and thepressure gradient collected in the test [26]

k μ 1113936

ni1 v3i( 1113857

2minus 1113936

ni1 v

2i 1113936

ni1 v

4i1113960 1113961

1113936ni1 Δpiv

2i 1113936

ni1 v

3i minus 1113936

ni1 Δpivi 1113936

ni1 v

4i

β 1113936

ni1 Δpivi 1113936

ni1 v

3i minus 1113936

ni1 Δpiv

2i 1113936

ni1 v

2i

ρ 1113936ni1 v3i( 1113857

2minus 1113936

ni1 v

2i 1113936

ni1 v

4i1113960 1113961

(5)

Figure 4 shows how the permeability of samples withdifferent gradation under different compaction levels variedwith time(e permeability of all samples was at the order of10minus11ndash10minus10m2 during the entire permeation process (epermeability of all samples showed a sharp increase in therapid mass loss phase and the increase was concomitantwith the sudden change of flowrate It can be speculated thatthe sudden change of the flow led to the change of thesamplesrsquo permeability In the later part of the permeationtest the permeability only demonstrated minor vacillationand remained basically unchanged In addition gradationand compaction levels also affected the permeability of thesamples For example as seen in Figure 4 the n 05 samplehad the highest permeability of 27times10minus10m2 while then 07 sample only had a permeability no greater than44times10minus11m2 (e influence of compaction on permeabilityseemed to be somewhat irregular possibly due to the

randomness of particle arrangement when the samples werecharged into the device

(e permeability of the aggregate needs to be consideredin selecting aggregates for the bedding course of the per-meable road Ideally aggregates with relatively high per-meability should be chosen

Figure 5 shows the non-Darcy factors for differentsamples varied with time (e logarithmic form was used inthe figure because the non-Darcy factors varied acrossseveral orders of magnitude Contrary to permeability thenon-Darcy factors gradually decreased as time elapsed [27]

It is worth noting that the change in the permeability ofthe crushed stone aggregate during the permeation processwas related to the particle loss during the test

33 Particle Mass Loss During the permeation processsmall particles of crushed stone were carried by the waterflow and left the permeameter [28ndash31] (e lost particleswere collected at given time intervals at ∆ti (i 1 2 3 ) asshown in Figure 6 and their mass after drying was weighedand recorded asmi (i 1 2 3 ) In this way the total massloss 1113936 mi during the permeation process could be calculatedIt can be seen from Figure 6 that the size of the lost particlesranged mostly in 0ndash2mm and the amount of collectedparticles gradually decreased as time elapsed

Figure 7 shows the mass loss of crushed stone aggregateswith different gradations It could be found that as the

000E + 00

400E ndash 11

800E ndash 11

120E ndash 10

160E ndash 10

200E ndash 10k

(m2 )

t (s)

1020

3040

0 200 400 600 800 1000

(a)

000E + 00

100E ndash 10

500E ndash 11

150E ndash 10

200E ndash 10

250E ndash 10

300E ndash 10

k (m

2 )

t (s)

1020

3040

0 200 400 600 800 1000

(b)

000E + 00

200E ndash 11

400E ndash 11

600E ndash 11

800E ndash 11

100E ndash 10

k (m

2 )

t (s)

1020

3040

0 200 400 600 800 1000

(c)

000E + 00

100E ndash 11

200E ndash 11

300E ndash 11

400E ndash 11

500E ndash 11

k (m

2 )

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 4(e permeability of samples with different gradation under different compaction levels varied with time (a) n 04 (b) n 05 (c)n 06 (d) n 07

Advances in Civil Engineering 5

gradation increased the content of fine particles decreasedAlthough some secondary small particles were producedduring the permeation process from water-rock interactionthe mass loss still mainly came from the original smallparticles (erefore the mass loss decreased with risinggradation (e n 04 sample had the highest mass loss ofabout 280 g while the n 07 sample had a maximum massloss of 48 g which was only 17 that of the n 04 sample

For samples with the same gradation the mass lossincreased with intensifying compaction For example themass loss of the n 06 sample under 40mm compaction was452 of its mass loss under 10mm compaction In contrastthe mass loss of the n 05 sample under 40mm compactionwas 175 of its mass loss under 10mm compaction (edifference in these increments was related to factors such asgradation and the particle arrangement during samplecharging It could be seen that gradation and compactionhave significant impact on the mass loss In selecting theaggregate of the bedding course for permeable roads it is

crucial to determine the gradation and the correspondingcompaction to ensure structural stability

Figure 7 also shows that the rate of mass loss differedbetween samples For example for samples with the samecompaction level of 10mm themass loss rate decreased withrising gradation (e maximum mass loss rate of the n 04and n 07 samples reached 83 gs and 005 gs respectively(e former was 166 times the latter (e mass loss rate ofsamples with the same gradation but different compactionalso varied significantly For example the maximum massloss rate of the n 05 sample with 30mm and 20mmcompaction reached 586 gs and 0054 gs respectivelywhich were two orders of magnitude apart

4 Discussion

(e permeability mass loss and mass loss rate of all sampleswere classified based on the relevant specifications of per-meable roads with the standard being 20times10minus11m2 100 g

0

5

10

15

20

25

30ln

(β)(

mndash1

)

t (s)

1020

3040

0 200 400 600 800 1000

(a)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(b)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(c)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 5 (e non-Darcy factor of samples with different gradation under different compaction levels varied with time (a) n 04 (b)n 05 (c) n 06 (d) n 07

m1m2 m3 m4 m5

Figure 6 (e lost particles collected at given time intervals

6 Advances in Civil Engineering

and 05 gs respectively Accordingly the tested samples andcompactions were categorized into three sets recommended(R) not recommended (N) and uncertain (U) (e optimalgradation and compaction levels were then derivedstatistically

It can be found from Table 3 that the permeability ofmost samples satisfied the requirements as an aggregate forpermeable road but samples with smaller gradation had a

higher mass loss during permeation which may affect thestructural stability of the bedding course For samples with amass loss less than 5 structural instability could also occurif the mass loss rate was too high (us the overall rec-ommendation was to use crushed stone with a gradation ofn 07 and adopt a compaction level of no more than 20mmin choosing crushed stone as the aggregate for the beddingcourse of permeable roads It should be noted that adhesives

0

50

100

150

200

250

300summ

i (g)

t (s)

1020

3040

0 200 400 600 800 1000

(a)

0

50

100

150

200

250

300

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(b)

0

50

100

150

200

250

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(c)

0

10

20

30

40

50

60

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 7 (e mass loss of crushed stone aggregates with different gradation (a) n 04 (b) n 05 (c) n 06 (d) n 07

Table 3 (e optimal gradation and compaction levels

Gradation andinitial compression Permeability Mass loss (e mass loss rate

04

10 R R N20 R N N30 R N N40 R N R

05

10 R N N20 U N R30 R N N40 R N N

06

10 N R R20 R N N30 R N N40 R N N

07

10 R R R20 R R R30 N U R40 N U R

Advances in Civil Engineering 7

were not used in this study (e use of adhesives will changethe permeability and particle loss of the bedding course

5 Conclusions

(e aggregate for the bedding course of permeable roadsneeds to not only meet the requirements of basic mechanicalproperties such as compressive strength and shear strengthbut also ensure permeability and structural stability (iswork analyzed permeability under extreme rainfall condi-tions and the particle mass loss during permeation and theninvestigated the stability of crushed stone aggregate andexamined the optimal gradation and compaction of thecrushed stone aggregate in engineering applications (emain conclusions are as follows

(1) (e permeation process included two phases thefirst being rapid mass loss and the second being slowpermeation (e change of permeation velocitymainly occurred in the first phase (e duration ofthe rapid mass loss phase varied for samples withdifferent gradations because of their differingamount of small particles that could migrate (epermeation velocity of samples with different gra-dations at different compaction levels showed astepwise change in its order of magnitude

(2) (roughout the permeation process the perme-ability of samples with various gradations was all atthe order of 10minus11ndash10minus10m2 (e change in perme-ability coincided with the change in flowrate mostprobably because of the sudden change of the flowaltered the permeability of the sample Factors suchas gradation compaction and the randomness ofparticles arrangement in the crushed stone duringsample charging all affected the permeability of thesample

(3) During the permeation process the mass loss de-creased with rising gradation (e mass loss of thesamples with the same gradation generally increasedwith intensifying compaction It could be seen thatgradation and compaction had strong influence onparticle mass loss (erefore ensuring the structuralstability of permeable road necessitates careful se-lection of the gradation and compaction for thecrushed stone aggregate

(4) (e permeability of most samples could satisfy therequirements as the aggregate but structural stabilityof the bedding course of the permeable road may beat stake if the sample had a high mass loss or massloss rate during permeation It is recommended touse the crushed stone sample with a gradation ofn 07 and a compaction level of no greater than20mm for the aggregate of the bedding course

Data Availability

(e data used to support the findings of this study areavailable from the author upon request

Conflicts of Interest

(e authors declare that they have no conflicts of interest

Acknowledgments

(e authors gratefully acknowledge the authors of thereferences

References

[1] S Watanabe ldquoStudy on storm water control by permeablepavement and infiltration pipesrdquo Water Science and Tech-nology vol 32 no 1 pp 25ndash32 1995

[2] W Schluter and C Jefferies ldquoModelling the outflow from aporous pavementrdquo Urban Water vol 4 no 3 pp 245ndash2532002

[3] A Benedetto ldquoA decision support system for the safety ofairport runways the case of heavy rainstormsrdquo TransportationResearch Part A Policy and Practice vol 36 no 8 pp 665ndash682 2002

[4] S Borgwardt and Y Chen ldquoStudy on long term permeabilityof permeable concrete pavement brick pavementrdquo BuildingBlock and Block Building vol 15 no 2 pp 37ndash41 2008

[5] A Beeldens L Vijverman and Y Cui ldquoExperience of usingpermeable pavement with paving brick in Belgium for 15yearsmdashpromoting application through legislationrdquo BuildingBlock and Block Building vol 23 no 1 pp 32ndash38 2016

[6] H Wang W Che and J Hu ldquoOn storm water infiltration inurban areardquo Water and Wastewater Engineering vol 27no 2 pp 4-5 2001

[7] B Wang and C Li ldquoPenetrative pavement and urban eco-logical and physical environmentrdquo Industrial Constructionvol 32 no 12 pp 29ndash31 2002

[8] B Wang ldquoApplication of penetrative pavement and itsprospectsrdquo Architecture Technology vol 33 no 9pp 659-660 2002

[9] S Wu Z Wang J Zhang J Xie and Y Wang ldquoExperimentalstudy on relationship among runoff coefficients of differentunderlying surfaces rainfall intensity and durationrdquo Journalof China Agricultural University vol 11 no 5 pp 55ndash592006

[10] Y Ding Y Huang Z Ma Z Zhong W Liu and B CaoldquoResearch of optimum mix proportion of permeable concretepacing blocks in rainwater harvesting in urban areardquo BeijingWater Resources vol 10 no 1 pp 12-13 2003

[11] N Zhang ldquoComparison and study on test methods for waterpermeability coefficients of permeable pavementrdquo Technologyof Highway and Transport vol 32 no 1 pp 6ndash9 2016

[12] W Zhang Y Ding and S Zhang ldquoStudy on water perme-ability durability of concrete permeable brickrdquo New BuildingMaterials vol 13 no 6 pp 22ndash24 2006

[13] L Hou S Feng Y Ding and S Zhang ldquoRunoff-rainfallrelationship for multilayer infiltration systems under artificialrainfallsrdquo Transactions of the Chinese Society of AgriculturalEngineering vol 22 no 9 pp 100ndash105 2006

[14] L Hou S Feng Z Han Y Ding and S Zhang ldquoExperimentalstudy on impacts of infiltration treated with porous pave-mentrdquo Journal of China Agricultural University vol 11 no 4pp 83ndash88 2006

[15] Y Meng T Li S Wang and Z Fu ldquoField survey and ap-plication analysis of infiltration performance of permeablepavements in Shanghai cityrdquo China Water and Wastewatervol 25 no 6 pp 29ndash33 2009

8 Advances in Civil Engineering

[16] L Huo Preparation Properties of Pervius Concrete PavementMaterial Southeast University Nanjing China 2004

[17] L Xu Q Li Y Wang J Huang and Y Xu ldquoAnalysis of thechanges in debris flow hazard in the context of climatechangerdquo Climate Change Research vol 16 no 4 pp 415ndash4232020

[18] J-C Chen W-S Huang and Y-F Tsai ldquoVariability in thecharacteristics of extreme rainfall events triggering debrisflows a case study in the Chenyulan watershed TaiwanrdquoNatural Hazards vol 102 no 3 pp 887ndash908 2020

[19] ASTM International ASTM C39C39M-15a Standard testmethod for compressive strength of cylindrical concrete speci-mens ASTM International West Conshohocken PA USA2015

[20] A N Talbot and F E Richart ldquo(e strength of concrete andits relation to the cement aggregate and waterrdquo BulletinUniversity of Illinois Engineering Experiment Station vol 11no 7 pp 1ndash118 1923

[21] L Wang and H Kong ldquoVariation characteristics of mass-lossrate in dynamic seepage system of the broken rocksrdquo Geo-fluids vol 2018 Article ID 7137601 17 pages 2018

[22] L Wang H Kong C Qiu and B Xu ldquoTime-varying char-acteristics on migration and loss of fine particles in fracturedmudstone under water flow scourrdquo Arabian Journal ofGeosciences vol 12 no 5 p 159 2019

[23] H Kong and L Wang ldquo(e mass loss behavior of fracturedrock in seepage process the development and application of anew seepage experimental systemrdquo Advances in Civil Engi-neering vol 2018 p 12 Article ID 7891914 2018

[24] G Lu ZWang P Liu DWang andM Oeser ldquoInvestigationof the hydraulic properties of pervious pavement mixturescharacterization of Darcy and non-Darcy flow based on poremicrostructuresrdquo Journal of Transportation Engineering PartB Pavements vol 146 no 2 Article ID 04020012 2020

[25] G Lu L Renken T Li D Wang H Li and M OeserldquoExperimental study on the polyurethane-bound perviousmixtures in the application of permeable pavementsrdquo Con-struction and Building Materials vol 202 pp 838ndash850 2019

[26] D Ma X Cai Z Zhou and X Li ldquoExperimental investigationon hydraulic properties of granular sandstone and mudstonemixturesrdquo Geofluids vol 2018 Article ID 9216578 13 pages2018

[27] L Wang H Kong Y Yin B Xu and D Zhang ldquoStrain-basednon-Darcy permeability properties in crushed rock accom-panying mass lossrdquo Arabian Journal of Geosciences vol 13no 11 p 406 2020

[28] H Kong and L Wang ldquo(e behavior of mass migration andloss in fractured rock during seepagerdquo Bulletin of EngineeringGeology and the Environment vol 79 no 2 pp 739ndash7542020

[29] L Wang Z Chen and H Kong ldquoAn experimental investi-gation for seepage-induced instability of confined brokenmudstones with consideration of mass lossrdquo Geofluidsvol 2017 Article ID 3057910 12 pages 2017

[30] L Wang H Kong and M Karakus ldquoHazard assessment ofgroundwater inrush in crushed rock mass an experimentalinvestigation of mass-loss-induced change of fluid flow be-haviorrdquo Engineering Geology vol 277 Article ID 1058122020

[31] J Wu G Han M Feng et al ldquoMass-loss effects on the flowbehavior in broken argillaceous red sandstone with differentparticle-size distributionsrdquo Comptes Rendus Mecaniquevol 347 no 6 pp 504ndash523 2019

Advances in Civil Engineering 9

because their contents of small particles that could migratewere different(e content of small particles was the smallestfor the n 07 sample whose mass loss phase lasted for onlyas short as 50 s In contrast the n 04 and n 05 sampleshad a relatively longer mass loss phase because they had ahigher content of small particles Particularly for the n 05sample with initial compaction of 20mm the mass lossphase lasted for nearly 930 s

Table 2 also shows a stepwise increase in the order ofmagnitude of the permeation velocity for samples with differentgradations at different levels of compaction For the n 04 andn 05 samples the permeation velocity always increased fromthe order of 10minus3ms to the order of 10minus2ms regardless ofcompaction level For the n 06 samples the permeationvelocity remained at the 10minus2ms level throughout the test whenthe initial compaction was 10mm but showed a lower initialpermeation velocity at the 10minus3ms level with higher initialcompactions For the n 07 samples the initial permeationvelocity was at the 10minus2ms level when the initial compactionswere 10minus30mm but decreased to the 10minus3ms level when theinitial compaction increased to 40mm (erefore the initialcompaction level had a significant impact on the permeationvelocity and affected the permeation velocity at the beginning ofthe test

32Variationof Permeability Lu et al [24 25] used a home-made permeameter to analyze the flow characteristics of

permeable pavement mixtures under different hydraulicgradients (e results show that Darcyrsquos law is not applicableto analyzing directional water transport in permeablepavement materials With rising hydraulic gradient theReynolds number of permeable pavement materials in-creases and the water flow in permeable pavement materialstransitions from Darcy flow to non-Darcy flow

(e Forchheimer equation was used to describe the non-Darcy flow of the permeation process for the aggregate inthis paper

minusnablap μk

v + ρβv2 (4)

where nablap is the pressure gradient μ is the dynamic viscosityof the fluid k is the permeability ρ is the fluid density and βis the non-Darcy factor

(e permeability k and non-Darcy factor β in Equation(4) are the two key parameters that describe the permeabilitycharacteristics of crushed stone and they can be calculated

000E + 00

500E ndash 03

100E ndash 02

150E ndash 02

200E ndash 02

250E ndash 02v (

ms

)

t (s)

1020

3040

0 200 400 600 800 1000

(a)

000E + 00

500E ndash 03

100E ndash 02

150E ndash 02

200E ndash 02

250E ndash 02

v (m

s)

t (s)

1020

3040

0 200 400 600 800 1000

(b)

000E + 00

500E ndash 03

100E ndash 02

150E ndash 02

200E ndash 02

250E ndash 02

v (m

s)

t (s)

1020

3040

0 200 400 600 800 1000

(c)

000E + 00

500E ndash 03

100E ndash 02

150E ndash 02

200E ndash 02

250E ndash 02

v (m

s)

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 3 (e permeation velocity of the mass loss stage varied for different samples (a) n 04 (b) n 05 (c) n 06 (d) n 07

Table 2 (e change of magnitudes of permeation velocity in thewhole test

10mm 20mm 30mm 40mm04 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2

05 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2

06 10minus2sim10minus2 10minus3sim10minus2 10minus3sim10minus2 10minus3sim10minus2

07 10minus2sim10minus2 10minus2sim10minus2 10minus2sim10minus2 10minus3sim10minus2

4 Advances in Civil Engineering

from the time series of the permeation velocity and thepressure gradient collected in the test [26]

k μ 1113936

ni1 v3i( 1113857

2minus 1113936

ni1 v

2i 1113936

ni1 v

4i1113960 1113961

1113936ni1 Δpiv

2i 1113936

ni1 v

3i minus 1113936

ni1 Δpivi 1113936

ni1 v

4i

β 1113936

ni1 Δpivi 1113936

ni1 v

3i minus 1113936

ni1 Δpiv

2i 1113936

ni1 v

2i

ρ 1113936ni1 v3i( 1113857

2minus 1113936

ni1 v

2i 1113936

ni1 v

4i1113960 1113961

(5)

Figure 4 shows how the permeability of samples withdifferent gradation under different compaction levels variedwith time(e permeability of all samples was at the order of10minus11ndash10minus10m2 during the entire permeation process (epermeability of all samples showed a sharp increase in therapid mass loss phase and the increase was concomitantwith the sudden change of flowrate It can be speculated thatthe sudden change of the flow led to the change of thesamplesrsquo permeability In the later part of the permeationtest the permeability only demonstrated minor vacillationand remained basically unchanged In addition gradationand compaction levels also affected the permeability of thesamples For example as seen in Figure 4 the n 05 samplehad the highest permeability of 27times10minus10m2 while then 07 sample only had a permeability no greater than44times10minus11m2 (e influence of compaction on permeabilityseemed to be somewhat irregular possibly due to the

randomness of particle arrangement when the samples werecharged into the device

(e permeability of the aggregate needs to be consideredin selecting aggregates for the bedding course of the per-meable road Ideally aggregates with relatively high per-meability should be chosen

Figure 5 shows the non-Darcy factors for differentsamples varied with time (e logarithmic form was used inthe figure because the non-Darcy factors varied acrossseveral orders of magnitude Contrary to permeability thenon-Darcy factors gradually decreased as time elapsed [27]

It is worth noting that the change in the permeability ofthe crushed stone aggregate during the permeation processwas related to the particle loss during the test

33 Particle Mass Loss During the permeation processsmall particles of crushed stone were carried by the waterflow and left the permeameter [28ndash31] (e lost particleswere collected at given time intervals at ∆ti (i 1 2 3 ) asshown in Figure 6 and their mass after drying was weighedand recorded asmi (i 1 2 3 ) In this way the total massloss 1113936 mi during the permeation process could be calculatedIt can be seen from Figure 6 that the size of the lost particlesranged mostly in 0ndash2mm and the amount of collectedparticles gradually decreased as time elapsed

Figure 7 shows the mass loss of crushed stone aggregateswith different gradations It could be found that as the

000E + 00

400E ndash 11

800E ndash 11

120E ndash 10

160E ndash 10

200E ndash 10k

(m2 )

t (s)

1020

3040

0 200 400 600 800 1000

(a)

000E + 00

100E ndash 10

500E ndash 11

150E ndash 10

200E ndash 10

250E ndash 10

300E ndash 10

k (m

2 )

t (s)

1020

3040

0 200 400 600 800 1000

(b)

000E + 00

200E ndash 11

400E ndash 11

600E ndash 11

800E ndash 11

100E ndash 10

k (m

2 )

t (s)

1020

3040

0 200 400 600 800 1000

(c)

000E + 00

100E ndash 11

200E ndash 11

300E ndash 11

400E ndash 11

500E ndash 11

k (m

2 )

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 4(e permeability of samples with different gradation under different compaction levels varied with time (a) n 04 (b) n 05 (c)n 06 (d) n 07

Advances in Civil Engineering 5

gradation increased the content of fine particles decreasedAlthough some secondary small particles were producedduring the permeation process from water-rock interactionthe mass loss still mainly came from the original smallparticles (erefore the mass loss decreased with risinggradation (e n 04 sample had the highest mass loss ofabout 280 g while the n 07 sample had a maximum massloss of 48 g which was only 17 that of the n 04 sample

For samples with the same gradation the mass lossincreased with intensifying compaction For example themass loss of the n 06 sample under 40mm compaction was452 of its mass loss under 10mm compaction In contrastthe mass loss of the n 05 sample under 40mm compactionwas 175 of its mass loss under 10mm compaction (edifference in these increments was related to factors such asgradation and the particle arrangement during samplecharging It could be seen that gradation and compactionhave significant impact on the mass loss In selecting theaggregate of the bedding course for permeable roads it is

crucial to determine the gradation and the correspondingcompaction to ensure structural stability

Figure 7 also shows that the rate of mass loss differedbetween samples For example for samples with the samecompaction level of 10mm themass loss rate decreased withrising gradation (e maximum mass loss rate of the n 04and n 07 samples reached 83 gs and 005 gs respectively(e former was 166 times the latter (e mass loss rate ofsamples with the same gradation but different compactionalso varied significantly For example the maximum massloss rate of the n 05 sample with 30mm and 20mmcompaction reached 586 gs and 0054 gs respectivelywhich were two orders of magnitude apart

4 Discussion

(e permeability mass loss and mass loss rate of all sampleswere classified based on the relevant specifications of per-meable roads with the standard being 20times10minus11m2 100 g

0

5

10

15

20

25

30ln

(β)(

mndash1

)

t (s)

1020

3040

0 200 400 600 800 1000

(a)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(b)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(c)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 5 (e non-Darcy factor of samples with different gradation under different compaction levels varied with time (a) n 04 (b)n 05 (c) n 06 (d) n 07

m1m2 m3 m4 m5

Figure 6 (e lost particles collected at given time intervals

6 Advances in Civil Engineering

and 05 gs respectively Accordingly the tested samples andcompactions were categorized into three sets recommended(R) not recommended (N) and uncertain (U) (e optimalgradation and compaction levels were then derivedstatistically

It can be found from Table 3 that the permeability ofmost samples satisfied the requirements as an aggregate forpermeable road but samples with smaller gradation had a

higher mass loss during permeation which may affect thestructural stability of the bedding course For samples with amass loss less than 5 structural instability could also occurif the mass loss rate was too high (us the overall rec-ommendation was to use crushed stone with a gradation ofn 07 and adopt a compaction level of no more than 20mmin choosing crushed stone as the aggregate for the beddingcourse of permeable roads It should be noted that adhesives

0

50

100

150

200

250

300summ

i (g)

t (s)

1020

3040

0 200 400 600 800 1000

(a)

0

50

100

150

200

250

300

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(b)

0

50

100

150

200

250

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(c)

0

10

20

30

40

50

60

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 7 (e mass loss of crushed stone aggregates with different gradation (a) n 04 (b) n 05 (c) n 06 (d) n 07

Table 3 (e optimal gradation and compaction levels

Gradation andinitial compression Permeability Mass loss (e mass loss rate

04

10 R R N20 R N N30 R N N40 R N R

05

10 R N N20 U N R30 R N N40 R N N

06

10 N R R20 R N N30 R N N40 R N N

07

10 R R R20 R R R30 N U R40 N U R

Advances in Civil Engineering 7

were not used in this study (e use of adhesives will changethe permeability and particle loss of the bedding course

5 Conclusions

(e aggregate for the bedding course of permeable roadsneeds to not only meet the requirements of basic mechanicalproperties such as compressive strength and shear strengthbut also ensure permeability and structural stability (iswork analyzed permeability under extreme rainfall condi-tions and the particle mass loss during permeation and theninvestigated the stability of crushed stone aggregate andexamined the optimal gradation and compaction of thecrushed stone aggregate in engineering applications (emain conclusions are as follows

(1) (e permeation process included two phases thefirst being rapid mass loss and the second being slowpermeation (e change of permeation velocitymainly occurred in the first phase (e duration ofthe rapid mass loss phase varied for samples withdifferent gradations because of their differingamount of small particles that could migrate (epermeation velocity of samples with different gra-dations at different compaction levels showed astepwise change in its order of magnitude

(2) (roughout the permeation process the perme-ability of samples with various gradations was all atthe order of 10minus11ndash10minus10m2 (e change in perme-ability coincided with the change in flowrate mostprobably because of the sudden change of the flowaltered the permeability of the sample Factors suchas gradation compaction and the randomness ofparticles arrangement in the crushed stone duringsample charging all affected the permeability of thesample

(3) During the permeation process the mass loss de-creased with rising gradation (e mass loss of thesamples with the same gradation generally increasedwith intensifying compaction It could be seen thatgradation and compaction had strong influence onparticle mass loss (erefore ensuring the structuralstability of permeable road necessitates careful se-lection of the gradation and compaction for thecrushed stone aggregate

(4) (e permeability of most samples could satisfy therequirements as the aggregate but structural stabilityof the bedding course of the permeable road may beat stake if the sample had a high mass loss or massloss rate during permeation It is recommended touse the crushed stone sample with a gradation ofn 07 and a compaction level of no greater than20mm for the aggregate of the bedding course

Data Availability

(e data used to support the findings of this study areavailable from the author upon request

Conflicts of Interest

(e authors declare that they have no conflicts of interest

Acknowledgments

(e authors gratefully acknowledge the authors of thereferences

References

[1] S Watanabe ldquoStudy on storm water control by permeablepavement and infiltration pipesrdquo Water Science and Tech-nology vol 32 no 1 pp 25ndash32 1995

[2] W Schluter and C Jefferies ldquoModelling the outflow from aporous pavementrdquo Urban Water vol 4 no 3 pp 245ndash2532002

[3] A Benedetto ldquoA decision support system for the safety ofairport runways the case of heavy rainstormsrdquo TransportationResearch Part A Policy and Practice vol 36 no 8 pp 665ndash682 2002

[4] S Borgwardt and Y Chen ldquoStudy on long term permeabilityof permeable concrete pavement brick pavementrdquo BuildingBlock and Block Building vol 15 no 2 pp 37ndash41 2008

[5] A Beeldens L Vijverman and Y Cui ldquoExperience of usingpermeable pavement with paving brick in Belgium for 15yearsmdashpromoting application through legislationrdquo BuildingBlock and Block Building vol 23 no 1 pp 32ndash38 2016

[6] H Wang W Che and J Hu ldquoOn storm water infiltration inurban areardquo Water and Wastewater Engineering vol 27no 2 pp 4-5 2001

[7] B Wang and C Li ldquoPenetrative pavement and urban eco-logical and physical environmentrdquo Industrial Constructionvol 32 no 12 pp 29ndash31 2002

[8] B Wang ldquoApplication of penetrative pavement and itsprospectsrdquo Architecture Technology vol 33 no 9pp 659-660 2002

[9] S Wu Z Wang J Zhang J Xie and Y Wang ldquoExperimentalstudy on relationship among runoff coefficients of differentunderlying surfaces rainfall intensity and durationrdquo Journalof China Agricultural University vol 11 no 5 pp 55ndash592006

[10] Y Ding Y Huang Z Ma Z Zhong W Liu and B CaoldquoResearch of optimum mix proportion of permeable concretepacing blocks in rainwater harvesting in urban areardquo BeijingWater Resources vol 10 no 1 pp 12-13 2003

[11] N Zhang ldquoComparison and study on test methods for waterpermeability coefficients of permeable pavementrdquo Technologyof Highway and Transport vol 32 no 1 pp 6ndash9 2016

[12] W Zhang Y Ding and S Zhang ldquoStudy on water perme-ability durability of concrete permeable brickrdquo New BuildingMaterials vol 13 no 6 pp 22ndash24 2006

[13] L Hou S Feng Y Ding and S Zhang ldquoRunoff-rainfallrelationship for multilayer infiltration systems under artificialrainfallsrdquo Transactions of the Chinese Society of AgriculturalEngineering vol 22 no 9 pp 100ndash105 2006

[14] L Hou S Feng Z Han Y Ding and S Zhang ldquoExperimentalstudy on impacts of infiltration treated with porous pave-mentrdquo Journal of China Agricultural University vol 11 no 4pp 83ndash88 2006

[15] Y Meng T Li S Wang and Z Fu ldquoField survey and ap-plication analysis of infiltration performance of permeablepavements in Shanghai cityrdquo China Water and Wastewatervol 25 no 6 pp 29ndash33 2009

8 Advances in Civil Engineering

[16] L Huo Preparation Properties of Pervius Concrete PavementMaterial Southeast University Nanjing China 2004

[17] L Xu Q Li Y Wang J Huang and Y Xu ldquoAnalysis of thechanges in debris flow hazard in the context of climatechangerdquo Climate Change Research vol 16 no 4 pp 415ndash4232020

[18] J-C Chen W-S Huang and Y-F Tsai ldquoVariability in thecharacteristics of extreme rainfall events triggering debrisflows a case study in the Chenyulan watershed TaiwanrdquoNatural Hazards vol 102 no 3 pp 887ndash908 2020

[19] ASTM International ASTM C39C39M-15a Standard testmethod for compressive strength of cylindrical concrete speci-mens ASTM International West Conshohocken PA USA2015

[20] A N Talbot and F E Richart ldquo(e strength of concrete andits relation to the cement aggregate and waterrdquo BulletinUniversity of Illinois Engineering Experiment Station vol 11no 7 pp 1ndash118 1923

[21] L Wang and H Kong ldquoVariation characteristics of mass-lossrate in dynamic seepage system of the broken rocksrdquo Geo-fluids vol 2018 Article ID 7137601 17 pages 2018

[22] L Wang H Kong C Qiu and B Xu ldquoTime-varying char-acteristics on migration and loss of fine particles in fracturedmudstone under water flow scourrdquo Arabian Journal ofGeosciences vol 12 no 5 p 159 2019

[23] H Kong and L Wang ldquo(e mass loss behavior of fracturedrock in seepage process the development and application of anew seepage experimental systemrdquo Advances in Civil Engi-neering vol 2018 p 12 Article ID 7891914 2018

[24] G Lu ZWang P Liu DWang andM Oeser ldquoInvestigationof the hydraulic properties of pervious pavement mixturescharacterization of Darcy and non-Darcy flow based on poremicrostructuresrdquo Journal of Transportation Engineering PartB Pavements vol 146 no 2 Article ID 04020012 2020

[25] G Lu L Renken T Li D Wang H Li and M OeserldquoExperimental study on the polyurethane-bound perviousmixtures in the application of permeable pavementsrdquo Con-struction and Building Materials vol 202 pp 838ndash850 2019

[26] D Ma X Cai Z Zhou and X Li ldquoExperimental investigationon hydraulic properties of granular sandstone and mudstonemixturesrdquo Geofluids vol 2018 Article ID 9216578 13 pages2018

[27] L Wang H Kong Y Yin B Xu and D Zhang ldquoStrain-basednon-Darcy permeability properties in crushed rock accom-panying mass lossrdquo Arabian Journal of Geosciences vol 13no 11 p 406 2020

[28] H Kong and L Wang ldquo(e behavior of mass migration andloss in fractured rock during seepagerdquo Bulletin of EngineeringGeology and the Environment vol 79 no 2 pp 739ndash7542020

[29] L Wang Z Chen and H Kong ldquoAn experimental investi-gation for seepage-induced instability of confined brokenmudstones with consideration of mass lossrdquo Geofluidsvol 2017 Article ID 3057910 12 pages 2017

[30] L Wang H Kong and M Karakus ldquoHazard assessment ofgroundwater inrush in crushed rock mass an experimentalinvestigation of mass-loss-induced change of fluid flow be-haviorrdquo Engineering Geology vol 277 Article ID 1058122020

[31] J Wu G Han M Feng et al ldquoMass-loss effects on the flowbehavior in broken argillaceous red sandstone with differentparticle-size distributionsrdquo Comptes Rendus Mecaniquevol 347 no 6 pp 504ndash523 2019

Advances in Civil Engineering 9

from the time series of the permeation velocity and thepressure gradient collected in the test [26]

k μ 1113936

ni1 v3i( 1113857

2minus 1113936

ni1 v

2i 1113936

ni1 v

4i1113960 1113961

1113936ni1 Δpiv

2i 1113936

ni1 v

3i minus 1113936

ni1 Δpivi 1113936

ni1 v

4i

β 1113936

ni1 Δpivi 1113936

ni1 v

3i minus 1113936

ni1 Δpiv

2i 1113936

ni1 v

2i

ρ 1113936ni1 v3i( 1113857

2minus 1113936

ni1 v

2i 1113936

ni1 v

4i1113960 1113961

(5)

Figure 4 shows how the permeability of samples withdifferent gradation under different compaction levels variedwith time(e permeability of all samples was at the order of10minus11ndash10minus10m2 during the entire permeation process (epermeability of all samples showed a sharp increase in therapid mass loss phase and the increase was concomitantwith the sudden change of flowrate It can be speculated thatthe sudden change of the flow led to the change of thesamplesrsquo permeability In the later part of the permeationtest the permeability only demonstrated minor vacillationand remained basically unchanged In addition gradationand compaction levels also affected the permeability of thesamples For example as seen in Figure 4 the n 05 samplehad the highest permeability of 27times10minus10m2 while then 07 sample only had a permeability no greater than44times10minus11m2 (e influence of compaction on permeabilityseemed to be somewhat irregular possibly due to the

randomness of particle arrangement when the samples werecharged into the device

(e permeability of the aggregate needs to be consideredin selecting aggregates for the bedding course of the per-meable road Ideally aggregates with relatively high per-meability should be chosen

Figure 5 shows the non-Darcy factors for differentsamples varied with time (e logarithmic form was used inthe figure because the non-Darcy factors varied acrossseveral orders of magnitude Contrary to permeability thenon-Darcy factors gradually decreased as time elapsed [27]

It is worth noting that the change in the permeability ofthe crushed stone aggregate during the permeation processwas related to the particle loss during the test

33 Particle Mass Loss During the permeation processsmall particles of crushed stone were carried by the waterflow and left the permeameter [28ndash31] (e lost particleswere collected at given time intervals at ∆ti (i 1 2 3 ) asshown in Figure 6 and their mass after drying was weighedand recorded asmi (i 1 2 3 ) In this way the total massloss 1113936 mi during the permeation process could be calculatedIt can be seen from Figure 6 that the size of the lost particlesranged mostly in 0ndash2mm and the amount of collectedparticles gradually decreased as time elapsed

Figure 7 shows the mass loss of crushed stone aggregateswith different gradations It could be found that as the

000E + 00

400E ndash 11

800E ndash 11

120E ndash 10

160E ndash 10

200E ndash 10k

(m2 )

t (s)

1020

3040

0 200 400 600 800 1000

(a)

000E + 00

100E ndash 10

500E ndash 11

150E ndash 10

200E ndash 10

250E ndash 10

300E ndash 10

k (m

2 )

t (s)

1020

3040

0 200 400 600 800 1000

(b)

000E + 00

200E ndash 11

400E ndash 11

600E ndash 11

800E ndash 11

100E ndash 10

k (m

2 )

t (s)

1020

3040

0 200 400 600 800 1000

(c)

000E + 00

100E ndash 11

200E ndash 11

300E ndash 11

400E ndash 11

500E ndash 11

k (m

2 )

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 4(e permeability of samples with different gradation under different compaction levels varied with time (a) n 04 (b) n 05 (c)n 06 (d) n 07

Advances in Civil Engineering 5

gradation increased the content of fine particles decreasedAlthough some secondary small particles were producedduring the permeation process from water-rock interactionthe mass loss still mainly came from the original smallparticles (erefore the mass loss decreased with risinggradation (e n 04 sample had the highest mass loss ofabout 280 g while the n 07 sample had a maximum massloss of 48 g which was only 17 that of the n 04 sample

For samples with the same gradation the mass lossincreased with intensifying compaction For example themass loss of the n 06 sample under 40mm compaction was452 of its mass loss under 10mm compaction In contrastthe mass loss of the n 05 sample under 40mm compactionwas 175 of its mass loss under 10mm compaction (edifference in these increments was related to factors such asgradation and the particle arrangement during samplecharging It could be seen that gradation and compactionhave significant impact on the mass loss In selecting theaggregate of the bedding course for permeable roads it is

crucial to determine the gradation and the correspondingcompaction to ensure structural stability

Figure 7 also shows that the rate of mass loss differedbetween samples For example for samples with the samecompaction level of 10mm themass loss rate decreased withrising gradation (e maximum mass loss rate of the n 04and n 07 samples reached 83 gs and 005 gs respectively(e former was 166 times the latter (e mass loss rate ofsamples with the same gradation but different compactionalso varied significantly For example the maximum massloss rate of the n 05 sample with 30mm and 20mmcompaction reached 586 gs and 0054 gs respectivelywhich were two orders of magnitude apart

4 Discussion

(e permeability mass loss and mass loss rate of all sampleswere classified based on the relevant specifications of per-meable roads with the standard being 20times10minus11m2 100 g

0

5

10

15

20

25

30ln

(β)(

mndash1

)

t (s)

1020

3040

0 200 400 600 800 1000

(a)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(b)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(c)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 5 (e non-Darcy factor of samples with different gradation under different compaction levels varied with time (a) n 04 (b)n 05 (c) n 06 (d) n 07

m1m2 m3 m4 m5

Figure 6 (e lost particles collected at given time intervals

6 Advances in Civil Engineering

and 05 gs respectively Accordingly the tested samples andcompactions were categorized into three sets recommended(R) not recommended (N) and uncertain (U) (e optimalgradation and compaction levels were then derivedstatistically

It can be found from Table 3 that the permeability ofmost samples satisfied the requirements as an aggregate forpermeable road but samples with smaller gradation had a

higher mass loss during permeation which may affect thestructural stability of the bedding course For samples with amass loss less than 5 structural instability could also occurif the mass loss rate was too high (us the overall rec-ommendation was to use crushed stone with a gradation ofn 07 and adopt a compaction level of no more than 20mmin choosing crushed stone as the aggregate for the beddingcourse of permeable roads It should be noted that adhesives

0

50

100

150

200

250

300summ

i (g)

t (s)

1020

3040

0 200 400 600 800 1000

(a)

0

50

100

150

200

250

300

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(b)

0

50

100

150

200

250

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(c)

0

10

20

30

40

50

60

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 7 (e mass loss of crushed stone aggregates with different gradation (a) n 04 (b) n 05 (c) n 06 (d) n 07

Table 3 (e optimal gradation and compaction levels

Gradation andinitial compression Permeability Mass loss (e mass loss rate

04

10 R R N20 R N N30 R N N40 R N R

05

10 R N N20 U N R30 R N N40 R N N

06

10 N R R20 R N N30 R N N40 R N N

07

10 R R R20 R R R30 N U R40 N U R

Advances in Civil Engineering 7

were not used in this study (e use of adhesives will changethe permeability and particle loss of the bedding course

5 Conclusions

(e aggregate for the bedding course of permeable roadsneeds to not only meet the requirements of basic mechanicalproperties such as compressive strength and shear strengthbut also ensure permeability and structural stability (iswork analyzed permeability under extreme rainfall condi-tions and the particle mass loss during permeation and theninvestigated the stability of crushed stone aggregate andexamined the optimal gradation and compaction of thecrushed stone aggregate in engineering applications (emain conclusions are as follows

(1) (e permeation process included two phases thefirst being rapid mass loss and the second being slowpermeation (e change of permeation velocitymainly occurred in the first phase (e duration ofthe rapid mass loss phase varied for samples withdifferent gradations because of their differingamount of small particles that could migrate (epermeation velocity of samples with different gra-dations at different compaction levels showed astepwise change in its order of magnitude

(2) (roughout the permeation process the perme-ability of samples with various gradations was all atthe order of 10minus11ndash10minus10m2 (e change in perme-ability coincided with the change in flowrate mostprobably because of the sudden change of the flowaltered the permeability of the sample Factors suchas gradation compaction and the randomness ofparticles arrangement in the crushed stone duringsample charging all affected the permeability of thesample

(3) During the permeation process the mass loss de-creased with rising gradation (e mass loss of thesamples with the same gradation generally increasedwith intensifying compaction It could be seen thatgradation and compaction had strong influence onparticle mass loss (erefore ensuring the structuralstability of permeable road necessitates careful se-lection of the gradation and compaction for thecrushed stone aggregate

(4) (e permeability of most samples could satisfy therequirements as the aggregate but structural stabilityof the bedding course of the permeable road may beat stake if the sample had a high mass loss or massloss rate during permeation It is recommended touse the crushed stone sample with a gradation ofn 07 and a compaction level of no greater than20mm for the aggregate of the bedding course

Data Availability

(e data used to support the findings of this study areavailable from the author upon request

Conflicts of Interest

(e authors declare that they have no conflicts of interest

Acknowledgments

(e authors gratefully acknowledge the authors of thereferences

References

[1] S Watanabe ldquoStudy on storm water control by permeablepavement and infiltration pipesrdquo Water Science and Tech-nology vol 32 no 1 pp 25ndash32 1995

[2] W Schluter and C Jefferies ldquoModelling the outflow from aporous pavementrdquo Urban Water vol 4 no 3 pp 245ndash2532002

[3] A Benedetto ldquoA decision support system for the safety ofairport runways the case of heavy rainstormsrdquo TransportationResearch Part A Policy and Practice vol 36 no 8 pp 665ndash682 2002

[4] S Borgwardt and Y Chen ldquoStudy on long term permeabilityof permeable concrete pavement brick pavementrdquo BuildingBlock and Block Building vol 15 no 2 pp 37ndash41 2008

[5] A Beeldens L Vijverman and Y Cui ldquoExperience of usingpermeable pavement with paving brick in Belgium for 15yearsmdashpromoting application through legislationrdquo BuildingBlock and Block Building vol 23 no 1 pp 32ndash38 2016

[6] H Wang W Che and J Hu ldquoOn storm water infiltration inurban areardquo Water and Wastewater Engineering vol 27no 2 pp 4-5 2001

[7] B Wang and C Li ldquoPenetrative pavement and urban eco-logical and physical environmentrdquo Industrial Constructionvol 32 no 12 pp 29ndash31 2002

[8] B Wang ldquoApplication of penetrative pavement and itsprospectsrdquo Architecture Technology vol 33 no 9pp 659-660 2002

[9] S Wu Z Wang J Zhang J Xie and Y Wang ldquoExperimentalstudy on relationship among runoff coefficients of differentunderlying surfaces rainfall intensity and durationrdquo Journalof China Agricultural University vol 11 no 5 pp 55ndash592006

[10] Y Ding Y Huang Z Ma Z Zhong W Liu and B CaoldquoResearch of optimum mix proportion of permeable concretepacing blocks in rainwater harvesting in urban areardquo BeijingWater Resources vol 10 no 1 pp 12-13 2003

[11] N Zhang ldquoComparison and study on test methods for waterpermeability coefficients of permeable pavementrdquo Technologyof Highway and Transport vol 32 no 1 pp 6ndash9 2016

[12] W Zhang Y Ding and S Zhang ldquoStudy on water perme-ability durability of concrete permeable brickrdquo New BuildingMaterials vol 13 no 6 pp 22ndash24 2006

[13] L Hou S Feng Y Ding and S Zhang ldquoRunoff-rainfallrelationship for multilayer infiltration systems under artificialrainfallsrdquo Transactions of the Chinese Society of AgriculturalEngineering vol 22 no 9 pp 100ndash105 2006

[14] L Hou S Feng Z Han Y Ding and S Zhang ldquoExperimentalstudy on impacts of infiltration treated with porous pave-mentrdquo Journal of China Agricultural University vol 11 no 4pp 83ndash88 2006

[15] Y Meng T Li S Wang and Z Fu ldquoField survey and ap-plication analysis of infiltration performance of permeablepavements in Shanghai cityrdquo China Water and Wastewatervol 25 no 6 pp 29ndash33 2009

8 Advances in Civil Engineering

[16] L Huo Preparation Properties of Pervius Concrete PavementMaterial Southeast University Nanjing China 2004

[17] L Xu Q Li Y Wang J Huang and Y Xu ldquoAnalysis of thechanges in debris flow hazard in the context of climatechangerdquo Climate Change Research vol 16 no 4 pp 415ndash4232020

[18] J-C Chen W-S Huang and Y-F Tsai ldquoVariability in thecharacteristics of extreme rainfall events triggering debrisflows a case study in the Chenyulan watershed TaiwanrdquoNatural Hazards vol 102 no 3 pp 887ndash908 2020

[19] ASTM International ASTM C39C39M-15a Standard testmethod for compressive strength of cylindrical concrete speci-mens ASTM International West Conshohocken PA USA2015

[20] A N Talbot and F E Richart ldquo(e strength of concrete andits relation to the cement aggregate and waterrdquo BulletinUniversity of Illinois Engineering Experiment Station vol 11no 7 pp 1ndash118 1923

[21] L Wang and H Kong ldquoVariation characteristics of mass-lossrate in dynamic seepage system of the broken rocksrdquo Geo-fluids vol 2018 Article ID 7137601 17 pages 2018

[22] L Wang H Kong C Qiu and B Xu ldquoTime-varying char-acteristics on migration and loss of fine particles in fracturedmudstone under water flow scourrdquo Arabian Journal ofGeosciences vol 12 no 5 p 159 2019

[23] H Kong and L Wang ldquo(e mass loss behavior of fracturedrock in seepage process the development and application of anew seepage experimental systemrdquo Advances in Civil Engi-neering vol 2018 p 12 Article ID 7891914 2018

[24] G Lu ZWang P Liu DWang andM Oeser ldquoInvestigationof the hydraulic properties of pervious pavement mixturescharacterization of Darcy and non-Darcy flow based on poremicrostructuresrdquo Journal of Transportation Engineering PartB Pavements vol 146 no 2 Article ID 04020012 2020

[25] G Lu L Renken T Li D Wang H Li and M OeserldquoExperimental study on the polyurethane-bound perviousmixtures in the application of permeable pavementsrdquo Con-struction and Building Materials vol 202 pp 838ndash850 2019

[26] D Ma X Cai Z Zhou and X Li ldquoExperimental investigationon hydraulic properties of granular sandstone and mudstonemixturesrdquo Geofluids vol 2018 Article ID 9216578 13 pages2018

[27] L Wang H Kong Y Yin B Xu and D Zhang ldquoStrain-basednon-Darcy permeability properties in crushed rock accom-panying mass lossrdquo Arabian Journal of Geosciences vol 13no 11 p 406 2020

[28] H Kong and L Wang ldquo(e behavior of mass migration andloss in fractured rock during seepagerdquo Bulletin of EngineeringGeology and the Environment vol 79 no 2 pp 739ndash7542020

[29] L Wang Z Chen and H Kong ldquoAn experimental investi-gation for seepage-induced instability of confined brokenmudstones with consideration of mass lossrdquo Geofluidsvol 2017 Article ID 3057910 12 pages 2017

[30] L Wang H Kong and M Karakus ldquoHazard assessment ofgroundwater inrush in crushed rock mass an experimentalinvestigation of mass-loss-induced change of fluid flow be-haviorrdquo Engineering Geology vol 277 Article ID 1058122020

[31] J Wu G Han M Feng et al ldquoMass-loss effects on the flowbehavior in broken argillaceous red sandstone with differentparticle-size distributionsrdquo Comptes Rendus Mecaniquevol 347 no 6 pp 504ndash523 2019

Advances in Civil Engineering 9

gradation increased the content of fine particles decreasedAlthough some secondary small particles were producedduring the permeation process from water-rock interactionthe mass loss still mainly came from the original smallparticles (erefore the mass loss decreased with risinggradation (e n 04 sample had the highest mass loss ofabout 280 g while the n 07 sample had a maximum massloss of 48 g which was only 17 that of the n 04 sample

For samples with the same gradation the mass lossincreased with intensifying compaction For example themass loss of the n 06 sample under 40mm compaction was452 of its mass loss under 10mm compaction In contrastthe mass loss of the n 05 sample under 40mm compactionwas 175 of its mass loss under 10mm compaction (edifference in these increments was related to factors such asgradation and the particle arrangement during samplecharging It could be seen that gradation and compactionhave significant impact on the mass loss In selecting theaggregate of the bedding course for permeable roads it is

crucial to determine the gradation and the correspondingcompaction to ensure structural stability

Figure 7 also shows that the rate of mass loss differedbetween samples For example for samples with the samecompaction level of 10mm themass loss rate decreased withrising gradation (e maximum mass loss rate of the n 04and n 07 samples reached 83 gs and 005 gs respectively(e former was 166 times the latter (e mass loss rate ofsamples with the same gradation but different compactionalso varied significantly For example the maximum massloss rate of the n 05 sample with 30mm and 20mmcompaction reached 586 gs and 0054 gs respectivelywhich were two orders of magnitude apart

4 Discussion

(e permeability mass loss and mass loss rate of all sampleswere classified based on the relevant specifications of per-meable roads with the standard being 20times10minus11m2 100 g

0

5

10

15

20

25

30ln

(β)(

mndash1

)

t (s)

1020

3040

0 200 400 600 800 1000

(a)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(b)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(c)

0

5

10

15

20

25

30

ln (β

)(m

ndash1)

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 5 (e non-Darcy factor of samples with different gradation under different compaction levels varied with time (a) n 04 (b)n 05 (c) n 06 (d) n 07

m1m2 m3 m4 m5

Figure 6 (e lost particles collected at given time intervals

6 Advances in Civil Engineering

and 05 gs respectively Accordingly the tested samples andcompactions were categorized into three sets recommended(R) not recommended (N) and uncertain (U) (e optimalgradation and compaction levels were then derivedstatistically

It can be found from Table 3 that the permeability ofmost samples satisfied the requirements as an aggregate forpermeable road but samples with smaller gradation had a

higher mass loss during permeation which may affect thestructural stability of the bedding course For samples with amass loss less than 5 structural instability could also occurif the mass loss rate was too high (us the overall rec-ommendation was to use crushed stone with a gradation ofn 07 and adopt a compaction level of no more than 20mmin choosing crushed stone as the aggregate for the beddingcourse of permeable roads It should be noted that adhesives

0

50

100

150

200

250

300summ

i (g)

t (s)

1020

3040

0 200 400 600 800 1000

(a)

0

50

100

150

200

250

300

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(b)

0

50

100

150

200

250

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(c)

0

10

20

30

40

50

60

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 7 (e mass loss of crushed stone aggregates with different gradation (a) n 04 (b) n 05 (c) n 06 (d) n 07

Table 3 (e optimal gradation and compaction levels

Gradation andinitial compression Permeability Mass loss (e mass loss rate

04

10 R R N20 R N N30 R N N40 R N R

05

10 R N N20 U N R30 R N N40 R N N

06

10 N R R20 R N N30 R N N40 R N N

07

10 R R R20 R R R30 N U R40 N U R

Advances in Civil Engineering 7

were not used in this study (e use of adhesives will changethe permeability and particle loss of the bedding course

5 Conclusions

(e aggregate for the bedding course of permeable roadsneeds to not only meet the requirements of basic mechanicalproperties such as compressive strength and shear strengthbut also ensure permeability and structural stability (iswork analyzed permeability under extreme rainfall condi-tions and the particle mass loss during permeation and theninvestigated the stability of crushed stone aggregate andexamined the optimal gradation and compaction of thecrushed stone aggregate in engineering applications (emain conclusions are as follows

(1) (e permeation process included two phases thefirst being rapid mass loss and the second being slowpermeation (e change of permeation velocitymainly occurred in the first phase (e duration ofthe rapid mass loss phase varied for samples withdifferent gradations because of their differingamount of small particles that could migrate (epermeation velocity of samples with different gra-dations at different compaction levels showed astepwise change in its order of magnitude

(2) (roughout the permeation process the perme-ability of samples with various gradations was all atthe order of 10minus11ndash10minus10m2 (e change in perme-ability coincided with the change in flowrate mostprobably because of the sudden change of the flowaltered the permeability of the sample Factors suchas gradation compaction and the randomness ofparticles arrangement in the crushed stone duringsample charging all affected the permeability of thesample

(3) During the permeation process the mass loss de-creased with rising gradation (e mass loss of thesamples with the same gradation generally increasedwith intensifying compaction It could be seen thatgradation and compaction had strong influence onparticle mass loss (erefore ensuring the structuralstability of permeable road necessitates careful se-lection of the gradation and compaction for thecrushed stone aggregate

(4) (e permeability of most samples could satisfy therequirements as the aggregate but structural stabilityof the bedding course of the permeable road may beat stake if the sample had a high mass loss or massloss rate during permeation It is recommended touse the crushed stone sample with a gradation ofn 07 and a compaction level of no greater than20mm for the aggregate of the bedding course

Data Availability

(e data used to support the findings of this study areavailable from the author upon request

Conflicts of Interest

(e authors declare that they have no conflicts of interest

Acknowledgments

(e authors gratefully acknowledge the authors of thereferences

References

[1] S Watanabe ldquoStudy on storm water control by permeablepavement and infiltration pipesrdquo Water Science and Tech-nology vol 32 no 1 pp 25ndash32 1995

[2] W Schluter and C Jefferies ldquoModelling the outflow from aporous pavementrdquo Urban Water vol 4 no 3 pp 245ndash2532002

[3] A Benedetto ldquoA decision support system for the safety ofairport runways the case of heavy rainstormsrdquo TransportationResearch Part A Policy and Practice vol 36 no 8 pp 665ndash682 2002

[4] S Borgwardt and Y Chen ldquoStudy on long term permeabilityof permeable concrete pavement brick pavementrdquo BuildingBlock and Block Building vol 15 no 2 pp 37ndash41 2008

[5] A Beeldens L Vijverman and Y Cui ldquoExperience of usingpermeable pavement with paving brick in Belgium for 15yearsmdashpromoting application through legislationrdquo BuildingBlock and Block Building vol 23 no 1 pp 32ndash38 2016

[6] H Wang W Che and J Hu ldquoOn storm water infiltration inurban areardquo Water and Wastewater Engineering vol 27no 2 pp 4-5 2001

[7] B Wang and C Li ldquoPenetrative pavement and urban eco-logical and physical environmentrdquo Industrial Constructionvol 32 no 12 pp 29ndash31 2002

[8] B Wang ldquoApplication of penetrative pavement and itsprospectsrdquo Architecture Technology vol 33 no 9pp 659-660 2002

[9] S Wu Z Wang J Zhang J Xie and Y Wang ldquoExperimentalstudy on relationship among runoff coefficients of differentunderlying surfaces rainfall intensity and durationrdquo Journalof China Agricultural University vol 11 no 5 pp 55ndash592006

[10] Y Ding Y Huang Z Ma Z Zhong W Liu and B CaoldquoResearch of optimum mix proportion of permeable concretepacing blocks in rainwater harvesting in urban areardquo BeijingWater Resources vol 10 no 1 pp 12-13 2003

[11] N Zhang ldquoComparison and study on test methods for waterpermeability coefficients of permeable pavementrdquo Technologyof Highway and Transport vol 32 no 1 pp 6ndash9 2016

[12] W Zhang Y Ding and S Zhang ldquoStudy on water perme-ability durability of concrete permeable brickrdquo New BuildingMaterials vol 13 no 6 pp 22ndash24 2006

[13] L Hou S Feng Y Ding and S Zhang ldquoRunoff-rainfallrelationship for multilayer infiltration systems under artificialrainfallsrdquo Transactions of the Chinese Society of AgriculturalEngineering vol 22 no 9 pp 100ndash105 2006

[14] L Hou S Feng Z Han Y Ding and S Zhang ldquoExperimentalstudy on impacts of infiltration treated with porous pave-mentrdquo Journal of China Agricultural University vol 11 no 4pp 83ndash88 2006

[15] Y Meng T Li S Wang and Z Fu ldquoField survey and ap-plication analysis of infiltration performance of permeablepavements in Shanghai cityrdquo China Water and Wastewatervol 25 no 6 pp 29ndash33 2009

8 Advances in Civil Engineering

[16] L Huo Preparation Properties of Pervius Concrete PavementMaterial Southeast University Nanjing China 2004

[17] L Xu Q Li Y Wang J Huang and Y Xu ldquoAnalysis of thechanges in debris flow hazard in the context of climatechangerdquo Climate Change Research vol 16 no 4 pp 415ndash4232020

[18] J-C Chen W-S Huang and Y-F Tsai ldquoVariability in thecharacteristics of extreme rainfall events triggering debrisflows a case study in the Chenyulan watershed TaiwanrdquoNatural Hazards vol 102 no 3 pp 887ndash908 2020

[19] ASTM International ASTM C39C39M-15a Standard testmethod for compressive strength of cylindrical concrete speci-mens ASTM International West Conshohocken PA USA2015

[20] A N Talbot and F E Richart ldquo(e strength of concrete andits relation to the cement aggregate and waterrdquo BulletinUniversity of Illinois Engineering Experiment Station vol 11no 7 pp 1ndash118 1923

[21] L Wang and H Kong ldquoVariation characteristics of mass-lossrate in dynamic seepage system of the broken rocksrdquo Geo-fluids vol 2018 Article ID 7137601 17 pages 2018

[22] L Wang H Kong C Qiu and B Xu ldquoTime-varying char-acteristics on migration and loss of fine particles in fracturedmudstone under water flow scourrdquo Arabian Journal ofGeosciences vol 12 no 5 p 159 2019

[23] H Kong and L Wang ldquo(e mass loss behavior of fracturedrock in seepage process the development and application of anew seepage experimental systemrdquo Advances in Civil Engi-neering vol 2018 p 12 Article ID 7891914 2018

[24] G Lu ZWang P Liu DWang andM Oeser ldquoInvestigationof the hydraulic properties of pervious pavement mixturescharacterization of Darcy and non-Darcy flow based on poremicrostructuresrdquo Journal of Transportation Engineering PartB Pavements vol 146 no 2 Article ID 04020012 2020

[25] G Lu L Renken T Li D Wang H Li and M OeserldquoExperimental study on the polyurethane-bound perviousmixtures in the application of permeable pavementsrdquo Con-struction and Building Materials vol 202 pp 838ndash850 2019

[26] D Ma X Cai Z Zhou and X Li ldquoExperimental investigationon hydraulic properties of granular sandstone and mudstonemixturesrdquo Geofluids vol 2018 Article ID 9216578 13 pages2018

[27] L Wang H Kong Y Yin B Xu and D Zhang ldquoStrain-basednon-Darcy permeability properties in crushed rock accom-panying mass lossrdquo Arabian Journal of Geosciences vol 13no 11 p 406 2020

[28] H Kong and L Wang ldquo(e behavior of mass migration andloss in fractured rock during seepagerdquo Bulletin of EngineeringGeology and the Environment vol 79 no 2 pp 739ndash7542020

[29] L Wang Z Chen and H Kong ldquoAn experimental investi-gation for seepage-induced instability of confined brokenmudstones with consideration of mass lossrdquo Geofluidsvol 2017 Article ID 3057910 12 pages 2017

[30] L Wang H Kong and M Karakus ldquoHazard assessment ofgroundwater inrush in crushed rock mass an experimentalinvestigation of mass-loss-induced change of fluid flow be-haviorrdquo Engineering Geology vol 277 Article ID 1058122020

[31] J Wu G Han M Feng et al ldquoMass-loss effects on the flowbehavior in broken argillaceous red sandstone with differentparticle-size distributionsrdquo Comptes Rendus Mecaniquevol 347 no 6 pp 504ndash523 2019

Advances in Civil Engineering 9

and 05 gs respectively Accordingly the tested samples andcompactions were categorized into three sets recommended(R) not recommended (N) and uncertain (U) (e optimalgradation and compaction levels were then derivedstatistically

It can be found from Table 3 that the permeability ofmost samples satisfied the requirements as an aggregate forpermeable road but samples with smaller gradation had a

higher mass loss during permeation which may affect thestructural stability of the bedding course For samples with amass loss less than 5 structural instability could also occurif the mass loss rate was too high (us the overall rec-ommendation was to use crushed stone with a gradation ofn 07 and adopt a compaction level of no more than 20mmin choosing crushed stone as the aggregate for the beddingcourse of permeable roads It should be noted that adhesives

0

50

100

150

200

250

300summ

i (g)

t (s)

1020

3040

0 200 400 600 800 1000

(a)

0

50

100

150

200

250

300

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(b)

0

50

100

150

200

250

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(c)

0

10

20

30

40

50

60

summi (

g)

t (s)

1020

3040

0 200 400 600 800 1000

(d)

Figure 7 (e mass loss of crushed stone aggregates with different gradation (a) n 04 (b) n 05 (c) n 06 (d) n 07

Table 3 (e optimal gradation and compaction levels

Gradation andinitial compression Permeability Mass loss (e mass loss rate

04

10 R R N20 R N N30 R N N40 R N R

05

10 R N N20 U N R30 R N N40 R N N

06

10 N R R20 R N N30 R N N40 R N N

07

10 R R R20 R R R30 N U R40 N U R

Advances in Civil Engineering 7

were not used in this study (e use of adhesives will changethe permeability and particle loss of the bedding course

5 Conclusions

(e aggregate for the bedding course of permeable roadsneeds to not only meet the requirements of basic mechanicalproperties such as compressive strength and shear strengthbut also ensure permeability and structural stability (iswork analyzed permeability under extreme rainfall condi-tions and the particle mass loss during permeation and theninvestigated the stability of crushed stone aggregate andexamined the optimal gradation and compaction of thecrushed stone aggregate in engineering applications (emain conclusions are as follows

(1) (e permeation process included two phases thefirst being rapid mass loss and the second being slowpermeation (e change of permeation velocitymainly occurred in the first phase (e duration ofthe rapid mass loss phase varied for samples withdifferent gradations because of their differingamount of small particles that could migrate (epermeation velocity of samples with different gra-dations at different compaction levels showed astepwise change in its order of magnitude

(2) (roughout the permeation process the perme-ability of samples with various gradations was all atthe order of 10minus11ndash10minus10m2 (e change in perme-ability coincided with the change in flowrate mostprobably because of the sudden change of the flowaltered the permeability of the sample Factors suchas gradation compaction and the randomness ofparticles arrangement in the crushed stone duringsample charging all affected the permeability of thesample

(3) During the permeation process the mass loss de-creased with rising gradation (e mass loss of thesamples with the same gradation generally increasedwith intensifying compaction It could be seen thatgradation and compaction had strong influence onparticle mass loss (erefore ensuring the structuralstability of permeable road necessitates careful se-lection of the gradation and compaction for thecrushed stone aggregate

(4) (e permeability of most samples could satisfy therequirements as the aggregate but structural stabilityof the bedding course of the permeable road may beat stake if the sample had a high mass loss or massloss rate during permeation It is recommended touse the crushed stone sample with a gradation ofn 07 and a compaction level of no greater than20mm for the aggregate of the bedding course

Data Availability

(e data used to support the findings of this study areavailable from the author upon request

Conflicts of Interest

(e authors declare that they have no conflicts of interest

Acknowledgments

(e authors gratefully acknowledge the authors of thereferences

References

[1] S Watanabe ldquoStudy on storm water control by permeablepavement and infiltration pipesrdquo Water Science and Tech-nology vol 32 no 1 pp 25ndash32 1995

[2] W Schluter and C Jefferies ldquoModelling the outflow from aporous pavementrdquo Urban Water vol 4 no 3 pp 245ndash2532002

[3] A Benedetto ldquoA decision support system for the safety ofairport runways the case of heavy rainstormsrdquo TransportationResearch Part A Policy and Practice vol 36 no 8 pp 665ndash682 2002

[4] S Borgwardt and Y Chen ldquoStudy on long term permeabilityof permeable concrete pavement brick pavementrdquo BuildingBlock and Block Building vol 15 no 2 pp 37ndash41 2008

[5] A Beeldens L Vijverman and Y Cui ldquoExperience of usingpermeable pavement with paving brick in Belgium for 15yearsmdashpromoting application through legislationrdquo BuildingBlock and Block Building vol 23 no 1 pp 32ndash38 2016

[6] H Wang W Che and J Hu ldquoOn storm water infiltration inurban areardquo Water and Wastewater Engineering vol 27no 2 pp 4-5 2001

[7] B Wang and C Li ldquoPenetrative pavement and urban eco-logical and physical environmentrdquo Industrial Constructionvol 32 no 12 pp 29ndash31 2002

[8] B Wang ldquoApplication of penetrative pavement and itsprospectsrdquo Architecture Technology vol 33 no 9pp 659-660 2002

[9] S Wu Z Wang J Zhang J Xie and Y Wang ldquoExperimentalstudy on relationship among runoff coefficients of differentunderlying surfaces rainfall intensity and durationrdquo Journalof China Agricultural University vol 11 no 5 pp 55ndash592006

[10] Y Ding Y Huang Z Ma Z Zhong W Liu and B CaoldquoResearch of optimum mix proportion of permeable concretepacing blocks in rainwater harvesting in urban areardquo BeijingWater Resources vol 10 no 1 pp 12-13 2003

[11] N Zhang ldquoComparison and study on test methods for waterpermeability coefficients of permeable pavementrdquo Technologyof Highway and Transport vol 32 no 1 pp 6ndash9 2016

[12] W Zhang Y Ding and S Zhang ldquoStudy on water perme-ability durability of concrete permeable brickrdquo New BuildingMaterials vol 13 no 6 pp 22ndash24 2006

[13] L Hou S Feng Y Ding and S Zhang ldquoRunoff-rainfallrelationship for multilayer infiltration systems under artificialrainfallsrdquo Transactions of the Chinese Society of AgriculturalEngineering vol 22 no 9 pp 100ndash105 2006

[14] L Hou S Feng Z Han Y Ding and S Zhang ldquoExperimentalstudy on impacts of infiltration treated with porous pave-mentrdquo Journal of China Agricultural University vol 11 no 4pp 83ndash88 2006

[15] Y Meng T Li S Wang and Z Fu ldquoField survey and ap-plication analysis of infiltration performance of permeablepavements in Shanghai cityrdquo China Water and Wastewatervol 25 no 6 pp 29ndash33 2009

8 Advances in Civil Engineering

[16] L Huo Preparation Properties of Pervius Concrete PavementMaterial Southeast University Nanjing China 2004

[17] L Xu Q Li Y Wang J Huang and Y Xu ldquoAnalysis of thechanges in debris flow hazard in the context of climatechangerdquo Climate Change Research vol 16 no 4 pp 415ndash4232020

[18] J-C Chen W-S Huang and Y-F Tsai ldquoVariability in thecharacteristics of extreme rainfall events triggering debrisflows a case study in the Chenyulan watershed TaiwanrdquoNatural Hazards vol 102 no 3 pp 887ndash908 2020

[19] ASTM International ASTM C39C39M-15a Standard testmethod for compressive strength of cylindrical concrete speci-mens ASTM International West Conshohocken PA USA2015

[20] A N Talbot and F E Richart ldquo(e strength of concrete andits relation to the cement aggregate and waterrdquo BulletinUniversity of Illinois Engineering Experiment Station vol 11no 7 pp 1ndash118 1923

[21] L Wang and H Kong ldquoVariation characteristics of mass-lossrate in dynamic seepage system of the broken rocksrdquo Geo-fluids vol 2018 Article ID 7137601 17 pages 2018

[22] L Wang H Kong C Qiu and B Xu ldquoTime-varying char-acteristics on migration and loss of fine particles in fracturedmudstone under water flow scourrdquo Arabian Journal ofGeosciences vol 12 no 5 p 159 2019

[23] H Kong and L Wang ldquo(e mass loss behavior of fracturedrock in seepage process the development and application of anew seepage experimental systemrdquo Advances in Civil Engi-neering vol 2018 p 12 Article ID 7891914 2018

[24] G Lu ZWang P Liu DWang andM Oeser ldquoInvestigationof the hydraulic properties of pervious pavement mixturescharacterization of Darcy and non-Darcy flow based on poremicrostructuresrdquo Journal of Transportation Engineering PartB Pavements vol 146 no 2 Article ID 04020012 2020

[25] G Lu L Renken T Li D Wang H Li and M OeserldquoExperimental study on the polyurethane-bound perviousmixtures in the application of permeable pavementsrdquo Con-struction and Building Materials vol 202 pp 838ndash850 2019

[26] D Ma X Cai Z Zhou and X Li ldquoExperimental investigationon hydraulic properties of granular sandstone and mudstonemixturesrdquo Geofluids vol 2018 Article ID 9216578 13 pages2018

[27] L Wang H Kong Y Yin B Xu and D Zhang ldquoStrain-basednon-Darcy permeability properties in crushed rock accom-panying mass lossrdquo Arabian Journal of Geosciences vol 13no 11 p 406 2020

[28] H Kong and L Wang ldquo(e behavior of mass migration andloss in fractured rock during seepagerdquo Bulletin of EngineeringGeology and the Environment vol 79 no 2 pp 739ndash7542020

[29] L Wang Z Chen and H Kong ldquoAn experimental investi-gation for seepage-induced instability of confined brokenmudstones with consideration of mass lossrdquo Geofluidsvol 2017 Article ID 3057910 12 pages 2017

[30] L Wang H Kong and M Karakus ldquoHazard assessment ofgroundwater inrush in crushed rock mass an experimentalinvestigation of mass-loss-induced change of fluid flow be-haviorrdquo Engineering Geology vol 277 Article ID 1058122020

[31] J Wu G Han M Feng et al ldquoMass-loss effects on the flowbehavior in broken argillaceous red sandstone with differentparticle-size distributionsrdquo Comptes Rendus Mecaniquevol 347 no 6 pp 504ndash523 2019

Advances in Civil Engineering 9

were not used in this study (e use of adhesives will changethe permeability and particle loss of the bedding course

5 Conclusions

(e aggregate for the bedding course of permeable roadsneeds to not only meet the requirements of basic mechanicalproperties such as compressive strength and shear strengthbut also ensure permeability and structural stability (iswork analyzed permeability under extreme rainfall condi-tions and the particle mass loss during permeation and theninvestigated the stability of crushed stone aggregate andexamined the optimal gradation and compaction of thecrushed stone aggregate in engineering applications (emain conclusions are as follows

(1) (e permeation process included two phases thefirst being rapid mass loss and the second being slowpermeation (e change of permeation velocitymainly occurred in the first phase (e duration ofthe rapid mass loss phase varied for samples withdifferent gradations because of their differingamount of small particles that could migrate (epermeation velocity of samples with different gra-dations at different compaction levels showed astepwise change in its order of magnitude

(2) (roughout the permeation process the perme-ability of samples with various gradations was all atthe order of 10minus11ndash10minus10m2 (e change in perme-ability coincided with the change in flowrate mostprobably because of the sudden change of the flowaltered the permeability of the sample Factors suchas gradation compaction and the randomness ofparticles arrangement in the crushed stone duringsample charging all affected the permeability of thesample

(3) During the permeation process the mass loss de-creased with rising gradation (e mass loss of thesamples with the same gradation generally increasedwith intensifying compaction It could be seen thatgradation and compaction had strong influence onparticle mass loss (erefore ensuring the structuralstability of permeable road necessitates careful se-lection of the gradation and compaction for thecrushed stone aggregate

(4) (e permeability of most samples could satisfy therequirements as the aggregate but structural stabilityof the bedding course of the permeable road may beat stake if the sample had a high mass loss or massloss rate during permeation It is recommended touse the crushed stone sample with a gradation ofn 07 and a compaction level of no greater than20mm for the aggregate of the bedding course

Data Availability

(e data used to support the findings of this study areavailable from the author upon request

Conflicts of Interest

(e authors declare that they have no conflicts of interest

Acknowledgments

(e authors gratefully acknowledge the authors of thereferences

References

[1] S Watanabe ldquoStudy on storm water control by permeablepavement and infiltration pipesrdquo Water Science and Tech-nology vol 32 no 1 pp 25ndash32 1995

[2] W Schluter and C Jefferies ldquoModelling the outflow from aporous pavementrdquo Urban Water vol 4 no 3 pp 245ndash2532002

[3] A Benedetto ldquoA decision support system for the safety ofairport runways the case of heavy rainstormsrdquo TransportationResearch Part A Policy and Practice vol 36 no 8 pp 665ndash682 2002

[4] S Borgwardt and Y Chen ldquoStudy on long term permeabilityof permeable concrete pavement brick pavementrdquo BuildingBlock and Block Building vol 15 no 2 pp 37ndash41 2008

[5] A Beeldens L Vijverman and Y Cui ldquoExperience of usingpermeable pavement with paving brick in Belgium for 15yearsmdashpromoting application through legislationrdquo BuildingBlock and Block Building vol 23 no 1 pp 32ndash38 2016

[6] H Wang W Che and J Hu ldquoOn storm water infiltration inurban areardquo Water and Wastewater Engineering vol 27no 2 pp 4-5 2001

[7] B Wang and C Li ldquoPenetrative pavement and urban eco-logical and physical environmentrdquo Industrial Constructionvol 32 no 12 pp 29ndash31 2002

[8] B Wang ldquoApplication of penetrative pavement and itsprospectsrdquo Architecture Technology vol 33 no 9pp 659-660 2002

[9] S Wu Z Wang J Zhang J Xie and Y Wang ldquoExperimentalstudy on relationship among runoff coefficients of differentunderlying surfaces rainfall intensity and durationrdquo Journalof China Agricultural University vol 11 no 5 pp 55ndash592006

[10] Y Ding Y Huang Z Ma Z Zhong W Liu and B CaoldquoResearch of optimum mix proportion of permeable concretepacing blocks in rainwater harvesting in urban areardquo BeijingWater Resources vol 10 no 1 pp 12-13 2003

[11] N Zhang ldquoComparison and study on test methods for waterpermeability coefficients of permeable pavementrdquo Technologyof Highway and Transport vol 32 no 1 pp 6ndash9 2016

[12] W Zhang Y Ding and S Zhang ldquoStudy on water perme-ability durability of concrete permeable brickrdquo New BuildingMaterials vol 13 no 6 pp 22ndash24 2006

[13] L Hou S Feng Y Ding and S Zhang ldquoRunoff-rainfallrelationship for multilayer infiltration systems under artificialrainfallsrdquo Transactions of the Chinese Society of AgriculturalEngineering vol 22 no 9 pp 100ndash105 2006

[14] L Hou S Feng Z Han Y Ding and S Zhang ldquoExperimentalstudy on impacts of infiltration treated with porous pave-mentrdquo Journal of China Agricultural University vol 11 no 4pp 83ndash88 2006

[15] Y Meng T Li S Wang and Z Fu ldquoField survey and ap-plication analysis of infiltration performance of permeablepavements in Shanghai cityrdquo China Water and Wastewatervol 25 no 6 pp 29ndash33 2009

8 Advances in Civil Engineering

[16] L Huo Preparation Properties of Pervius Concrete PavementMaterial Southeast University Nanjing China 2004

[17] L Xu Q Li Y Wang J Huang and Y Xu ldquoAnalysis of thechanges in debris flow hazard in the context of climatechangerdquo Climate Change Research vol 16 no 4 pp 415ndash4232020

[18] J-C Chen W-S Huang and Y-F Tsai ldquoVariability in thecharacteristics of extreme rainfall events triggering debrisflows a case study in the Chenyulan watershed TaiwanrdquoNatural Hazards vol 102 no 3 pp 887ndash908 2020

[19] ASTM International ASTM C39C39M-15a Standard testmethod for compressive strength of cylindrical concrete speci-mens ASTM International West Conshohocken PA USA2015

[20] A N Talbot and F E Richart ldquo(e strength of concrete andits relation to the cement aggregate and waterrdquo BulletinUniversity of Illinois Engineering Experiment Station vol 11no 7 pp 1ndash118 1923

[21] L Wang and H Kong ldquoVariation characteristics of mass-lossrate in dynamic seepage system of the broken rocksrdquo Geo-fluids vol 2018 Article ID 7137601 17 pages 2018

[22] L Wang H Kong C Qiu and B Xu ldquoTime-varying char-acteristics on migration and loss of fine particles in fracturedmudstone under water flow scourrdquo Arabian Journal ofGeosciences vol 12 no 5 p 159 2019

[23] H Kong and L Wang ldquo(e mass loss behavior of fracturedrock in seepage process the development and application of anew seepage experimental systemrdquo Advances in Civil Engi-neering vol 2018 p 12 Article ID 7891914 2018

[24] G Lu ZWang P Liu DWang andM Oeser ldquoInvestigationof the hydraulic properties of pervious pavement mixturescharacterization of Darcy and non-Darcy flow based on poremicrostructuresrdquo Journal of Transportation Engineering PartB Pavements vol 146 no 2 Article ID 04020012 2020

[25] G Lu L Renken T Li D Wang H Li and M OeserldquoExperimental study on the polyurethane-bound perviousmixtures in the application of permeable pavementsrdquo Con-struction and Building Materials vol 202 pp 838ndash850 2019

[26] D Ma X Cai Z Zhou and X Li ldquoExperimental investigationon hydraulic properties of granular sandstone and mudstonemixturesrdquo Geofluids vol 2018 Article ID 9216578 13 pages2018

[27] L Wang H Kong Y Yin B Xu and D Zhang ldquoStrain-basednon-Darcy permeability properties in crushed rock accom-panying mass lossrdquo Arabian Journal of Geosciences vol 13no 11 p 406 2020

[28] H Kong and L Wang ldquo(e behavior of mass migration andloss in fractured rock during seepagerdquo Bulletin of EngineeringGeology and the Environment vol 79 no 2 pp 739ndash7542020

[29] L Wang Z Chen and H Kong ldquoAn experimental investi-gation for seepage-induced instability of confined brokenmudstones with consideration of mass lossrdquo Geofluidsvol 2017 Article ID 3057910 12 pages 2017

[30] L Wang H Kong and M Karakus ldquoHazard assessment ofgroundwater inrush in crushed rock mass an experimentalinvestigation of mass-loss-induced change of fluid flow be-haviorrdquo Engineering Geology vol 277 Article ID 1058122020

[31] J Wu G Han M Feng et al ldquoMass-loss effects on the flowbehavior in broken argillaceous red sandstone with differentparticle-size distributionsrdquo Comptes Rendus Mecaniquevol 347 no 6 pp 504ndash523 2019

Advances in Civil Engineering 9

[16] L Huo Preparation Properties of Pervius Concrete PavementMaterial Southeast University Nanjing China 2004

[17] L Xu Q Li Y Wang J Huang and Y Xu ldquoAnalysis of thechanges in debris flow hazard in the context of climatechangerdquo Climate Change Research vol 16 no 4 pp 415ndash4232020

[18] J-C Chen W-S Huang and Y-F Tsai ldquoVariability in thecharacteristics of extreme rainfall events triggering debrisflows a case study in the Chenyulan watershed TaiwanrdquoNatural Hazards vol 102 no 3 pp 887ndash908 2020

[19] ASTM International ASTM C39C39M-15a Standard testmethod for compressive strength of cylindrical concrete speci-mens ASTM International West Conshohocken PA USA2015

[20] A N Talbot and F E Richart ldquo(e strength of concrete andits relation to the cement aggregate and waterrdquo BulletinUniversity of Illinois Engineering Experiment Station vol 11no 7 pp 1ndash118 1923

[21] L Wang and H Kong ldquoVariation characteristics of mass-lossrate in dynamic seepage system of the broken rocksrdquo Geo-fluids vol 2018 Article ID 7137601 17 pages 2018

[22] L Wang H Kong C Qiu and B Xu ldquoTime-varying char-acteristics on migration and loss of fine particles in fracturedmudstone under water flow scourrdquo Arabian Journal ofGeosciences vol 12 no 5 p 159 2019

[23] H Kong and L Wang ldquo(e mass loss behavior of fracturedrock in seepage process the development and application of anew seepage experimental systemrdquo Advances in Civil Engi-neering vol 2018 p 12 Article ID 7891914 2018

[24] G Lu ZWang P Liu DWang andM Oeser ldquoInvestigationof the hydraulic properties of pervious pavement mixturescharacterization of Darcy and non-Darcy flow based on poremicrostructuresrdquo Journal of Transportation Engineering PartB Pavements vol 146 no 2 Article ID 04020012 2020

[25] G Lu L Renken T Li D Wang H Li and M OeserldquoExperimental study on the polyurethane-bound perviousmixtures in the application of permeable pavementsrdquo Con-struction and Building Materials vol 202 pp 838ndash850 2019

[26] D Ma X Cai Z Zhou and X Li ldquoExperimental investigationon hydraulic properties of granular sandstone and mudstonemixturesrdquo Geofluids vol 2018 Article ID 9216578 13 pages2018

[27] L Wang H Kong Y Yin B Xu and D Zhang ldquoStrain-basednon-Darcy permeability properties in crushed rock accom-panying mass lossrdquo Arabian Journal of Geosciences vol 13no 11 p 406 2020

[28] H Kong and L Wang ldquo(e behavior of mass migration andloss in fractured rock during seepagerdquo Bulletin of EngineeringGeology and the Environment vol 79 no 2 pp 739ndash7542020

[29] L Wang Z Chen and H Kong ldquoAn experimental investi-gation for seepage-induced instability of confined brokenmudstones with consideration of mass lossrdquo Geofluidsvol 2017 Article ID 3057910 12 pages 2017

[30] L Wang H Kong and M Karakus ldquoHazard assessment ofgroundwater inrush in crushed rock mass an experimentalinvestigation of mass-loss-induced change of fluid flow be-haviorrdquo Engineering Geology vol 277 Article ID 1058122020

[31] J Wu G Han M Feng et al ldquoMass-loss effects on the flowbehavior in broken argillaceous red sandstone with differentparticle-size distributionsrdquo Comptes Rendus Mecaniquevol 347 no 6 pp 504ndash523 2019

Advances in Civil Engineering 9