Construction and Building Materials 101 (2015) 752–760

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Construction and Building Materials

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New achievements on positive effects of nanotechnology zyco-soilon rutting resistance and stiffness modulus of glasphalt mix

http://dx.doi.org/10.1016/j.conbuildmat.2015.10.1500950-0618/� 2015 Elsevier Ltd. All rights reserved.

⇑ Corresponding author.E-mail address: nkamboozia@civileng.iust.ac.ir (N. Kamboozia).

H. Ziari, H. Behbahani, N. Kamboozia ⇑, M. AmeriSchool of Civil Engineering, Iran University of Science and Technology (IUST), Tehran 16846-13114, Islamic Republic of Iran

h i g h l i g h t s

� N-Zy can improve the stiffness modulus of glasphalt mixtures.� N-Zy as an anti-stripping agent in glasphalt inhibit rutting performance.� SEM images shows that specific area of modified bitumen is increased.� N-Zy improves bitumen stiffness & rutting resistance of glasphalt.� N-Zy as an anti-stripping agent can improve cohesive between aggregates and glass.

a r t i c l e i n f o

Article history:Received 29 August 2015Received in revised form 17 October 2015Accepted 22 October 2015

Keywords:Waste materialsRuttingNanotechnology zyco-soilStiffness modulusGlasphalt

a b s t r a c t

On the basis of previous studies, it has been demonstrated that glass is capable of improving the behav-ioral characteristics of asphalt mixtures. The purpose of the present study is to assess the effect of nan-otechnology zycosoil on rutting resistance and stiffness modulus of glasphalt mixtures throughlaboratory experiment. For this purpose asphalt samples with two types of graining in their optimal per-centage of bitumen were subject to the dynamic tests and their mechanical properties are evaluated.Eventually, observations on the creeping behavior and stiffness modulus of the asphalt samples withtwo different graining types for the different percentages of waste crushed glass have been presented.The results of the study indicate that the samples of glasphalt modified with nanotechnology zyco-soilshow a remarkably better performance as compared to the samples of conventional asphalt.

� 2015 Elsevier Ltd. All rights reserved.

1. Introduction

1.1. Glasphalt mixture

The pavement of the roads as the surfaces which frequentlybear heavy loads should be sufficiently resistant against fatigue,fracturing, creeping and slippage [1]. In order for the mixture ofasphalt to be able to perform tasks throughout the lifespan of pave-ment layer adequately, it should be resistant against the climaticchanges and firmly withstand the constant deformations andcracks created as a result of loading and environmental factors[2]. In the recent years, the growth of the costs of repairing andreconstructing the pavement layers of the roads and airports, havemade it necessary that comprehensive studies be carried out onthe use of additives in composing asphalt mixtures to improvetheir mechanical properties against the dynamic loads. One of

the major factors influencing the tolerability of the load by theasphalt pavement is the extent of the inter-grain keying and inter-locking of aggregates. Glasphalt was first used in the model roadsto measure their resistance against the water [3]. Glasphalt wasextensively studied and researched at the turn of the 1970s andit was turned out that it’s acceptable for using in many pavementlayers. Subsequently, glasphalt was gradually abandoned becauseof the high costs of producing glass cullet [4]. Brittle glass materialswhich are crisp and fragile and rich in silicon – and are literallyreferred to as Hydrophile – show a smaller convergence in cohe-sion with asphalt. As a result, the sensitivity of these mixturesagainst water and humidity should be evaluated through relevantexperiments, and if necessary, anti-stripping substances should beused [3]. The performance of the substances used in the materialsis one of the concepts which the engineers have to deal with. Whenthe waste materials are used, their efficiency also needs to beequivalent to or greater than the common materials [5]. The sur-face of glass particles is highly smooth and a great deal of siliconis included in it and this is what makes the glass cullet particles

Table 1Gradation of aggregates of HMA layers.

Sieve number #200 #50 #8 #4 3/800

1/200 3/400

100

Sieve size (mm) 0.075 0.3 2.38 4.75 9.5 12.5 19 25.4Type of aggregation Percentage passing (%)Topeka 6 13 43 59 – 95 100 –Binder 5 12 36 50 68 – 95 100

H. Ziari et al. / Construction and Building Materials 101 (2015) 752–760 753

immensely hydrophile. In this case, pavement layer with glasphaltwould be reinforced and strengthened against damages. In order tosolve this problem, additives would be used which can prevent thestripping of the asphalt while keeping the positive characteristicsof the glass cullet in the asphalt surface. One of the materials thatcan prevent the stripping of the glasphalt surfaces is hydrated lime[6]. Based on the previous studies, it’s clear that the glasphalt mix-tures don’t show a satisfactory performance against the phe-nomenon of stripping. The phenomenon of stripping took placein some of the studies carried out in New York and Baltimore,and was taken note of in the other studies [7]. Laboratory experi-ments by Hughes in 1990 showed that stripping in glasphalt wouldnot be problematic, even though this study was confined to onetype of aggregate substances, and it was only the hydrated limethat was used as an anti-stripping additive. The chemical sub-stance of anti-stripping (usually 3–5% hydrated lime) was addedto the mixture to increase resistance against stripping [8]. Studiesindicate that using the glass cullet leads to the growth of the lifes-pan of glasphalt mixtures. In the present research, 2% of a certaintype of lime was used as an anti-stripping factor so that it couldincrease resistance against stripping [9]. One research showed thatasphalt pavements containing 10% crushed glass in glasphalt mix-tures with Topeka gradation have been observed to perform satis-factorily [10]. In 2014, researchers present the parameter functionswhich can predict visco elasto-plastic behavior of glasphalt andconventional asphalt mixture in each of the separately analyzedlevels of stress and temperature. By using these functions, it isnot necessary to carry out laboratories test for determination thepermanent strain and prediction the visco-elastoplastic behaviorof glasphalt mixture [11].

1.2. Rutting phenomenon

A good pavement layer should offer a smooth surface for driv-ing, sustain the high volume of traffic and convey the stress tothe lowermost layers with minimum dissipation [12,13]. One ofthe problems of the asphalt pavement layers is the emergence ofcreeping in them. The phenomenon of creeping means the gradualoccurrence of settlements and viable shifting without the emer-gence of cracks in the pavement layers under the constant loads.Permanent deformations which are manifestly represented as therutting of the path of wheels are seen as the first criteria for settingout the plan of asphalt pavements [14]. The quality of Hot MixAsphalt is one of the important factors which influence the effi-ciency of the flexible pavement layers. The surface rutting of thepath of wheels can lead to the endangerment of the security ofthe roads. Therefore, excessive rutting, which is seen as the mainfactor behind the immature destruction of the roads and necessi-tates the repairing and maintaining the network of the roads willlead to the decreasing of the lifespan of pavement layer service[15,16]. The deep tracks (rutting) on the path of the wheels meansa permanent deformation of the pavement layers that can increasewith time [17]. The rutting of highways is a common phenomenon,because there are numerous lanes and a high volume of daily traf-fic. In the airports, we face the phenomenon of rutting to a smalleramount because the frequency of traffic is less and there are fewerlanes of movement. Asphalt concrete, under the influence of thetraffic, is exposed to different strains [18]. The main reason forthe creation of shear strains relates to the shear stress which takesplace during the implementation in the pavement made of asphaltconcrete. When the temperature of the surface layer is high, thepossibility of the emergence of shear stress in the asphalt concretewould be greater [19]. The evaluation of the mixtures of asphaltconcrete to protect them against the phenomenon of rutting onthe path of wheels has turned into an important area of study inthe recent years. This type of damage has taken place as a result

of the consolidation and compaction of the asphalt mixture afterthe creation and implementation of plastic deformation as a resultof the passage of vehicle wheels [20,21]. The excessive use of bitu-men, aggregate, grained materials, riverbed-originated substancesand round-cornered substances are among the conventional rea-sons related to the characteristics of the substances which leavea permanent influence over the deformation of the pavement[22]. Asphalt mixture design and analysis system is based onexperiments that determine the potential of asphalt mixtures rut-ting. In AASHTO 2002 vehicles wheel path dent is estimated by theEq. (1) [23]:

eper

¼ br110k1TK2br2NK3br3 ð1Þ

where: ep: plastic strain at N load repetitions; er: elastic strain(functional characterization of mixed); N: number of load repeti-tions; T: temperature in degrees Fahrenheit; Ki: non-linear regres-sion factor; bri: parameter calibration.

1.3. Stiffness modulus

One of the important properties of asphaltic pavements is stiff-ness modulus. Bituminous mixture stiffness must be determined toevaluate both the load-induced and thermal stress and strain dis-tribution in asphalt pavements [24]. Stiffness has also been usedas an indicator of mixture quality for pavement and mixture designand to evaluate damage and age hardening trends of bituminousmixtures in both the laboratory and the field. The stiffness modu-lus is determined by use of the indirect tensile stiffness modulus(ITSM) test, repetitive tri-axial tests and sometimes repeated loaduniaxial [1]. A practical model was developed to predict the stiff-ness modulus in pavement bearing capacity analysis. This modelis a function of temperature and porosity. The general expressionfor the predictive model is given in Eq. (2):

Sm ¼ ðA1 þ A2VV ÞeT ðA3þ TÞ

A4

h ið2Þ

where Sm is the indirect tensile stiffness modulus (MPa), Vv is thevoid volume content (%), and T is the test temperature (�C). Theparameters of the expression are A1, A2, A3 and A4 [25]. Some insti-tutions, including Shell and the University of Nottingham, haveestablished prediction models for the stiffness modulus of asphaltmixtures that are used in their pavement design approaches. Thesemodels have been developed for several kinds of asphalt mixtures,except for HMAC (high modulus asphalt concrete) [26].

In this paper, nanotechnology zyco-soil was used as an anti-stripping in glasphalt mixtures and its effects on creep complianceand stiffness modulus of glasphalt mixture are investigated.

2. Experimental studies

2.1. Used materials

The aggregates used in this study were graded using the continuous type III andIV scale of the AASHTO standard [27] which is presented in Table 1. In producingthe samples, the 60–70 bitumen of the Isfahan Refinery has been used. The charac-teristics of bitumen are inserted in the Table 2.

Table 2Results of the experiments conducted on 60/70 penetration grade asphalt binder.

Test Result

Penetration (100 g, 5 s, 25 �C), 0.1 mm 64Ductility (25 �C, 5 cm/min), cm 109Softening point, �C 52Flash point, �C 261

Table 3Gradation of aggregates of glass particles used in this study.

Sieve number #4 #8 #16 #30 #50 #100 #200Sieve size (mm) 4.75 2.38 1.2 0.6 0.3 0.15 0.075Percentage passing (%) 100 63 42 27 14 9 2

Table 5Properties of the nanotechnology zyco-soil.

Properties Color Flash point Viscosity (at 25 �C)

Zyco-soil Colorless – Pale yellow 80 �C 0.2–0.8 Pa s

754 H. Ziari et al. / Construction and Building Materials 101 (2015) 752–760

Glass particles, which are used in this study, are the production of waste glass inglass artifacts. The maximum particle size of glass is 4.75 mm – in accordance withaggregation presented in Table 3 that is used in previous researches in the produc-tion of glasphalt mixtures [18]. An investigation carried out in 2004 revealed thatconsidering the limits and allowable technical properties including safety issues(skin cutting and tire puncturing), usually a maximum size of 4.75 mm can be usedas the maximum allowable glass particle dimension in pavements [28]. Also thechemical properties of glass particles used in this study are listed in Table 4. Thenanotechnology zycosoil as an anti-stripping additive is used in this research. Phys-ical properties of nanotechnology zyco-soil are given in Table 5.

2.2. Samples preparation

Nano technology zyco-soil is mixed with hot liquid asphalt and reacts with theaggregate and improves wetting and spreading power of chemically modifiedasphalt on inorganic surfaces of aggregate. In order to use full potential of nanozycosoil as an anti-stripping additive, it’s necessary to disperse these nanotechnol-ogy zycosoil aggregate in binder as much as possible. The asphalt binder-nanotech-nology zycosoil blends are mixed with a mechanical stirrer operating at a speed of4000 rpm for an overall time of 15 min to reach the required homogeneity. Withinthe mixing periods, the temperature has been set at 155 �C and kept constant byapplying an oil bath heated by a hot plate [29]. Scanning electron microscopy(SEM) images of unmodified and modified asphalt binder with nanotechnologyzycosoil is presented in Fig. 1. It can be seen from Fig. 1-b that Specific area of bitu-men modified with nano materials increases and this phenomenon can lead to thebetter adhesion between bitumen, glass cullet and aggregate.

Before preparing the samples optimal value of bitumen related to each percentof waste glass cullet has been determined by the Marshall test According to theASTM-D1559 standard. The values of 0%, 5%, 10%, 15% and 20% of waste glass culletwere used for the production of asphalt samples. Optimal value of nanotechnologyzycosoil has also been worked out through the Marshall tests on the samples ofglasphalt in an optimal value of bitumen containing different extents of glass cullet.In the present study nanotechnology zyco-soil is added in quantity equal to 3.5–5.5% of asphalt binder by weight. The Repeated Load Axial Test (RLA) and has beencarried out under the temperature 60 �C. Also Indirect tensile stiffness modulus(ITSM) test has been carried out under the temperature 5, 25 and 40 �C.

2.3. Laboratory tests

2.3.1. Rheological testsIn order to describe the effects of nanotechnology zycosoil on the asphalt binder

properties, number of rheological tests include penetration grade, softening point,ductility and rotational viscosity (RV) carried out on conventional and modifiedbitumen with different Nano content. The softening point of bitumen in the rangefrom 30 to 157 �C was determined in accordance with ASTM-D36 and ductility ofbitumen is determined according to ASTM-D113 standard. Also the penetration testwas performed according to ASTM-D5 standard. A Brookfield rotational viscometerwas used to determine the viscosity of the modified binders to evaluate the differ-ence in viscous behavior between the baseline asphalt binder and the nanocomposite-modified asphalt binder. This test was conducted at temperatures135 �C in accordance with ASTM-D4402 standard.

Table 4Chemical properties of glass particles used in this study.

Silicon oxide, % Sodium oxide, % Calcium oxide, % Magnesium oxide, %

73 15 5.55 3.6

2.3.2. Repeated Load Axial (RLA) testIn this study the permanent deformation behavior of asphalt samples is evalu-

ated. For this purpose repetitive axial loading test – the Nottingham Asphalt Test(NAT) – is performed. The Nottingham Asphalt Tester device has been used forthe conduction of non-destructive tests on the asphalt samples. This device was cre-ated in 1980 for identifying the mechanical properties of the asphalt mixturesunder dynamic loading conditions. Image of dynamic creep test equipment isshown in Fig. 2.

The Poisson’s ratio is normally taken at 0.35, which is the best value for demon-strating the behavior of the asphalt substances. This ratio is among the input data ofthe devices prior to the hardness module experiment. Repeated Load Axial Test(RLA) is used to determine the effect of different variables of asphalt mixtures onthe value of resistance to permanent deformation. In this test, permanent deforma-tion is continuously measured by two sensors. This test is performed in accordancewith Britannia Standard (BS) DD185 [30].

2.3.3. Indirect tensile stiffness modulus (ITSM) testThe stiffness modulus of HMA specimens could be measured by indirect ten-

sile stiffness modulus (ITSM) test, repetitive triaxial tests and sometimesrepeated load uniaxial. In this investigation, the ITSM test was applied to deter-mine the stiffness modulus of HMA mixtures. The test was done under adynamic load of 0.6 kN at a frequency of 0.33 Hz. The load is applied verticallyon the diametric plane of an asphalt concrete cylindrical sample. A value of 0.35for Poisson’s ratio is found to be reasonable for asphalt mixtures at about 5 �C,25 �C and 40 �C in accordance with D4123-ASTM. All of specimens are testedwith moisture conditioning (conditioned). Each specimen was tested twice byrotating it approximately 90� and repeating the same test after a two-hourrecovery period.

3. Results and discussions

3.1. Rheological Test Result

The results of rheological tests include penetration grade, soft-ening point, ductility and rotational viscosity (RV) on conventionaland modified bitumen with different nano content are shown inTable 6. It can be seen from Table 6 that addition of nano materialshas positive effect on the rheological properties of bitumen. Byaddition of nanotechnology zyco-soil to glasphalt mix the penetra-tion grade of modified bitumen and softening point of bitumen areimproved. Reduction of penetration grade by increase of nanozycosoil percent could be attributed to the high surface area, whichaltered to a rough and more reactive product for this technique.Increase the softening point is desirable, because, bitumen withhigh softening point has less temperature susceptibility andasphalt mixtures made with this bitumen are more resistanceagainst the permanent deformation and rutting at hightemperatures.

It is illustrated in Table 6 that ductility is reduced by incrementof nano particle content. In result the stiffness of modified bitumenis improved in comparison to conventional bitumen. Reducing theoily materials in maltene phase, increase viscosity and stiffness ofbitumen. It concluded from results that modified bitumen are lesssensitive to temperature changes and may also be more resistantto rutting compared to unmodified bitumen.

Aluminum oxide, % Boron oxide, % Potassium oxide, % Iron oxide, %

1.5 0.4 0.4 0.3

Fig. 1. SEM images of (a) unmodified asphalt binder with 40,000� magnification (b) modified asphalt binder with nano zycosoil with 40,000� magnification.

Fig. 2. Repeated Load Axial (RLA) test equipment.

Table 6Rheological test result for Nano modified bitumen.

Property Unmodifiedbitumen

Modifiwith 3

Penetration at 25 �C (d-mm) 64 59.1Softening point (�C) 52 58.7Rotational viscosity at 135 �C (Pa s) 2.42 2.60Ductility at 25 �C at 5 cm/min (cm) 109 101.6

Table 7Optimal value of bitumen of conventional asphalt samples and containing additivesmaterials.

No. Type of aggregation Percentage of glasscullet in terms oftotal aggregate weight

Optimal percentageof bitumen

1 Topeka – 5.52 Binder – 5.13 Topeka 5 5.34 Topeka 10 5.15 Topeka 15 5.06 Topeka 20 5.07 Binder 5 5.08 Binder 10 4.99 Binder 15 4.710 Binder 20 4.6

H. Ziari et al. / Construction and Building Materials 101 (2015) 752–760 755

3.2. Marshal test result

To scientifically and logically compare the results of the exper-iments on the simple and modified asphalt samples, the percent-age of optimal bitumen related to all sorts of mixture (includinggraining and the percentage of waste additive materials) has beenidentified using the Marshall tests and then the asphalt sampleswere produced under different circumstances with an optimalbitumen percentage. Considering the graphs of Marshall tests inthis section and the following sections, the optimal bitumen valuesfor the simple and modified asphalt samples containing the wasteadditives is presented in the Table 7.

Noting the information provided in the Table 7, it can be seenthat the value of optimal bitumen in the samples containing higher

ed bitumen.50% nano

Modified bitumenwith 4.50% nano

Modified bitumenwith 5.50% nano

57.5 56.360.1 60.92.61 2.63100.7 100.2

Fig. 3. Marshall Stability diagrams to determine the optimum percentage of nanotechnology zycosoil in asphalt samples containing waste glass cullet with Topekaaggregation.

Fig. 4. Marshall Stability diagrams to determine the optimum percentage of nanotechnology zycosoil in asphalt samples containing waste glass cullet with Binderaggregation.

756 H. Ziari et al. / Construction and Building Materials 101 (2015) 752–760

percentages of waste glass cullet decreases considerably. The Mar-shall Stability diagrams for identifying the percentage of optimalnanotechnology zycosoil in the asphalt samples containing wasteglass cullet are shown for the two graining types of Topeka andBinder in the Fig. 3 and Fig. 4. Considering the Fig. 3, it can be seenthat the growth of the percentage of nanotechnology zycosoilleaves different impacts on the glasphalt samples with differentpercentages of waste glass cullet. With the increasing of the per-centage of glass cullet, the negative impact of the smooth and pol-ished surface of the glass on the Marshall Stability increases. Onthe other hand, considering the stripping capability of the glasphaltand the growth of this problem at the same times as the growth ofthe percentage of consumed glass cullet, the need for nanotechnol-ogy zycosoil to preclude the phenomenon of stripping increases.The values of optimal nanotechnology zycosoil for the asphalt sam-ples containing waste glass cullet under the conditions of optimalbitumen for the two graining types of Topeka and Binder and thepercentage of additives has been presented in the Table 8.

3.3. RLA test result

In Fig. 5 the permanent deformations of asphaltic samples arepresented in terms of the percentage of waste glass cullet fortwo graining types of Topeka and Binder under the temperatureof 60 �C. As it can be seen in the Fig. 5, with the growth of the per-centage of glass cullet, the extent of permanent deformations inthe asphalt samples would decrease. The increase of the stiffnessmodulus is a factor which plays a role in the reduction of the defor-mations. Factors such as better grain interlocking as well as greatercoarseness resulting from the angularity of the glass cullet lead to areduction in the extent of the deformations. However, as the per-centage of glass cullet increases by a value that is greater thanthe optimal percentage, the gradual slippage of the glass culletcauses that the extent of the permanent deformations of theasphalt samples containing glass cullet rises. The variation of per-cent axial strain versus time in conventional and glasphalt sam-ples, using different percentages of waste glass cullet, with two

Table 8Optimum percentage value of nanotechnology zycosoil in glasphalt samples.

No. Type ofaggregation

Optimumpercentage ofbitumen

Percentageof glasscullet

Optimum percentageof nanotechnologyzycosoil

1 Topeka 5.3 5 3.52 Topeka 5.1 10 4.53 Topeka 5.0 15 5.54 Topeka 5.0 20 5.55 Binder 5.0 5 3.56 Binder 4.9 10 4.57 Binder 4.7 15 5.58 Binder 4.6 20 5.5

H. Ziari et al. / Construction and Building Materials 101 (2015) 752–760 757

different graining types of Topeka and Binder are shown in theFig. 6 and Fig. 7.

According to Fig. 6, it can be observed that adding glass cullet tothe asphalt samples has a great effect on the performance of thesesamples against the time-dependent deformation. It can be seenthat in addition to the largeness of the axial strain percent in the

Fig. 5. Permanent deformations versus percentage of waste gla

Fig. 6. Variations of axial strain percent versus time

conventional asphalt samples, the rate of the increase of the axialstrain in this sample is higher than the glasphalt samples. To bettercompare the creep behavior of the conventional asphalt and glas-phalt with Topeka graining, the time-dependent deformationmodel for each of the asphalt samples is provided in the Fig. 6. Itcan be seen in Fig. 6 that the rate of the increase of the axial strainin the conventional asphalt samples has experienced a 50% growthas compared to the glasphalt samples with Topeka graining and anoptimal percentage of glass cullet. Moreover, according to theFig. 7, it can be seen that the rate of the increase of axial strainin the conventional asphalt samples against the glasphalt samplewith Binder graining and an optimal percentage of glass cullethas shown a significant rise. According to Fig. 7, it can be seen thatin addition to the higher percentage of axial strain in conventionalasphalt samples, ratio of increase axial strain in this asphalt ismore than glasphalt.

Given the results of the laboratory experiments and the analysisof the results using the MATLAB 7.12.0 application, the contourplot have been presented to determine the behavior of the conven-tional and modified asphalt samples against the time-dependent

ss cullet for both Binder and Topeka aggregation at 60 �C.

in glasphalt samples with Topeka aggregation.

Fig. 7. Variations of axial strain percent versus time in glasphalt samples with Binder aggregation.

Fig. 8. Contour plot of percent axial strain (PAS) versus time (s) and glass cullet content (GCC) in asphalt samples with Topeka gradation.

758 H. Ziari et al. / Construction and Building Materials 101 (2015) 752–760

deformation. The behavior of the permanent deformationin terms of time for the asphalt samples with Topeka gradationcontaining different percentages of glass cullet are shown in theFig. 8.

Taking into consideration the Fig. 8, it can be seen that wasteglass cullet, because of multilateral angularity, high hardness and100% breakability shows a greater resistance against permanentdeformation. Moreover, the amount of optimal additive can be alsoseen in accordance with the diagram. As the percentage of wasteglass cullet reaches its optimal value, permanent deformationundergoes a sharp decline as a result of better interlocking andthe more solid pattern of the glasphalt samples.

3.4. ITSM test result

The variations in the stiffness modulus of conditioned sampleswith Topeka aggregation that include different percentages of nan-otechnology zycosoil at different temperatures are shown in Fig. 9.As it’s illustrated in Fig. 9, changes in the percentage of nanotech-

nology zycosoil content lead to considerable differences in thestiffness modulus of asphaltic samples which include waste glasscullet. Increased stiffness of bitumen due to using nano materialas an additive, is the main change that causes the stiffness modulusof waste glass cullet contained asphaltic samples to increase.According to Fig. 9, increases in temperature lead to decreases inthe stiffness modulus of glasphalt samples. The reduction trendin SM is due to temperature sensitivity of the used bitumen. Sam-ples that include 4.5% nano content at a given temperature resultedin the greatest stiffness modulus.

Fig. 10 shows 3D interpretation of stiffness modulus vs. temper-ature and nanotechnology zycosoil content in conditioned sam-ples. It can be seen that although the stiffness modulus is highlydependent upon the variation of temperature, the addition of nan-otechnology zyco-soil can improve the stiffness of asphaltic mix-tures even at high temperatures.

Variation of stiffness modulus of conditioned glasphalt at differ-ent temperature, and nanotechnology zycosoil content is showedin Eq. (3)

Fig. 9. Stiffness modulus vs. temperature in conditioned samples with Topeka aggregation.

Fig. 10. 3D interpretation of stiffness modulus vs. temperature and nano material content.

Table 9Cost-effectiveness analysis for addition of nano zycosoil in glasphalt mix.

Modified glasphalt in comparewith conventional asphalt

Parameters

More than 60% reduced Used aggregate*

Grew by about 4–5% Used nano zycosoil

H. Ziari et al. / Construction and Building Materials 101 (2015) 752–760 759

SM ðT;AÞ ¼ 1043� 12ðTÞ þ 151ðAÞ � 0:095ðT2Þ � 1:04ðT � AÞ� 6:4ðA2Þ R2 ¼ 98:5% ð3Þ

where, SM is stiffness modulus of conditioned glasphalt (MPa), T istemperature (�C), and A is Nano content (%).

More than 10% reduced Used bitumenGrew by about 10–15% Used glass culletMore than 50% reduced Energy consumption*

More than 50% reduced Asphalt production costs*

More than 50% reduced Pavement construction cost & time*

More than 50% reduced Pavement repair and maintenance costs*

Grew by about 50% Operational life

* Due to reduction of asphalt pavement thickness.

4. Cost-effectiveness analysis

Cost-effectiveness analysis (CEA) is a form of economic analysisthat compares the relative costs and outcomes (effects) of two ormore courses of action. This analysis is applied to the planningand management of many types of organized activity. Addition ofnano zycosoil can improve creep compliance and stiffness modulusof glass asphalt samples. According to this fact that in AASHTO pro-cedure resilient modulus is used for asphalt pavement design,therefore by adding nano zycosoil the calculated thickness ofasphalt pavement is decreased.

It can be seen in Table 9 that with considering the consumptionof time, energy, aggregate and bitumen, production costs of asphaltand repair and maintenance costs, the benefits of addition nanozycosoil to glasphalt mix is higher than initial cost.

760 H. Ziari et al. / Construction and Building Materials 101 (2015) 752–760

5. Conclusion

In this research, nanotechnology zycosoil was used as an anti-stripping agent in glasphalt mixtures and its effects on ruttingresistance and stiffness modulus of glasphalt mixture were inves-tigated. Main results of this research are:

� The optimal bitumen percentage related to each kind of mixture(including the type of graining and the percentage of additives)has been identified using the Marshall experiments and thenthe asphalt samples with optimal bitumen percentages werecreated under different circumstances.

� Glasphalt samples containing nanotechnology zycosoil show agrowing trend in the stiffness modulus. Factors such as graininterlock, coupled with more coarseness resulting from theangularity of the glass cullet gradually decreases thedeformations.

� It can be observed that adding nanotechnology zycosoil to glas-phalt samples has a great effect on the performance of thesesamples against the time-dependent deformation.

� It concluded from results that modified bitumen are less sensi-tive to temperature changes and may also be more resistant torutting compared to unmodified bitumen.

� With considering the consumption of time, energy, aggregateand bitumen, production costs of asphalt and repair and main-tenance costs, the benefits of addition nano zycosoil to glasphaltmix is higher than initial cost.

References

[1] Y. Huang, Pavement Analysis and Design, Prentice Hall, Englewood Cliffs, 2002.317–339.

[2] B.V. Kok, N. Kuloglu, The effects of different binders on mechanical propertiesof hot mix asphalt, Int. J. Sci. Technol. 2 (1) (2007) 41–48. Firat University,Engineering Faculty, Civil Engineering Department, Elazig, Turkiye.

[3] S. Wu, W. Yang, Y. Xue, Preparation and Properties of Glass-Asphalt Concrete,Key Laboratory for Silicate Materials Science and Engineering of Ministry ofEducation, Wuham University of Technology, Wuham, China, 2004.

[4] W.R. Malisch, D.E. Day, B.G. Wixson. Use of Domestic Waste Glass as Aggregatein Bituminous Concrete, Highway Research Record 307, Washington, D.C., USA,1975.

[5] G.W. Maupin Jr, Effect of glass concentration on stripping of glasphalt, ReportNo. VTRC-98-R30, Virginia Transportation Research Council, 1998.

[6] D.E. Day, R. Schaffer, Glasphalt Paving Handbook, University of Missouri, Rolla,1990.

[7] L. Flynn, Glasphalt utilization dependent on availability, Roads Bridges (1993)59–61.

[8] C.S. Hughes, Feasibility of using recycled glass in asphalt. Report No. VTRC 90-R3, Charlottesville, Virginia Transportation Research Council, 1990.

[9] A. Sam Noureldin, Rebecca S. McDaniel, Evaluation of surfaces mixtures of steelslag and asphalt, Transportation Research Record 1296 (1990).

[10] M. Arabani, N. Kamboozia, The linear visco-elastic behaviour of glasphaltmixture under dynamic loading conditions, Constr. Build. Mater. 41 (2013)594–601.

[11] M. Arabani, N. Kamboozia, New achievements in visco-elastoplasticconstitutive model and temperature sensitivity of glasphalt, Int. J. PavementEng. (2014). Taylor & Francis Group, published online.

[12] A.K. Haghi, M. Arabani, M. Shakeri, M. Haj-Jafari, B. Mobasher, Strengthmodification of asphalt pavement using waste tires, in: 7th InternationalFracture Conference, University of Kocaeli, Kocaeli, Turkey, 2005.

[13] A. Tarek, A. Amr, H. Mahgoub, Asphalt Crack Detection Using Thermography,University of Central Florida – Center for Advanced Transportation SystemsSimulation (CATSS) Infra Mation, 2005. Proceedings.

[14] E.R. Brown, K.Y. Foo, Comparison of unconfined and confined creep tests forhot mix asphalt, Mater. Civ. Eng. J. 6 (2) (2004).

[15] J.W. Button, D. Perdodm, R.L. Lytton, Influence of aggregate on rutting inasphalt concrete pavement, Transp. Res. Record 1259 (1999) 141–152.

[16] J.D. Brock, R. Collins, C. Lynn, Performance Related Testing with the AsphaltPavement Analyzer, Pavement Technologies Inc., Conyers, GA, USA, 2003.Technical Paper T-137.

[17] M. Wensel, A. Shalaby, M. Thiessen, V. MahB, Investigation of asphaltpavement rutting at two Canadian airfields, 4th Transportation SpecialtyConference of the Canadian Society for Civil Engineering, Montreal, Quebec,Canada (2002).

[18] A. Laurinavicius, R. Oginskas, Experimental research on the development ofrutting in asphalt concrete pavements reinforced with geosynthetic materials,Dept of Roads, Vilnius Gediminas Technical University, 2006.

[19] T.L.J. Wasage, G.P. Ong, T.F. Fwa, S.A. Tan, Laboratory evaluation of ruttingresistance of geo synthetics reinforced asphalt pavement, J. Inst. Eng.,Singapore 44 (2) (2004).

[20] J.W. Button, D. Perdomo, R.L. Lytton, Influence of aggregate on rutting inasphalt concrete pavements, Transp. Res. Record 1259 (1999) 141–152.

[21] Charles S. Hughes, Experimental Mixes to Minimize Rutting, ASCE. BostonSociety of Civil Engineers Section Journal, Boston, 2004. 931–942.

[22] J.M. Matthews, C.L. Moni smith, Effects of Aggregate Gradation on the CreepResponse of Asphalt Mixtures and Pavement Rutting Estimates, ASTM SpecialTechnical Publication, No 1147, ASTM, Philadelphia, PA, 2003. 329–343.

[23] M. Arabani, S.M. Mirabdolazimi, Evaluation of Creep Compliance of RubberizedAsphalt in Compare with Conventional Hot Mix Asphalt, in: Advanced Testingand characterization of bituminous materials, Taylor and Francis Group, 2009.

[24] A. Abbas, Simulation of the Micromechanical Behavior of Asphalt MixturesUsing the Discrete Element Method, Washington State University, Departmentof Civil and Environmental Engineering, 2004.

[25] J. Neves, A. Gomes-Correia. Evaluation of the stiffness modulus of bituminousmixtures using laboratory tests (NAT) validate by field back-analysis, 2002.

[26] L. Picado Santos, S.D. Capitão, J.C. Pais. Stiffness modulus and phase angleprediction models for high modulus asphalt concrete, 2003.

[27] AASHTO guide for design of pavement structures, 1993.[28] G.D. Airey, A.C. Collop, N.H. Thom, Mechanical performance of asphalt

mixtures incorporating slag and glass secondary aggregates, Proceeding ofthe 8th Conference On Asphalt Pavements for Southern Africa (CAPSA’04), SunCity, South Africa (2004).

[29] H. Behbahani, H. Ziari, N. Kamboozia, A. Mansour Khaki, S.M. Mirabdolazimi,Evaluation of performance and moisture sensitivity of glasphalt mixturesmodified with nanotechnology zycosoil as an anti-stripping additive, Constr.Build. Mater. 78 (2015) 60–68.

[30] British Standard Institution. Test Method for determining the creepCompliance of Asphalt Material Using the Indirect Tensile Test Device,DD185, 1995.