porous pavement in cold climates part 2
DESCRIPTION
Porous Pavement in Cold Climates Part 2: Costs and Performance. Robert Roseen and Thomas Ballestero, UNH Stormwater Center (presented March 17, 2011)TRANSCRIPT
Porous Pavement in Cold ClimatesPorous Pavement in Cold Climates Part: Performance and CostPart: Performance and Cost
Onondaga Environmental InstituteOnondaga Environmental Institute
17 March 201117 March 2011
Thomas Ballestero, PhD, PE, PH, CGWP, PG, Thomas Ballestero, PhD, PE, PH, CGWP, PG, Robert Roseen, PE, PhD, D.WRE, Robert Roseen, PE, PhD, D.WRE,
James Houle, CPSWQJames Houle, CPSWQ University of New Hampshire Stormwater CenterUniversity of New Hampshire Stormwater Center
Department of Civil Engineering, University of New HampshireDepartment of Civil Engineering, University of New Hampshire
OverviewOverview
1.1. Hydrology of Permeable PavementsHydrology of Permeable Pavements2.2. Water Quality PerformanceWater Quality Performance3.3. Hydraulic PerformanceHydraulic Performance4.4. Cold Climate FunctionalityCold Climate Functionality5.5. Normal MaintenanceNormal Maintenance6.6. Winter MaintenanceWinter Maintenance
22
State of the PracticeState of the Practice
Water quality performance is strong to Water quality performance is strong to excellent depending on designexcellent depending on designHydraulic performance is excellentHydraulic performance is excellentCold climate performance is strongCold climate performance is strongWinter maintenance has tremendous Winter maintenance has tremendous
potential for salt reductionpotential for salt reduction
33
Concerns On PerformanceConcerns On Performance
Little removal of nitrogenLittle removal of nitrogenNo removal of many common ionic formsNo removal of many common ionic formsHowever, a large number of installations However, a large number of installations
STILL continue to be subSTILL continue to be sub--standardstandard
44
Porous Pavement Design OverviewPorous Pavement Design Overview
Porous pavements for new and Porous pavements for new and redevelopment are a watershedredevelopment are a watershed-- based strategy that can both based strategy that can both mitigate impacts for new mitigate impacts for new development and reverse impacts development and reverse impacts in areas with redevelopment. in areas with redevelopment.
Porous pavement (PP) systems Porous pavement (PP) systems combine stormwater infiltration, combine stormwater infiltration, storage, and structural pavement storage, and structural pavement in a single system. in a single system.
PP are a layer cake system, with PP are a layer cake system, with each layer possessing structural each layer possessing structural or water quality purposes.or water quality purposes.
55
66
Porous Asphalt Path, Grey Towers National Historic Site, PA(Source: CH2M HILL)
Porous Asphalt Commercial Parking Lot, Greenland Meadows, Greenland, NH(Source: UNHSC)
Porous Asphalt Section of State Highway, South Portland, ME (Source: ME DOT)
Porous Asphalt Basketball Court, Upper Darby, PA (Source: CH2M HILL)
Porous Asphalt Residential Lane, Pelham, NH(Source: UNHSC)
Parking Lot with Standard Aisle and Porous Asphalt Stalls, Morris Arboretum, Philadelphia, PA (Source: CH2M HILL)
Typical Porous Pavement System Typical Porous Pavement System SectionsSections
77
Typical Section for Storage and Infiltration
Typical Porous Pavement Typical Porous Pavement System SectionsSystem Sections
88
Choker Course: 4”-8” (10 – 20 cm) minimum
Pervious pavement: 4-6” (10 - 15 cm) of porous asphalt
Filter Course: 8” - 12” (20 - 30 cm) minimum thickness of subbase (aka. bank run gravel or modified 304.1)
Native materials
Filter Blanket: intermediate setting bed: 3” (8 cm) thickness of 3/8” (1 cm) pea gravel
Reservoir Course: 4” (10 cm) minimum thickness of 3/4” (2 cm) crushed stone for frost protection, 4-6” (10-15 cm) diameter perforated subdrains with 2” cover
Optional-Liner for land uses where infiltration is undesirable (e.g., hazardous materials handling, sole-source aquifer protection)
Section with Filter Course for Water Quality
Water Quality Water Quality Performance ResultsPerformance Results
1010
Porous Pavements and Pond Water Porous Pavements and Pond Water QualityQuality
100
90
80
70
60
50
40
30
20
10
0
% R
emov
al E
ffici
ency
TSSTPH-D Zn DIN TP
Porous AsphaltPervious ConcreteRetention Pond
‘
TSS Removal PerformanceTSS Removal Performance
1212
1313
1414
1515
Hydrologic Hydrologic Performance ResultsPerformance Results
1717
Hydrologic Performance of Hydrologic Performance of Porous PavementsPorous Pavements
Pervious Concrete (HSGPervious Concrete (HSG--B)B)Porous Asphalt (HSGPorous Asphalt (HSG--C)C)
0
10
20
30
40
50
0 200 400 600 800 1,000Time (min)
Flow
(gpm
)
0
0.03
0.06
0.09
0.12
0.15
5-M
in P
reci
p (in
)
D-Box Flow
Effluent Flow
Precip
0.6 in depth
1818
Flow AttenuationFlow Attenuation
0
10
20
30
40
50
0 500 1,000 1,500 2,000 2,500 3,000Time (min)
Flow
(gpm
)
0
0.03
0.06
0.09
0.12
0.15
5-M
in P
reci
p (in
)
D-Box Flow
Effluent Flow
Precip
2.96 in depth
1919
Lag Time (kLag Time (kLL )) Peak Reduction (kPeak Reduction (kPP ))
55 22 11 0.50.5 0.10.1
Hydraulic PerformanceHydraulic Performance
3/23/20113/23/2011
Curve NumberCurve Number
2020
2121
RESULTSRESULTSRESULTS
2222
Method 1 Q-P
Method 3 Q p
Method 3 Q p
Tbase Tpeak Tcentroid NRCS Folmar88 7 1 1 1 2890 1 1 1 1 510 15 2 2 2 37
Method 2 Lag
MeanMedian
Standar Deviation
2323
Porous Asphalt Surface Infiltration RatesPorous Asphalt Surface Infiltration Rates
Low maintenance sensitivity due to excess infiltration capacityLow maintenance sensitivity due to excess infiltration capacity
Clogged areas can drain to adjacent unclogged areasClogged areas can drain to adjacent unclogged areas
Even with 99% clogging the IR=10 in/hr > most sands & soils
Worst case scenario, no maintenance Worst case scenario, no maintenance performed for performed for 3 yrs3 yrs
Certain areas have reduced IC (drive lanes) while parking areasCertain areas have reduced IC (drive lanes) while parking areasremain unchangedremain unchanged
New England SitesNew England Sites
2424
Infiltration Capacity by AgeInfiltration Capacity by Age
315
7,0454,013
2,598 2,905
54
2,354
140
4,365
10
100
1,000
10,000
100,000
URI-PA-02
UNH-PA-04
URI-PA-04
Grswld-PC-05
Frpt-PA-06
Sski-PA-06
SlvrLk-PA-06
StoYo-PA-06
UNH-PC-07
IC v
ia S
I tes
t (cm
/hr)
2525
How Do They Really Work?How Do They Really Work? 43 in rainfall event in 3 minutes!43 in rainfall event in 3 minutes!
Cold Climate Cold Climate Performance ResultsPerformance Results
2828
Frost PenetrationFrost Penetration
Can be related to pavement failureCan be related to pavement failure
Measured with a Measured with a ‘‘fieldfield--assembledassembled’’frost gauge frost gauge (Ricard et al., 1976)(Ricard et al., 1976)
Show relationships between Show relationships between pavements and soilspavements and soils
2929
Porous Asphalt Frost Penetration Porous Asphalt Frost Penetration
3030
Seasonal Performance EfficienciesSeasonal Performance Efficiencies
0%10%20%30%40%50%60%70%80%90%
100%
TSS TPH-D DIN Zn TP
Retention Pond
Summer
Winter
Annual
3131
Winter Maintenance & Winter Maintenance & Salt ReductionSalt Reduction
Where should reductions occur?Where should reductions occur?
Sources of Salt Loading From Vehicular Surface Deicing
(Rockingham County, NH) (NHDES 2007)
50%
3%27%
9%
11%
Parking Lots
Private Roads
Municipal Roads
State Roads
Other
3333
PA Study Area OrientationPA Study Area Orientation
3434
Measuring Skid Resistance w/ BPTMeasuring Skid Resistance w/ BPT
ASTM STANDARD E303‐93
3535
Lots oneLots one--hour after plowing, hour after plowing, --4*C (11AM on 2/3/07)4*C (11AM on 2/3/07)
PA/DMA Snow & Ice CoverPA/DMA Snow & Ice Cover
PAPA DMADMA
3636
Conditions after thawing and subsequent refreezing (9AM on 3/18/Conditions after thawing and subsequent refreezing (9AM on 3/18/07)07)
No black ice formation on PANo black ice formation on PA
PA/DMA Snow & Ice CoverPA/DMA Snow & Ice Cover
PAPA DMADMA
3737
PC Snow & Ice CoverPC Snow & Ice Cover
Conditions after thawing and subsequent refreezing (1PM on 2/16/Conditions after thawing and subsequent refreezing (1PM on 2/16/08)08)
No black ice formation on PCNo black ice formation on PC
PCPC Stnd. Asphalt Ref. LotStnd. Asphalt Ref. Lot
3838
Shading contributes to amount of cover on PCShading contributes to amount of cover on PC
PC Snow & Ice CoverPC Snow & Ice Cover
PC in sunPC in sunPC in partial PC in partial
sunsunPC in shadePC in shade
Weighted Skid Resistance (BPN)
0102030405060708090
100
100 50 25 0% Salt Application
Skid
Res
ista
nce
(BPN
)
Dense Mix AsphaltPorous Asphalt
0102030405060708090
100
100 50 25 0
% Ic
e C
ov
er
% Salt Application
% Ice Cover
Dense Mix AsphaltPorous Asphalt
Weighted Skid Resistance (BPN)
0102030405060708090
100
100 50 25 0% Salt Application
Skid
Res
ista
nce
(BPN
)
Dense Mix AsphaltPorous Asphalt
PA after spring rain on snow eventPA after spring rain on snow event
DMA after spring rain on snow eventDMA after spring rain on snow event
Effective Salt ReductionsEffective Salt Reductions
Pavement Pavement TypeType
20062006--20072007 20072007--20082008 Reductions Possible Reductions Possible when compared to when compared to
DMA with DMA with 100% App. Rate100% App. Rate
AntiAnti-- Icing Icing Apps.Apps.
Deicing Deicing Apps. Apps.
AntiAnti-- Icing Icing Apps.Apps.
Deicing Deicing Apps. Apps. App. App.
RateRate
Average Average Mass Mass
Reduction*Reduction*((’’0606--’’08)08)
DMA DMA 1515 1414 2323 2222 100%100% 0%0%PAPA 1515 66 2323 2727 25%25% 75%75%
PC PC -- shadeshade -- -- 2323 3131 100%100% --20%20%
PC PC -- sunsun -- -- 2323 2323 100%100% --2%2%
** Reduction possible with no loss in skid resistance (safety)Reduction possible with no loss in skid resistance (safety)
Winter Maintenance GuidanceWinter Maintenance Guidance
Salt reduction potential will be site specific and vary Salt reduction potential will be site specific and vary depending on shading and climate. depending on shading and climate.
Plow after every storm. Plow after every storm.
Apply antiApply anti--icing treatments prior to storms. Antiicing treatments prior to storms. Anti--icing icing has the potential to provide the benefit of increased has the potential to provide the benefit of increased traffic safety at the lowest cost and with less traffic safety at the lowest cost and with less environmental impact. environmental impact.
Deicing is NOT required for black ice development. Deicing is NOT required for black ice development.
Apply deicing treatments during, and after storms as Apply deicing treatments during, and after storms as necessary to control compact snow and ice not necessary to control compact snow and ice not removed by plowing. Excess may be required.removed by plowing. Excess may be required.
4141
Winter Maintenance GuidanceWinter Maintenance Guidance
Mixed precipitation and compact snow or ice is Mixed precipitation and compact snow or ice is particularly problematic for porous surfaces. This is particularly problematic for porous surfaces. This is prevented by appropriate plowing and corrected by prevented by appropriate plowing and corrected by application of excess deicing chemicals.application of excess deicing chemicals.
In certain instances of compact snow and ice, In certain instances of compact snow and ice, excess salt may be required, however loading is excess salt may be required, however loading is offset by the overall reduced salt during routine offset by the overall reduced salt during routine winter maintenance and salt reduction.winter maintenance and salt reduction.
With good sun exposure some porous asphalt With good sun exposure some porous asphalt installations will require no deicing. installations will require no deicing.
Porous asphalt provides exceptional treatment for Porous asphalt provides exceptional treatment for rain on snow events which commonly result in rain on snow events which commonly result in dangerous refreezingdangerous refreezing
4242
Future Research NeededFuture Research Needed
Additional research is needed to examine Additional research is needed to examine salting loading at high loading rates salting loading at high loading rates common to commercial applicationscommon to commercial applicationsMN Recommended application rates of MN Recommended application rates of
3lbs per 1000 square feet appear to be 3lbs per 1000 square feet appear to be exceptionally low in comparison to exceptionally low in comparison to commercial rates.commercial rates.Salt substitutes: water, viscous brineSalt substitutes: water, viscous brine
4343
4444
Post Construction O&M Post Construction O&M
Curing time needs are site specific but there should be at least 24-48 hrs of curing. Common sense clause may lead to lower threshold for small jobs with lighter loading such as when pavement surface is less than 100 F (one- time measurement). Problems occur when the surface temperature is greater than 120 F.
Cost of Porous MaterialsCost of Porous Materials
4545
4646
Cost InformationCost Information~10-20% more for materials 2009, DMA $75-100/ton, PA $89-125/ton placed
by machine for parking and residential road and driveways
Complicated jobs with handwork are more expensive
DMA $2.25/sf, PA $2.80/sf, not including subbase
Costs offset by lack of stormwater infrastructureCost break even is achieved when designing for
quantity management ~Q10-Q25
MaintenanceMaintenance
4747
PrePre--Tx Extent of Debris/CloggingTx Extent of Debris/Clogging
Infiltration capacity via the PreInfiltration capacity via the Pre--Tx DRI test varied from 0 to 53 Tx DRI test varied from 0 to 53 cm/hr, all effectively clogged when slope is considered.cm/hr, all effectively clogged when slope is considered.
4848
PrePre--Tx Tx Infiltration at Infiltration at
Grid LocationsGrid Locations
01,0002,0003,0004,0005,0006,0007,0008,0009,000
D E J G Q H A I F V S N K M W P L U R O B T CTest Location
IC v
ia S
I Tes
t (cm
/hr)
4949
Treatment Effectiveness for Clogged Treatment Effectiveness for Clogged LocationsLocations
0
50
100
150
200
250
300
PW & Vac Soap, PW, & VacCleaning Treatment
Mea
n IC
(cm
/hr)
Pre-Tx ICPost-Tx IC
5050
Pervious Concrete SpallingPervious Concrete Spalling
5151
5252
5353
5454
5555
5656
5757
5858
Boulder Hills, Pelham, NHBoulder Hills, Pelham, NH
2009 Installation of 9002009 Installation of 900’’ of of first PA private residential first PA private residential road in Northeastroad in Northeast
Site will be nearly Zero Site will be nearly Zero dischargedischarge
LID subdivision 55+ Active LID subdivision 55+ Active Adult CommunityAdult Community
Large sand depositLarge sand deposit
Cost 25% greater per ton Cost 25% greater per ton installedinstalled
3/23/20113/23/2011 5959
But there is moreBut there is more……
Salted twice, then never again (less salt to receiving Salted twice, then never again (less salt to receiving stream)stream)
Better traction than standard DMABetter traction than standard DMA Fire fighting storage from rooftop captureFire fighting storage from rooftop capture No concern about mosquitoes in the pondsNo concern about mosquitoes in the ponds
Very little site runoff (pollutant load to stream very Very little site runoff (pollutant load to stream very
small, no thermal pollution)small, no thermal pollution) Receiving stream geomorphic equilibrium not taxedReceiving stream geomorphic equilibrium not taxed
The project sold 2 units in 2009, and 11 units since The project sold 2 units in 2009, and 11 units since
January 2010January 2010……much easier to sell GREENmuch easier to sell GREEN
6060
Questions?Questions?