Pervious Concrete and its application

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Welcome to the Future in Concrete!!

ENVIR NMENT L FRIENDLYENVIR NMENT L FRIENDLYPERVIOUS CONCRETEPERVIOUS CONCRETE

Dr.Dr. ThanakornThanakorn PragyaPragya N Roy (Peter)N Roy (Peter)


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W hat is Pervious Concrete ?W hat is Pervious Concrete ?

A performanceA performance --engineered structuralengineered structuralmaterial usin the usual constituents ofmaterial usin the usual constituents of

conventional PCC, only with little or noconventional PCC, only with little or nosand in the mixture , allowing for a 15sand in the mixture , allowing for a 15--3030

percen a r vo ac or.percen a r vo ac or.

It allows 3It allows 3--8 gallons of water/min to pass8 gallons of water/min to pass.. . .. . It is an openIt is an open--cell structure with ancell structure with an

appearance sometimes described as that ofappearance sometimes described as that of

a a RiceRice KrispiesKrispies


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Pervious Concr ete Is Not a New Material :

First known use in 1852 on isle of Wright for 12 to 14 in. thick walls for homes

,

and Europe .

One British firm constructed over 250 000 homes .

Mid 1960s, experimental road in England -

- 8-in conventional concrete in conventional concrete

- 2-in pervious concrete bonded overlay in pervious concrete bonded overlay

First use for pavements in U.S. In early 1970s in Florida .

Most of the activity has been in the southeast primarily Georgia,

Florida and now Enhanced Porous Concrete pavement is in Mexico,Texas,

, , , .

California.


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GENERAL BACKGROUND OF PERVIOUSGENERAL BACKGROUND OF PERVIOUS

CONCRETECONCRETE Materials for PerviousMaterials for PerviousConcrete Production:Concrete Production:--

CementitiousCementitious material:material:-- Portland &Portland &blended cements,blended cements, flyashflyash,,pozzolanas,GGFSpozzolanas,GGFS..

Coarse aggregate:Coarse aggregate: -- 3/4in.3/4in. 1in., A/C1in., A/Cratio= 4ratio= 4 4.5 by mass.4.5 by mass.

Water :Water : water/water/cementitiouscementitious ratios =ratios =0.270.27--0.30.3

Admixtures.Admixtures.

Pervious concrete is made with a narrow aggregate gradation,but differentsur ace ex ures can e o a ne roug e use o eren max mumsizes. The concrete in the box contained a 14-in. (6.5-mm) top size, while

that below used a larger topsize, 3/4 in. (20 mm)


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Mix Proportion of Pervious Concrete:Mix Proportion of Pervious Concrete:--

Carefully controlled amounts of water &Carefully controlled amounts of water & cementitiouscementitious materials arematerials are

particles without flowing off during mixing & placing.particles without flowing off during mixing & placing.

(b) properamount of water,

(a) too little water

(c) too much water.

Samples of pervious concrete with different water contents, formed into a ball:


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Three major groups of pervious concreteThree major groups of pervious concrete..


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Pervious Concrete PavementPervious Concrete Pavement

nv ronmen a van agesnv ronmen a van ages

Percolation RechargesPercolation RechargesGroundwaterGroundwater

Water Resources are ConservedWater Resources are Conserved Less Need for IrrigationLess Need for Irrigation

areare allowed More Rainwaterallowed More Rainwater

Runoff to Streams and Lakes isRunoff to Streams and Lakes is

Cooler Surface Has Less ImpactCooler Surface Has Less Impacton Air Temperatureon Air Temperature -- Urban HeatUrban HeatIsland EffectIsland Effect


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Pervious Concrete PavementsPervious Concrete Pavements

Model Natural Ground CoverModel Natural Ground Cover

and Can be Used as Part of a Systemand Can be Used as Part of a SystemDesi ned to Meet Re uirements for: Desi ned to Meet Re uirements for:

SustainabilitySustainability

Impervious Area ZoningImpervious Area ZoningRe uirementsRe uirements


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Solution to StormwaterSolution to StormwaterManagementManagementSTORMWATER IN

PERVIOUSCONCRETE

AGGREGATE

BASE

STORMWATER OUT


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LowLow--Impact DevelopmentImpact Development P ll i n Tr m nP ll i n Tr m n Recharging GroundwaterRecharging Groundwater

LEED RequirementsLEED Requirements

Cool Communities (Urban Heat IslandCool Communities (Urban Heat IslandEffect)Effect)


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Pre-Development Post-Development Low-ImpactDevelopment


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Pollution TreatmentPollution Treatment=> Porous

About 90% of the surfaceAbout 90% of the surface Allow manymega litres ofPavement

po utants are carr e o ypo utants are carr e o y

the first the first --inch to 1inch to 1--inchinchof rainfall first flushof rainfall first flush

good freshwater tobecomecontaminated

First flush passes throughFirst flush passes through

pavement into soilpavement into soil

contaminatedby thepollutants onour streets

Soi i ters an treatsSoi i ters an treatsrainfallrainfall

and pollutecoastalwaterwaysentire parking area (insteadentire parking area (insteadof detention pond)of detention pond) Capture andcleanse the

Orc ea se ewater for ouruse?


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Rechar in Groundwater andRechar in Groundwater andAquiferAquifer


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Can pave within the drip line

Water and air filters to roots


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ReReduceduce stormwaterstormwaterrunoffrunoff

Use RecycledUse Recycled

MaterialsMaterials Use RegionalUse Regional

MaterialsMaterials

Reduce urban heatReduce urban heatislandsislands


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ypical Structure Designypical Structure Design(cross section diagram)(cross section diagram)

Pervious ConcretePervious Concrete

Compacted SubCompacted Sub--basebase(#57/#67 Stone)(#57/#67 Stone)

Filter FabricFilter Fabric

Com acted SubCom acted Sub-- raderadeumum

(92% max)(92% max)

2feetmin

i

2feetmin

i

(wet season level)(wet season level)


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BASIC INSTALLATION RECOMMENDATIONSBASIC INSTALLATION RECOMMENDATIONSfor Pervious Pavementfor Pervious Pavement

ero s ump sero s ump s Set forms with screed stripsSet forms with screed strips Use vibratory truss or rollers to spreadUse vibratory truss or rollers to spread

Compact materials with rollersCompact materials with rollers No need for troweling!No need for troweling! Joint s acin : No reater than 40Joint s acin : No reater than 40 Cure w/ plastic sheetingCure w/ plastic sheeting ==


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Fine Grading & Compacting Base.

AA--frame Vibratory Screed & Rollerframe Vibratory Screed & Rollerstrikes off and compacts the surfacestrikes off and compacts the surface

Protect & cover


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Other Applications for Porous ConcreteOther Applications for Porous Concrete

Greenhouse Floors, fish hatcheriesGreenhouse Floors, fish hatcheries Surface Course for Tennis CourtsSurface Course for Tennis Courts Basketball CourtsBasketball Courts Public walkwaysPublic walkways Swimming pool decksSwimming pool decks ParksParks Plazas and PatiosPlazas and Patios

Groins & SeawallsGroins & Seawalls e n ngse n ngs ZoosZoos Load bearing wallsLoad bearing walls


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Architectural Pervious ConcreteArchitectural Pervious ConcreteUniv. of Calif.Univ. of Calif. -- BerkeleyBerkeley

Sidewalk

Taller buildings, preservingnatural areas

Pervious gravel parking areas


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NOISE BARRIERNOISE BARRIER

Two mechanisms for noise abatement generallyTwo mechanisms for noise abatement generally

accepted:accepted: Decreased intensityDecreased intensity

at the tireat the tire pavement interface;pavement interface;andand

Dissipation of theDissipation of thegenerated as well asgenerated as well as

other incident noiseother incident noisewithin the porewithin the pore

structure of perviousstructure of perviousconcrete in the formconcrete in the form

of heat.of heat.


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Heat Island ReductionHeat Island ReductionHi h void factor and lower densitHi h void factor and lower densit less solar heat absor tion andless solar heat absor tion and

rapid cooling.rapid cooling.Lighter colour provides better reflectivity.Lighter colour provides better reflectivity.


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MAINTENANCE

Can Use Vacuum, Pressure Water, Pressure Air or Combination.

Have Been Unable to Find Anyone who Does Maintain other thanfor Normal Street

Have Been Unable to Find Anyone who Needs to Maintain

As defined by critical reduction in capacity Water runs off instead of draining through

Continuousl Informin Staff and Public

Protection Guidelines for Future Work in Area


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COSTS

Materials Cost Average 20% - 40% Higher than NormalConcrete

Due to slower discharge and loading rates

Construction is Simpler, Quicker than for Normal Concrete Larger Projects will Usually Drive Lower Unit Costs NRMCA-Certified Contractors

Benefit is to Avoid Losing Land to Retention Ponds andCreating more Runoff and Pollution


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DenverDenver Next AM Following 12 SnowNext AM Following 12 Snowtes rect y across streettes rect y across street

Photos: 5 min. differential maxPhotos: 5 min. differential max

Pervious ConcretePervious Concrete Conventional AsphaltConventional Asphalt


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CONCLUSIONCONCLUSION The use of pervious concrete is among the Best Management Practices

(BMP) recommended by the EPA and other agencies for themanagement of storm water runoff on a regional and local basis.

Eliminates the need for retention ponds, swales and other storm waterdevices.

Lowers overall project costs on a first-cost basis. Makes efficient use of land. Good for Bicycles but Bad for Skateboards .

is very sensitive to water and thus difficult to mix correctly.

Very few contractors know how to install it correctly..

Thus, we will see more applications and our expertise with porousmaterials will grow.

n ou s a s a ac c, we nee o use s ec no ogy asalmost all types of weather conditions found here.


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REFERENCES:REFERENCES:

American Concrete Institute 522R-06 on Pervious Concrete May2006 htt ://www.aciint. or /PUBS/new ubs/522.htm

National Ready Mixed Concrete Association Pervious ConcretePublicationswww.nrmca.org

Mixed Concrete Association, May 2004. www.nrmca.org

Pervious Concrete Contractor Certification, National ReadyMixed Concrete Association Au ust 2005. www.nrmca.or

City of Seattle Department of Planning and Development ClientAssistance Memo #515.htt ://www.ci.seattle.wa.us/dclu/Publications/cam/CAM515. df

LID Technical Guidance Manual for Puget Sound,http://www.psat.wa.gov/Publications/LID_tech_manual05/lid_index.

htm


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Pervious Concrete and its application