Its a advanced construction material .

1. POROUS CONCRETE
-PALLAVI PATIL

2. WHAT IS POROUS
CONCRETE ?
>Porousor perviousmeans, allowingwater
topassthrough.
>Concretewithhighporositythatallows
waterfromprecipitationandothersources
topassdirectlythrough.
>Thisconcretereducesthewaterrun– off
froma siteandthusallowinggroundwater
recharge.

3. WHY POROUS CONCRETE ?

4. ABOUT POROUS CEMENT
-
>It is a mixtureof cement, coarseaggregateandwithor withoutsandandhasenough
Cementouspastetocoatthecoarseaggregatewhilepreservingtheinterconnectivityof the
voids.
>Thisconcreteis beingusedas pavingmaterialtosolveor reducethestormwaterrunofftothe
drainagesystemandminimizewaterloggingproblems.
>It is animportantapplicationforsustainableconstructionandis oneof manylowimpact
developmenttechniquesusedby builderstoprotectwaterquality.

5. HOW DOES POROUS CONCRETE SOLVE THE
PROBLEM ?
>EFFICIENT STORM WATER MANAGEMENT :
i.e.,0%floodingor no standingwater.
>ENVIRONMENTAL MANAGEMENT :
1)100%infiltrationcapacityhelpstorecycleground
waterreservoir.
2)Filterrainwater, helpsreducewaterpollution.
>REDUCE COST ON STORM WATER
INFRASTRUCTURE :
100%costsaving.

7. LAYERS OF POROUS CONCRETE -

8. PLACEMENT AND CONSOLIDATION -
>Sub– basepreparationandformsshouldbedoublecheckedprior
to placement.
>Placementshouldbecontinuousandspreadingshouldberapid.
>Mechanicalvibrating, laserscreedsandmanualscreedsare
commonlyused, althoughmanualscreedscancausetearsin the
surfaceif themixtureis toostiff.
>Consolidationsis generallyaccomplishedbyrollingoverthe
concretewitha steelroller, whichcompactstheconcreteto the
heightof forms.
>Becauseof rapidhardeningandhighevaporationrates, delaysin
consolidationcancauseproblems.

9. CURING -
>As previousconcretepavementsdo notbleed, they
canhavea highpropensity forplasticshrinkage
concrete.
>Infactcuringforperviousslabsandpavements
beginsbeforetheconcreteis placed– thesub
grademustbemoistenedto preventit from
absorbingmoisturefromtheconcrete.
>Afterplacement, fogmistingfollowedbyplastic
sheetingis therecommendedcuringprocedure
andsheetingshouldremaininplaceforatleast
7days.

10. PROPERTIES -
>DENSITY–
It dependson thepropertiesandproportionsof thematerialsused, andonthecompaction
proceduresusedinplacement. inplacedensitieson theorderof 1600kg/m3to2000kg/m3are
common, whichis in theupperrangeof lightweightconcretes.
>PERMEABILITY–
It dependson thematerialsandplacingoperations. typicalflowratesforwaterthrough
perviousconcreteare 120l/m^2/ min, or 0.2cm/sto320l/m^2min, or 0.54cm/s.
>COMPRESSIVESTRENGTH–
Perviousconcretemixturescandevelopcompressivestrengthin therangeof 3.5Mpa– 28Mpa,
whichis suitableforwiderangeof applications. Typicalvaluesare about17Mpa.

11. PROPERTIES -
>FLEXURALSTRENGTH–
It generallyrangesbetweenabout1Mpaand3.8Mpa.
Factorsinfluencingflexuralstrengthare –
1. Degreeof compaction
2. Porosity
3. Theaggregate: cementratio
>SHRINKAGE–
Dryingshrinkageof perviousconcretedevelopssooner, butis muchlessthanconventionalconcrete. Roughly
50– 80 %of shrinkageoccursinfirst10days, comparedto 20 – 30%inthesameperiodforconventional
concrete.

12. HOW DOES IT WORK ?

14. APPLICATIONS
-
>PAVEMENTS
>EDGEDRAINS
>SWIMMINGPOOLDECKS
>TREESGATESINSIDEWALK
>TENNISCOURTS
>GREENHOUSEFLOORS

15. ADVANTAGES -
>Reducesrunofffromsite
>Helpsinunchanginggroundwater
>Eliminatesneedforretentionpondsandothercostlystormwatermanagementpractices
>Providesformoreefficientuseof landdevelopment
>Waterresourcesareconserved
>Adjacenttreesandvegetationare allowedmorerainwater
>Thepermeabilityof perviousconcreteprovidesincreasedsafetyfordrivers

16. DISADVANTAGES
-
>Difficultin providingthereinforcements
>Frequentmaintenanceis required
>Compressivestrengthis comparativelyless
>It requiresmoretimeandexperimentalworksfortheconstruction
>It canbeusedfortheconstructionof bridges, buildingsdamnsandso on……