Seminar Presentation Seminar Presentation onon

PERVIOUS CONCRETEPERVIOUS CONCRETE

Seminar Guide:- Seminar Guide:- Presented by:- Presented by:-Dr. V. Sarath BabuDr. V. Sarath Babu Deepak Tiwari 141539 Deepak Tiwari 141539 Devagya P. Singh 141540Devagya P. Singh 141540 Dharamveer Singh 141543Dharamveer Singh 141543

INTRODUCTION

Pervious concretePervious concrete is a special type of concrete with is a special type of concrete with a high porosity used for concrete flatwork a high porosity used for concrete flatwork applications.applications.

It allows water from precipitation and other sources to It allows water from precipitation and other sources to pass directly through, thereby reducing the runoff pass directly through, thereby reducing the runoff from a site and allowing groundwater recharge.from a site and allowing groundwater recharge.

It is also known as gap graded concrete It is also known as gap graded concrete or permeable concrete.

Pervious concrete has little or no fine aggregate.Pervious concrete has little or no fine aggregate.

It consists of 15 to 35% voids, allowing for quick drainage.

The infiltration rate of pervious concrete will fall into the range of 80 to 720 liters per minute per square meter.

Topic to be DiscussedTopic to be Discussed

IntroductionIntroductionNeed of Pervious ConcreteNeed of Pervious ConcreteComparisonComparisonMaterial Material PropertiesPropertiesApplicationApplicationAdvantagesAdvantagesDisadvantagesDisadvantagesConclusionConclusionReferenceReference

NEED OF PERVIOUS CONCRETENEED OF PERVIOUS CONCRETE

A large amount of rain water ends up falling on A large amount of rain water ends up falling on impervious surfaces such as parking lots, drive impervious surfaces such as parking lots, drive ways, sidewalks, ad streets rather than soaking ways, sidewalks, ad streets rather than soaking into the soil.into the soil.

This creates an imbalance to the natural This creates an imbalance to the natural ecosystem and leads to a host of problems ecosystem and leads to a host of problems including erosion, floods, ground water level including erosion, floods, ground water level depletion and pollution of rivers, lakes etc..depletion and pollution of rivers, lakes etc..

InsteadInstead of constructing them with conventional of constructing them with conventional concrete or asphalt, we should be switching to concrete or asphalt, we should be switching to pervious concrete or porous pavement.pervious concrete or porous pavement.

Pervious concrete also naturally filters water from Pervious concrete also naturally filters water from rainfall or storm and can reduce pollutant loads rainfall or storm and can reduce pollutant loads entering into streams, ponds and rivers.so in this entering into streams, ponds and rivers.so in this way it helps in ground water recharge.way it helps in ground water recharge.

COMPARISON OF PERVIOUS AND COMPARISON OF PERVIOUS AND IMPERVIOUS CONCRETEIMPERVIOUS CONCRETE

PERVIOUS CONCRETEPERVIOUS CONCRETE IMPERVIOUS CONCRETEIMPERVIOUS CONCRETE

MATERIALSMATERIALS

Pervious concrete mainly consists of:Pervious concrete mainly consists of: Ordinary Portland cementOrdinary Portland cement Coarse aggregate (19mm – 9.5mm)Coarse aggregate (19mm – 9.5mm) Water (Free from salts and impurities)Water (Free from salts and impurities)

In normal concrete the fine aggregates typically fills In normal concrete the fine aggregates typically fills the voids between the coarse aggregates. the voids between the coarse aggregates.

In pervious concrete fine aggregate is non-existent or In pervious concrete fine aggregate is non-existent or present in very small amounts (<10% by total weight present in very small amounts (<10% by total weight of aggregates).of aggregates).

Ranges of Materials Proportions in Pervious Ranges of Materials Proportions in Pervious ConcreteConcrete..

MATERIALMATERIAL PROPORTIONS PROPORTIONS Cementitious Cementitious materials materials

270 to 415 270 to 415 Kg/mKg/m33

Aggregate Aggregate 1190 to 1480 1190 to 1480 Kg/mKg/m33

Water: Cement ratioWater: Cement ratio(by mass) (by mass)

0.27 to 0.34 0.27 to 0.34

Aggregate: cement Aggregate: cement ratioratio(by mass) (by mass)

4 to 4.5:1 4 to 4.5:1

Fine: coarse Fine: coarse aggregate ratioaggregate ratio(by mass) (by mass)

0 to 1:1 0 to 1:1

A mix design with little water can create a very weak binder. This will create a very dry mix that is susceptible to spalling and crumbling.

Correct amount of water.

A mix design with too much water can collapse the void space, making an almost impenetrable concrete surface

Typical composition of Pervious Typical composition of Pervious ConcreteConcrete

PROPERTIES OF PERVIOUS PROPERTIES OF PERVIOUS CONCRETE:CONCRETE:

Properties of Properties of Fresh Pervious Concrete:Fresh Pervious Concrete:

The plastic pervious concrete mixture is stiff The plastic pervious concrete mixture is stiff compared to traditional concrete.compared to traditional concrete.

Slumps, when measured, are generally less than ¾ Slumps, when measured, are generally less than ¾ inches (20 mm), although slumps as high as 2 inches inches (20 mm), although slumps as high as 2 inches (50 mm) have been used.(50 mm) have been used.

However, slump of pervious concrete has no However, slump of pervious concrete has no correlation with its workability it is not be specified as correlation with its workability it is not be specified as an acceptance criterion.an acceptance criterion.

Properties of Hardened Pervious Properties of Hardened Pervious Concrete:Concrete:

Density and Porosity:Density and Porosity:

The densities are in the order of 1600 kg/mThe densities are in the order of 1600 kg/m33 to to 2000kg/m2000kg/m33. .

The void contents of the pervious concrete ranges The void contents of the pervious concrete ranges from 20 to 25%.from 20 to 25%.

Compressive Strength:Compressive Strength:

Pervious concrete mixtures can develop compressive Pervious concrete mixtures can develop compressive strengths in the range of 3.5 MPa to 28 MPa.strengths in the range of 3.5 MPa to 28 MPa.

Typical values are about 17 MPa.Typical values are about 17 MPa.

Flexural strength:Flexural strength:

Flexural strength in pervious concretes generally Flexural strength in pervious concretes generally ranges between about 1 MPa and 3.8 MPa.ranges between about 1 MPa and 3.8 MPa.

Graph Graph Compressive Strength and Days Compressive Strength and Days

Permeability:Permeability:

Typical flow rates for water through pervious Typical flow rates for water through pervious concrete are 120 L/m²/minconcrete are 120 L/m²/min

APPLICATIONS:APPLICATIONS: The various applications of pervious concrete are as The various applications of pervious concrete are as

follows:follows:

Residential roads, alleys, and drivewaysResidential roads, alleys, and driveways Low-volume pavementsLow-volume pavements Sidewalks and pathwaysSidewalks and pathways Parking areasParking areas Tennis courtsTennis courts Sub base for conventional concrete pavementsSub base for conventional concrete pavements Well liningsWell linings Swimming pool decksSwimming pool decks Noise barriers.Noise barriers.

ADVANTAGES :

Reduces runoff from site.Reduces runoff from site. Helps in unchanging ground water.Helps in unchanging ground water. Eliminates need for retention ponds & other costly Eliminates need for retention ponds & other costly

storm water management practices.storm water management practices. Provides for more efficient use of land Provides for more efficient use of land

development.development. Water resources are conservedWater resources are conserved Adjacent trees and vegetation are allowed more Adjacent trees and vegetation are allowed more

rainwater.rainwater. The permeability of pervious concrete provides The permeability of pervious concrete provides

increased safety for drivers.increased safety for drivers.

PERVIOUS CONCRETE RESIDENTIAL STREET SHOWING WATER INFILTRATION

Walkway in Beijing, China built for 2008 Olympics

Residential RoadsResidential Roads

DisadvantagesDisadvantages Difficult in providing the reinforcement Difficult in providing the reinforcement

Frequent maintenance is requiredFrequent maintenance is required

Compressive strength is comparatively lessCompressive strength is comparatively less

Require more time and experimental works for the Require more time and experimental works for the constructionconstruction

It cant be used for the construction of bridges, It cant be used for the construction of bridges, buildings, dams and so on….buildings, dams and so on….

Pervious concrete in IndiaPervious concrete in India Pervious concrete can be successfully used in India in Pervious concrete can be successfully used in India in

applications such as parking lots, driveways, applications such as parking lots, driveways, gullies/sidewalks, road platforms, etc.gullies/sidewalks, road platforms, etc.

Massive urban migration in Indian cities is causing the Massive urban migration in Indian cities is causing the ground water to go much deeper and is causing water ground water to go much deeper and is causing water shortages.shortages.

In future with increased urbanization, diminishing ground In future with increased urbanization, diminishing ground water levels and focus on sustainability, technologies water levels and focus on sustainability, technologies such as pervious concrete are likely to become even such as pervious concrete are likely to become even more popular in India as well as other countries.more popular in India as well as other countries.

ConclusionConclusion Saving in materials:- Saving in materials:- AsAs no-fines concrete no-fines concrete

contains no sand and consequently requires contains no sand and consequently requires considerably less cement per cubic yard of considerably less cement per cubic yard of concrete, there is a direct saving in materials.concrete, there is a direct saving in materials.

High thermal insulation value:High thermal insulation value:-Because of its nature, -Because of its nature, which allows the formation of large voids, it has better which allows the formation of large voids, it has better insulating characteristics than conventional concrete.insulating characteristics than conventional concrete.

Environmental Benefits:- Environmental Benefits:- Reduces storm water Reduces storm water runoffrunoff

References:References: Karthik H . Obla., “pervious concrete – an overview,” Indian Karthik H . Obla., “pervious concrete – an overview,” Indian

Concrete Journal, August 2010 pp. 9-18.Concrete Journal, August 2010 pp. 9-18.

NRMCA, “What, Why, and How? Pervious Concrete, NRMCA, “What, Why, and How? Pervious Concrete, “Concrete in practice series, CIP 38, Silver Spring, Maryland, “Concrete in practice series, CIP 38, Silver Spring, Maryland, May 2004, 2pp..May 2004, 2pp..

Pervious concrete pavements, southeast Association, Pervious concrete pavements, southeast Association, www.pervious.info

NRMCA, “Freeze Thaw Resistance of Pervious Concrete,” NRMCA, “Freeze Thaw Resistance of Pervious Concrete,” National Ready Mixed Concrete Association, May 2004.National Ready Mixed Concrete Association, May 2004.

RMC Research Foundation Pervious Concrete Research RMC Research Foundation Pervious Concrete Research Compilation: Past, Present and Future.Compilation: Past, Present and Future.

CONCRETE TECHNOLOGY TODAY, Portland Cement CONCRETE TECHNOLOGY TODAY, Portland Cement Association.Association.

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