A A PRESENTATION PRESENTATION

ONON

GREEN CONCRETEGREEN CONCRETE

Department of Civil EngineeringShri Vishnu Engineering College For

Women,Bhimavaram

Contents Contents DefinitionEnvironmental goalsFour ways to produce green concreteUse of Recycled aggregate and

crushed brick as fine aggregateUse of waste glass as a replacement

of natural sand or fine aggregateUse of quarry or stone dustUse of sludge incineration ashAdvantagesConclusion

DEFINITIONDEFINITION

Green Concrete is a term given to a concrete that has had extra steps taken in mix design that is replacement of naturally available materials in concrete with the recycled materials to ensure a sustainable structure and along life cycle with a low maintenance cost .

Environmental GoalsEnvironmental GoalsGreen Concrete is expected to fulfill the following environmental

obligations:Reduction of CO2 emissions by 21 %. Increase the use of inorganic residual products from industries

other than the concrete industry by approx. 20%. Reduce the use of fossil fuels by increasing the use of waste

derived fuels in the cement industry. The recycling capacity of the green concrete must not be less

compared to existing concrete types.The structures do not impose much harm to the environment

during their service life.

Four ways to produce green Four ways to produce green concreteconcrete

1. To increase the use of conventional residual

products, i.e. fly ash. 2. To use residual products from the concrete

industry, i.e. stone dust (from crushing of stones).3. To use residual products from other industries not

traditionally used in concrete, i.e. fly ash from bio fuels and sewage sludge incineration ash (from sewage treatment).

4. To use new types of cement with reduced environmental impact.

USE OF RECYCLED AGGREGATE AND USE OF RECYCLED AGGREGATE AND CRUSHED BRICK AS FINE CRUSHED BRICK AS FINE AGGREGATESAGGREGATES

Strength and deformation characteristics:

• The lower compressive strength recorded for concrete produced with recycled aggregate was due to higher water cement ratio.

• Concrete produced with recycled aggregates tend to have higher levels of dry shrinkage than concrete produced with natural aggregates.

• The replacement of 50% of cement with slag led to improve tensile strength for recycled aggregate concrete.

Usage of Green Concrete

Durability:

Recycled aggregate concrete has better resistance to carbonation than natural aggregate concrete.

Recycled aggregate concrete provides better resistance to freezing and then concrete produced by mixing natural aggregates.

CRUSHED BRICK

RECYCLED AGGREGATE

USE OF WASTE GLASS AS A USE OF WASTE GLASS AS A REPLACEMENT TO NATURAL SAND OR REPLACEMENT TO NATURAL SAND OR FINE AGGREGATEFINE AGGREGATE

Many of researchers reported that tensile splitting strength and flexural strength were both reduced with the presence of recycled glass sand in concrete.

Glass by nature is an impermeable material. Hence by using recycled glass sand can reduce

the permeability of concrete mix and may enhance its durability and restrict the migration of water ions inside the concrete.

A higher compressive strength is achieved A higher compressive strength is achieved when 20% of cement was replaced by glass when 20% of cement was replaced by glass

powder in concrete.powder in concrete.

CRUSHED GLASS GLASS POWDER

Use of quarry or stone dustUse of quarry or stone dust When quarry or stone dust is used in

concrete as a 100% replacement of natural sand with stone dust does not change the compressive strength of concrete or there will be improvement in the compressive strength of concrete.

There was up to 10% increase in compressive strength and flexural strength of concrete when concrete is produced by fully replacement of natural sand by crushed rock dust.

Researchers are suggested that replacement of natural sand with crushed rock dust is possible when particles of crushed rock dust are finer than 0.075 mm are 15% as fine aggregate as per codal provisions.

Use of sludge incineration ashUse of sludge incineration ash Most municipal solid waste is disposed of in land fills, a

traditional waste disposal process.

Because of lack of suitable land fill space, in many countries incineration of such waste had received widespread attention.

The ash obtained from such incineration has an average chemical composition as that of coal fly ash.

As a matter of fact, a great advantage in sustainability of concrete would be achieved if such ground ashes could actually be used in concrete production.

Sludge Incineration Ash

ADVANTAGESADVANTAGESReduced CO2 emissions.Low production costs as wastes

directly substitute the cement.Saves energy, emissions and

waste water.Helps in recycling industry

wastes.Reduces the consumption of

cement overall.

Cont…..Cont…..Better workability.Greater strength and durability than

normal concrete.Compressive strength and Flexural

behaviour is fairly equal to that of the conventional concrete.

Green concrete might solve some of the societies‘ problems with the use of inorganic, residual products which should otherwise be deposited.

ConclusionConclusionGreen concrete having reduced environmental impact

with reduction of the concrete industries co2 ±emissions by 30%.

Green concrete is having good thermal and fire resistant.

In this concrete increased concrete industry’s use of waste products by20%. Hence green concrete consumes less energy and becomes economical.

So definitely use of concrete product like green concrete in future will not only reduce the emission of co2in environment and environmental impact but also economical to produce