All you need to know about GREEN CONCRETE
Green Concrete is a type of concrete which has less impact on environment. CEMENT, a major constituent of the concrete which is responsible for the release of green house gas Carbon dioxide is confined to fewer amounts in green concrete replaced by its counterparts industrial wastes.
Image Source : Andy Cruxton
The concrete industry is one of two largest producers of carbon dioxide (CO2), creating up to 5% of worldwide man-made emissions of this gas, of which 50% is from the chemical process and 40% from burning fuel.The carbon dioxide CO2 produced for the manufacture of one tonne of structural concrete (using ~14% cement) is estimated at 410 kg/m3 (~180 kg/tonne @ density of 2.3 g/cm3) (reduced to 290 kg/m3 with 30% fly ash replacement of cement). The CO2 emission from the concrete production is directly proportional to the cement content used in the concrete mix; 900 kg of CO2 are emitted for the fabrication of every ton of cement, accounting for 88% of the emissions associated with the average concrete mix.Cement manufacture contributes greenhouse gases both directly through the production of carbon dioxide when calcium carbonate is thermally decomposed, producing lime and carbon dioxide,and also through the use of energy, particularly from the combustion of fossil fuels.
So, by reducing the usage of cement in concrete reduces the damage it causes to the environment.
Main Substitutes used in place of cement are :
1) FLY ASH (Fly Ash is a byproduct of Coal Combustion)
2) Blast furnace Slag
3) Recycled Glass aggregate
which are the waste products in different processes.
Advantage Of Green Concrete :
1. Optimized mix designs mean easier handling, better consistency and easier finishing.
2. Reduction in shrinkage & creep.
3. Green Concrete uses local and recycled materials in concrete.
4. The heat of hydration of green concrete is significantly lower than traditional concrete.
5. This result in a lower temperature rise in large concrete pours which is a distinct advantage for green concrete.
SUITABILITY OF GREEN CONCRETE IN STRUCTURES
Several factors which enhances the suitability of green concrete in structures include:
1. Reduce the dead weight of a structure and reduce crane age load; allow handling, lifting flexibility with lighter weight.
2. Good thermal and fire resistance, sound insulation than the traditional granite rock.
3. Improve damping resistance of building.
4. Reduction of the concrete industry's CO2-emission by 30 %.
5. Increased concrete industry's use of waste products by 20%.
6. No environmental pollution and sustainable development.
7. Green concrete requires less maintenance and repairs.
8. Compressive strength behaviour of concrete with water cement ratio is more than that of conventional concrete.
9. Flexural strength of green concrete is almost equal to that of conventional concrete.
Sources :
Wikipedia
http://www.slideshare.net/PankajKumar422/green-concrete-35268320
https://www.quora.com/What-is-green-concrete-where-it-is-used
Green Concrete is a type of concrete which has less impact on environment. CEMENT, a major constituent of the concrete which is responsible for the release of green house gas Carbon dioxide is confined to fewer amounts in green concrete replaced by its counterparts industrial wastes.
The concrete industry is one of two largest producers of carbon dioxide (CO2), creating up to 5% of worldwide man-made emissions of this gas, of which 50% is from the chemical process and 40% from burning fuel.The carbon dioxide CO2 produced for the manufacture of one tonne of structural concrete (using ~14% cement) is estimated at 410 kg/m3 (~180 kg/tonne @ density of 2.3 g/cm3) (reduced to 290 kg/m3 with 30% fly ash replacement of cement). The CO2 emission from the concrete production is directly proportional to the cement content used in the concrete mix; 900 kg of CO2 are emitted for the fabrication of every ton of cement, accounting for 88% of the emissions associated with the average concrete mix.Cement manufacture contributes greenhouse gases both directly through the production of carbon dioxide when calcium carbonate is thermally decomposed, producing lime and carbon dioxide,and also through the use of energy, particularly from the combustion of fossil fuels.
So, by reducing the usage of cement in concrete reduces the damage it causes to the environment.
Main Substitutes used in place of cement are :
1) FLY ASH (Fly Ash is a byproduct of Coal Combustion)
2) Blast furnace Slag
3) Recycled Glass aggregate
which are the waste products in different processes.
Advantage Of Green Concrete :
1. Optimized mix designs mean easier handling, better consistency and easier finishing.
2. Reduction in shrinkage & creep.
3. Green Concrete uses local and recycled materials in concrete.
4. The heat of hydration of green concrete is significantly lower than traditional concrete.
5. This result in a lower temperature rise in large concrete pours which is a distinct advantage for green concrete.
SUITABILITY OF GREEN CONCRETE IN STRUCTURES
Several factors which enhances the suitability of green concrete in structures include:
1. Reduce the dead weight of a structure and reduce crane age load; allow handling, lifting flexibility with lighter weight.
2. Good thermal and fire resistance, sound insulation than the traditional granite rock.
3. Improve damping resistance of building.
4. Reduction of the concrete industry's CO2-emission by 30 %.
5. Increased concrete industry's use of waste products by 20%.
6. No environmental pollution and sustainable development.
7. Green concrete requires less maintenance and repairs.
8. Compressive strength behaviour of concrete with water cement ratio is more than that of conventional concrete.
9. Flexural strength of green concrete is almost equal to that of conventional concrete.
Sources :
Wikipedia
http://www.slideshare.net/PankajKumar422/green-concrete-35268320
https://www.quora.com/What-is-green-concrete-where-it-is-used
Civil Scholar is a Blog by Aravind Samala on Construction, Environment, Technology, Trends and Innovation.