Carbon Emissions from Concrete
Cement production is believed to contribute annually up to 10% of carbon dioxide emissions worldwide.
Concrete is a composite material consisting mainly of aggregates, cement and water. The major part of the CO2 emission is from the production of cement. To produce Portland cement, calcination of limestone is required. This takes place at temperatures of around 1450 C. CO2 is released into the atmosphere from the calcinations of the limestone as well as from the combustion of fuels required to heat the limestone to that temperature.
Example of CO2 emission among the ingredients in the production of 1m3 ready-mixed concrete:
|
|
CO2 Emissions (kg)
|
|
Cement |
92.3 |
|
Aggregate (fine) |
2.5 |
|
Aggregate (coarse) |
2.1 |
|
Admixtures |
1.5 |
|
Water |
0.0 |
|
Transport |
2.5 |
|
TOTAL |
101.0 |
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