|
 |
 |
| ENVIRONMENTAL IMPACT |
| statistics |
 |
Cement
- Global production of cement
in 2000 was 1.56 billion tones. One third of this was produced
in China alone. (Source: USGS Minerals Information. Cement Statistics
2000)
- In manufacturing 1.56 billion tonnes of portland
cement each year worldwide, an equivalent amount of CO2
is released into the air.
Making
one tonne of cement:
- requires
about 2 tonnes of raw material (limestone and shale)
- consumes
about 4 GJ of energy in electricity, process heat, and transport
(the energy equivalent to 131 cubic metres of natural gas)
- produces approximately one tonne of CO2
- produces about 3 kg of NOX, an air contaminant
that contributes to ground-level smog
- produces about 0.4 kg of PM10 - an airborne particulate
matter that is harmful to the respiratory tract when inhaled
- The manufacturing of cement accounts for 5% of
the non-energy related greenhouse gas emissions in Canada (Source:
Canada's Second Report on Climate Change. Environment Canada,
1997)
Concrete
- Annual global production of concrete is
about 5 billion cubic yards. (Source: Cement Association of Canada)
- Twice as much concrete is used in construction
around the world than the total of all other building materials,
including wood, steel, plastic and aluminum. (Source: Cement Association
of Canada)
Supplementary Cementing
Materials
- The annual production of fly ash in North America
is 60 million tonnes. (Source: M. Malhotra "Making Concrete
Greener with Fly Ash" May 1999, Concrete International)
- The annual production of fly ash in Canada in
1999 was 5.1 million tonnes; 85% of the fly ash produced ended
up in landfills. (Source: NRCAN-CANMET)
- An estimated 600 million tonnes of fly ash was
produced in the world in 2000.(Source: Concrete International
May 1999 - M. Malhotra "Making Concrete Greener with Fly
Ash")
- Lafarge Canada, a major Canadian concrete manufacturer,
estimates 25% of the cement in the average concrete mix is replaced
by fly ash in the Vancouver region.
|
|
|
 |
 |
|
concrete use
twice as
much concrete is used in construction around the world than the
total of all other building materials, including wood, steel, plastic
and aluminum
|
|