The cement industry, however, contributes approximately 7% of global CO2 emissions.
Surely the answer is to use less cement?
To put things into perspective, 1 tonne of cement production emits approximately 0.83t of CO2 into the atmosphere.
The 10 year life span of an average family saloon car, travelling 150,000 miles (240,000 km) will emit approximately 40.8t of CO2.
This is the equivalent embedded CO2 footprint of a 110m3 pour of C32/40 concrete.
Surely one of the simplest ways to reduce CO2 emissions is better and more selective concrete mix designs, utilising not only cement replacements, such as PFA and GGBFS, but also ultra fine fillers and powerful modern day superplasticisers to counteract the slow strength gain of blended materials and accelerate construction cycles.
Another major step forward would be a massive downward revision of the very high minimum cement requirements contained in current British and European standards and codes of practice.
CHARLES ALLEN, managing director, OtB Engineering, Unit 4 La Gare, 51-55 Surrey Row, London SE1 0BZ.