Concrete and CO2

                In a world that consumes annually 3571 MTm of Portland concrete; between the 7-5% of the CO₂ emissions are associated with the production of this conglomerate. Paradoxically the measures taken in the Kyoto treaty did not succeed, because of the nature of the concrete industry.

                In Europe, the emissions of CO₂ are regulated by the European Union that gives the rights to the member countries to emit stipulated tons of CO₂, and then the countries distribute these rights to the industries. The main characteristic of this system is the possibility of the industries to deal with these rights. In an  economically healthy Europe this CO₂ market worked fine, because of  the need of the industries to emit CO₂ in their production process so the price of the emission of CO₂ rose up in 2008 to 28 €/ton; an appropriate price to regulate and reduce the emissions. However when the crisis landed in the old country the production of the industries went down and the industries with CO₂ rights began to speculate with these rights and that suppose an unexpected rise of the offer of CO₂ and the consequent decrease of the  price of CO₂ emissions  which now is at 5,17€/ton.

                As a consequence of these changes in the CO₂ market, the production of Portland concrete in Europe is extremely cheap and the industry of concrete has stopped the search of new cementicious materials based on subproducts. There is a subproduct of the metallurgy industry called slag, which is commonly used in a mix with the Portland cement. However this slag can completely replace the Portland cement to constitute a warrantied cementicious material, so that can suppose a reduction of the 80-60% in the CO₂ footprint [1] compared with the Portland concrete. That is the reason why these materials are called eco-efficient. Probably if the prices of the CO₂ would come back to the values of 2008 these new materials could dominate the architecture of the European industries and buildings, for example this eco-efficient materials are used in the Nordic countries because of their low porosity.

                The relation between concrete industry and CO₂ emissions is just an example of the deficient and lack of prediction of the European emission rights of CO₂ a system that some industries use to speculate and make money and definitely does not give a solution to the emission.

[1] Alkali Activated Materials; John L.Provis, Jannie S.J. van Deventer.;Ed. Springer.