GREEN CONCRETE FOR THE FUTURE Mette Glavind, Project Manager, M.Sc., Ph.D. * Christian Munch-Petersen, Centre Manager, M.Sc. *

Cement and concrete may have an important role to play in enabling Denmark to fulfil its obligation, agreed at the Kyoto conference, to reduce the total CO2 emission by 20 % compared to the 1988-level before 2005. This is because approx. 1-2 % of Denmark’s total CO2 emission stems from cement and concrete production. There is considerable knowledge about how to produce concrete with a reduced environmental impact. However, it is not known to a sufficient degree- neither in Denmark nor internationally- on what scale, and with what technology, this “green ” concrete can be applied in practice in buildings and structures. For instance, there is not enough information about how the properties of green concrete, such as compressive strength, durability, fire performance, casting and execution, hardening, and curing are affected by the measures to reduce the environmental impact of concrete. This paper gives an overview of the present state of affairs in Denmark of concrete types that have reduced environmental impact, including the use of low energy cement, recycling of crushed concrete as aggregate, the use of fly ash and micro silica, etc. There is a description of among other things the possibilities of using “green ” concrete within the existing standards and specifications, and Danish and European research projects about green concrete, life cycle assessments, etc. A special focus will be on a large Danish research project running from 1998-2002, involving leading universities, institutes, building owners, contractors, consultancies, and cement and concrete manufacturers. The potential environmental benefit to society of being able to build with “green ” concrete is huge. It is realistic to assume that technology, which can halve the CO2 emission related to concrete production, can be developed. This will potentially reduce Denmark’s total CO2 emissions with -1 % and contribute significantly to achieving the targets set up at the Kyoto Conference