Centre for Green Concrete - Results

The Centre has developed a number of concrete solutions that can be implemented directly by the industry, both with regards to the composition of green concrete and its application. Applications focus on concrete for building purposes (mild environmental exposure class and indoor use) as well as concrete for infrastructures serving in aggressive environments.

The results of the work are described in a large number of articles, conference papers and reports, which can be downloaded from www.greenconcrete.dk. This web site also contains details of the green concrete project and the participants in the centre.

Composition of green concrete

The work covers concrete for large civil structures as well as for indoor structures. The Centre has shown that, in general, it is possible to produce green concrete for both applications that meet the normal performance requirements for traditional concrete.

• The centre has documented that some types of concrete can be produced with a reduction in CO₂emissions of 30% or more. This reduction in CO₂ emissions can be achieved by replacing relatively large quantities of the cement with fly ash, and by using cement types that require less energy to produce.
• The Centre has developed new types of concrete that reuse some of the concrete industry's own residual products, such as stone dust from the production of crushed aggregate, and concrete sludge which is a waste product from washing of concrete mixers and trucks.
• The Centre has developed new types of concrete where it is possible to reuse residual products from other industries, such as ash from the incineration of sewage sludge and biofuels.
• The Centre has helped to introduce a new type of cement with reduced impact on the environment. This is achieved by such means as using 18% renewable fuels instead of coal.

The Centre has also tested the mechanical and the fresh properties of the concrete, so that the new types of concrete can be used in practice. Moreover, tests have been carried out on the durability and the fire resistance.

Application of green concrete

The Centre has worked with various strategies for making concrete constructions more environmental friendly, including

• The use of green concrete mix designs
• Alterations in the structural design (such as bridge decks without asphalt)
• The use of various operation and maintenance strategies (stainless steel vs. traditional reinforcement).

These strategies may help to reduce the impact on the environment throughout the service life of the construction. This has been shown by lifecycle analyses.