Arbejdsrapport fra Miljøstyrelsen, 2/2004 – Produktområdeprojekt vedrørende betonprodukter - handlingsplan

Focus Area Project: "Concrete" - Action Plan

Summary and conclusions

The Danish Environmental Protection Agency has appointed concrete products to be a focus area. The Danish EPA wishes to focus on the possibilities of reducing the environmental impact from the construction industry by solving some of the main environmental problems when using concrete.

The present report presents phase 1 of the project "Project on the focus area concrete products" and is a proposal for a plan of action concerning the continuation of the project.

The plan of action was prepared by the Danish Technological Institute together with Betonindustriens Fællesråd and Aalborg Portland A/S during January-September 2003.

The preparation of the plan of action was based on the principles of LFA (Logical Framework Approach), and the following results were achieved:

Analysis of the interested parties

All parties interested in the life cycle of a concrete product were identified and asked to participate actively in the preparation of the plan of action. The parties in question are listed in the table below.

Production of raw materials	Production of concrete	Construction	Service and maintenance	Demolition and disposal
Aalborg Portland E-mineral Fosroc Foreningen af Sten- og Grusindustrier Foreningen af Danske Ral- og Sandsugere Skov- og Naturstyrelsen Optiroc	Fabriksbeton-foreningen – Teknisk udvalg Betonelement-foreningen – Teknisk udvalg Fabriksbeton-foreningen - Teknisk udvalg	Dansk Byggeri Foreningen af rådgivende ingeniører F.R.I. Entreprenører (NCC)	Vejdirektoratet Bygherreforeningen	RGS 90 Concrete Plant Technology Dansk Byggeris Nedbrydersektion Dansk Byggeri – Miljøsektionen

Trouble shooting

All the phases of the life cycle of a concrete product were reviewed and assessed. The main environmental impacts from concrete products are caused by:

the use of alloy steel for reinforcement
substantial energy consumption for clinkers and reinforcement, and demolition and recycling of construction materials
substantial energy consumption for drying-out and heating in the construction phase
leaching of hydrocarbons from concrete and concrete slurry as well as heavy metals from residual products
indoor climate and matters concerning the working environment when using and demolishing buildings
matters concerning health and environment when using surface treated products

Prioritisation of the proposals

The working group of the project worked out the proposals, whichwere then discussed in a workshop where the interested parties and the steering committee participated.

Among the focus areas identified in the trouble shooting it was decided to leave out the following areas:

matters concerning reinforcement – as alloy steel is only used in a small scale, and as the reduction of the environmental impact caused during the manufacturing of reinforcement is not within the scope of the project
matters concerning the manufacture of concrete – which is not within the scope of the project
matters concerning occupational health during demolition, as the main issues addressed in the present project concerns environmental matters.

In general, much attention was given to the importance of presenting the results of the project to a large number of people within the construction industry.

The project on hydrocarbons in concrete slurry is an area that is highly prioritised. Phase 1 concerning this issue has already been initiated. The purpose of the phase is to identify what causes the hydrocarbons in concrete slurry, and how the amount of hydrocarbons can be reduced.

The projects with top priority are:

A project on hydrocarbons (phase 2). The purpose of the project is to identify the leaching of hydrocarbons and suggest limit values. The budget of the project is 440,000 DKK, and it can be finished within nine months.
A project on using demolished concrete as aggregate. The purpose of the project is to reduce the use of coarse aggregate and give the manufacturers a possibility to use their own waste. The budget of the project is 600,000 DKK, and it can be finished within 10 months.
A project on concrete and indoor climate. The purpose of the project is to clarify the negative as well as the positive effects of concrete on the indoor climate in buildings. The budget of the project is 600,000 DKK, and it can be finished within 12 months.
A leaflet with the purpose of presenting specific information on concrete and the environment. The budget of the project is 200,000 DKK, and it can be finished within three months.
Drying-out of concrete. The purpose of the project is to obtain a 50 percent reduction of the energy used for drying-out in the construction phase. The budget of the project is 1,000,000 DKK, and it can be finished within 18 months.
Leaching of heavy metals. The purpose of the project is to clarify the extent and the impact of the leaching of heavy metals from fly ashes and other residues that are used in concrete. The budget of the project is 500,000 DKK, and it can be finished within 10 months.

In the long run the construction industry wishes to contribute to the reduction in the use of hazardous substances in materials used for surface treatment of concrete. At the workshop the participants expressed their interest in developing tools to help the industry to choose the products with less impact on the environment and later on when disposing of the waste. Furthermore, there was an interest in encouraging design diminishing surface treatment.