News

4th International Conference on Autoclaved Aerated Concrete – Innovation and Development

8 – 9 September 2005 / Kingston University London

Information under http://strc.kingston.ac.uk/conference2005/

Call for papers_Jan2005.pdf, 4 pages, 376 kB

New Members

The following countries joined eaaca in 2004: Austria, Bulgaria, Czech Republik, Hungary, Slovakia, Slovenia and Sweden. eaaca now represents 17 European countries.

European Autoclaved Aerated Concrete Association

Comments on the Commission discussion paper on a draft Directive on energy performance of buildings

Introduction
The European Autoclaved Aerated Concrete Association (eaaca) promotes the interests of producers of autoclaved aerated concrete (AAC) and their national associations across all of Europe.

Produced for more than 70 years, AAC offers considerable advantages over other construction materials, one of the most important being its very high energy efficiency.

AAC has excellent thermal insulation properties, reducing the need for space heating or air conditioning in buildings. For many years, AAC has been used in the development of new building concepts for the realisation of low-energy houses.

Comments and information
eaaca welcomes the opportunity to present its comments on the discussion paper on the draft Directive of energy performance of buildings. We support the broad lines of the paper and welcome the Commission’s efforts towards an integrated approach in energy performance standards.

We support the integrated approach since the thermal quality of the building, heating installations, position and orientation of the building, heat recovery, active solar gains and use of renewable energy sources are all important elements of energy performance in buildings.

However, we believe that the energy savings potential offered by improvements in the building envelope should be given more detailed attention in the discussion document and the forthcoming directive.

While the Commission states in the paper that ‘improvements of the insulation of buildings are one of the major possibilities to reduce this consumption,’ it does not appear to recognise that insulation requirements can be met by using certain construction materials alone, and in particular AAC. AAC’s excellent inherent thermal insulation properties not only reduce the need for space heating and cooling, thereby cutting carbon dioxide emissions, but also make the use of additional insulation materials unnecessary.
Due to its porous structure, the thermal efficiency of AAC is 10 times that of normal concrete and 2-4 times that of clay brick. Both of these materials need to be used in combination with insulation products, thereby adding to their environmental impact and cost.

Greater use of AAC, both in new construction and renovation, thus represents a major way to reduce the energy consumption of residential and tertiary buildings across Europe.

We would respectfully ask the Commission to reflect this fact in its proposal for a directive by acknowledging AAC as an important solution to improving the energy performance of buildings.

In addition to its excellent thermal insulation qualities, AAC’s high resource efficiency gives it low environmental impact throughout its life cycle. Light in weight yet structurally robust, AAC’s production demands only small amounts of raw materials per m3 compared with other construction products. Production of AAC requires less energy than for clay bricks and all other masonry products. It does not create any toxic gases or water pollution.

Production waste is entirely recycled, while AAC’s easy workability in use allows accurate cutting that minimises the generation of waste during this stage of the life cycle. AAC from demolition sites can be reused or recycled. The product’s light weight also saves energy in transportation.

Moreover, AAC has further important attributes which, although not directly relevant to the forthcoming directive on energy performance, are nevertheless important in all types of construction:

• Excellent fire resistance: AAC provides the ultimate security against fire, resisting even intense heat and easily fulfilling all fire safety standards.

• Outstanding structural performance: AAC has an extremely high strength to weight ratio and is stable, making it the construction material of choice for buildings in earthquake zones.

We hope the Commission will take full account of AAC’s thermal insulation properties and other qualities in its proposal for a directive and would be happy to provide any further information you may require.

European Autoclaved Aerated Concrete Association

Comments on the Commission working document on management of construction and demolition waste

Introduction
The European Autoclaved Aerated Concrete Association (eaaca) promotes the interests of producers of autoclaved aerated concrete (AAC) and their national associations across all of Europe.

Produced for more than 70 years, AAC offers considerable advantages over other construction materials, one of the most important being its very low environmental impact.

AAC’s high resource efficiency gives it low environmental impact in all phases of its life cycle, from processing of raw materials to the disposal of AAC waste.

Comments and information
eaaca welcomes the opportunity to present its comments on the working document on management of construction and demolition waste. We support the broad lines of the working document and welcome the Commission’s efforts towards a proposal for a Council and Parliament recommendation on the management of construction and demolition waste.

We support the measures aimed at improving the management of construction and demolition waste stream in accordance with hierarchy of waste management principle by giving preference to prevention over re-use, material recycling, energy extraction and disposal. We agree that use of recycled materials for the manufacture of construction products must be encouraged.

However, the working document does not appear to recognise that prevention, recycling and disposal principles can be met by using certain construction materials, and in particular AAC. It applies the waste management principles in all phases of its life cycle.

Raw materials
AAC is made from naturally occurring materials that are found in abundance - lime, fine sand, other siliceous materials, water and a small amount of aluminium powder (manufactured from a by-product of aluminium) – plus cement. Some manufacturers use industrial by-products (pulverised fuel ash) in the manufacture of AAC, minimising waste from other industries.

Production
Thanks to continuous efficiency improvements, production of AAC demands relatively small amounts of raw materials per m³ of product, and up to a fifth as much as other construction products. No raw materials are wasted in the production process and all production off-cuts are fed back into the production circuit. The small amount of surplus material left over after curing is ground and recovered for other uses.

The manufacture of AAC requires less energy than for all other masonry products, thereby reducing use of fossil fuels and associated emissions of carbon dioxide (CO₂). Energy is also saved in the curing process since steam curing is carried out at relatively low temperatures and the hot steam generated in the autoclaves is reused for subsequent batches. Industrial-quality water is used and neither water nor steam are released into the environment. No toxic gases are created in the production process.

Transportation
AAC’s light weight also saves energy in transportation. The fact that AAC is up to five times lighter than concrete and three times lighter than clay brick leads to significant reductions in CO₂ emissions during transport. To reduce the need for transportation, AAC manufacturers apply the principle of producing as near to their consumer market as possible.

Use
AAC’s excellent thermal efficiency makes a major contribution to environmental protection by sharply reducing the need for space heating and cooling in buildings.

In addition, AAC’s easy workability allows accurate cutting that minimises the generation of solid waste during use. Unlike other building materials AAC does not need to be used in combination with insulation products, which increase the environmental impact and cost of construction.

Reuse, recovery and disposal
Throughout the life cycle of AAC, potential waste is reused or recycled wherever possible to minimise final disposal in landfill.

In some countries AAC manufacturers have taken on a voluntary commitment to recover separated and sorted AAC waste from construction and demolition sites for recycling and reuse. Homogenous AAC waste can be used in the production process as a valuable raw material. Importantly, AAC has achieved a recycling level of nearly 100%. Due to the reusability, AAC products may be used in Germany with the DIN-plus certificate which lays down manufacturer, product and environment related criteria. The licensee provides collection points for the return of unmixed AAC waste for industrial re-processing. Small residues of mineral plasters and mortars present no problem for the collection. Similarly, the coatings generally used for AAC components are not detrimental in terms of recycling. The applicant has to guarantee that the AAC manufactured by his company can be disposed of without problems at waste dumps as specified. Where AAC waste is sent to landfill, its environmental impact is minor since it contains no dangerous substances.

Greater use of AAC, both in new construction and renovation, thus represents a major way to improve construction and demolition waste management.

We would respectfully ask the Commission to reflect these facts in its proposal for a recommendation by acknowledging AAC as an important solution to improving management of construction and demolition waste.

Moreover, AAC has further important attributes which, although not directly relevant to the forthcoming recommendation of construction and demolition waste, are nevertheless important in all types of construction:

• Great energy efficiency: AAC has excellent thermal insulation properties reducing the need for space heating or air conditioning.

• Excellent fire resistance: AAC provides the ultimate security against fire, resisting even intense heat and easily fulfilling all fire safety standards.

• Outstanding structural performance: AAC has an extremely high strength to weight ratio and is stable, making it the construction material of choice for buildings in earthquake zones.

• Sound insulation: AAC has excellent sound insulation properties compared to other building materials with the same weight.

We hope the Commission will take full account of AAC’s environmental properties and other qualities in its proposal for a recommendation and would be happy to provide any further information you may require.