Chap-Yt – recycled aerated concrete aggregates in traditional screed for flooring

Aerated concrete is one of the few constituent parts of demolition rubble for which no valid recycling technology has been developed. Anno 2010 aerated concrete is a problem waste fraction. It is undesirable in the stony fraction (concrete rubble, mixed rubble) because of the poorer technical characteristics for the traditional applications in foundations and under foundations of roads. In addition, the chemical composition (leaching of sulphates) may also cause problems in other applications (embankment, supplement, concrete) or in landfills. Recycling the aerated concrete in the production itself (closing the loop) is only possible if the waste product is pure enough, which is after demolition works is not easy to guarantee. There is a need for applications within which this fraction of construction and demolition waste can be recycled, and preferably in as high as possible applications so that a direct or good market can be generated for aerated concrete waste. This paper discusses results from a MIP-project called “Chap-Yt”, in which milled recycled aerated concrete was used as an aggregate to partially replace sand in traditional hand-spread sand-cement screed for flooring purposes.status: publishe