Oct 31 2007
A new study published by WRAP (Waste & Resources Action Programme) provides further evidence that foamed concrete mixes using recycled and secondary aggregates offer comparable characteristics and levels of performance to those using primary material.
Researchers found the consistency, cube strength, drying shrinkage and leaching potential of foamed concrete using recycled and secondary aggregates to be comparable to that of equivalent sand foamed concrete. The study also revealed no significant variation in the performance of foamed concrete using recycled and secondary aggregates from single and multiple sources and the material can be recycled repeatedly requiring little energy consumption.
John Barritt, technical advisor for aggregates at WRAP, said: “The advantages of foamed concrete are becoming better understood by the construction industry but it is clear the majority of material produced still uses primary aggregate. This study builds on the research WRAP has already produced and further strengthens the case for using more sustainable aggregates in the production of foamed concrete.”
The new guidance builds on two previous WRAP-supported studies. The first found foamed concrete to be an ideal material through which the consumption of primary aggregates can be reduced, due to the high volume of air required in the mix and the fact coarse aggregate is not required in its composition. The second study found foamed concrete could be produced using a wide range of recycled and secondary aggregates as full or partial replacement for primary sand.
More detailed findings from the study have been incorporated into WRAP’s technical guidance document - Specification and Quality Control of Foamed Concrete Incorporating RSA - which is now available free from WRAP’s AggRegain website – www.aggregain.org.uk