Physical properties of demolition waste material

Demolition waste materials, such as crushed concrete and bricks, have been utilised by the UK construction industry for applications such as the production of concrete, low-level backfill and road sub-base. There has been increased research into the properties of the recycled aggregates in the past decade but it mainly concentrates on the strength of these types of materials through shear box and triaxial tests. Little research has been undertaken on the physical properties of recycled materials, such as particle shape, water absorption and freeze–thaw resistance. This paper addresses the investigation of the physical properties of demolition waste materials for the purpose of re-use as engineering fill. It presents the physical characteristics of three types of commercially crushed concrete and brick materials, two of them being similarly based crushed concrete materials with different degrees of processing and one being crushed brick. Characteristics such as particle size distribution, particle shape, large-scale compaction, resistance to freeze–thaw and aggregate impact, and crushing values were established. The results show that there are similarities and differences between the two concrete-based materials. The characteristics of the brick-based materials are significantly different from the crushed concrete materials.