BACKGROUND TO THE BSI PROVISIONS FOR RCA IN CONCRETE

摘要

The British Standards Concrete Committee wished to introduce provisions for recycled aggregates into its concrete standard (BS8500-2), but before it could do so a number of questions needed to be answered. Research undertaken at the University of Dundee provided answers to the questions raised by British Standards Institution (BSI) and this led to the introduction in 2002 of a full specification for the product and use of coarse recycled concrete aggregates (RCA) and a partial specification for other types of coarse recycled aggregates (RA). The reason for the high use of RCA in the UK and the Netherlands is that the Governments took measures to make the use of RCA competitive with primary materials. One key measure was the introduction of landfill taxes. This would be an effective measure in India to reduce the volume of construction and demolition waste provided 'fly tipping' can be minimised. Since 2002 the requirements for the use of coarse RCA and RA have only had very minor changes, but the requirements for the composition of the aggregate and the test method have been transferred from the BS8500-2 to the European aggregates standards. This paper describes the development of the clauses on recycled aggregate and the research that was needed to answer the questions raised by the BSI Concrete committee.