New WRAP study compares leaching performance of recycled and secondary aggregates in concrete
New research published by WRAP (Waste & Resources Action Programme) has shown the leaching performance of concrete containing recycled and secondary aggregates to be similar to concrete made using aggregates from primary sources.
The study provides guidance and reassurance in an area where little information has been available to date and allows UK contractors and specifiers to further embrace the use of sustainable aggregates in concrete.
Using a variety of secondary and recycled aggregates – including recycled asphalt planings, foundry sand, incinerator bottom ash, crushed concrete and crushed brick – the report analysed the potential for elements within the aggregates to be leached from concrete into controlled waters such as groundwater and drinking water.
The study also determined that the best method of evaluating the suitability of recycled and secondary aggregates for use in concrete (in relation to their release of undesirable substances) was testing the material in accordance with BS EN 1744-3:2002.
John Barritt, technical advisor for aggregates at WRAP, explained: ‘Recycled and secondary aggregates have a key role to play in making the construction industry more sustainable and it is therefore important the industry is able to have full confidence in using these materials. It is also important the materials are shown not to have an adverse impact on either the properties of concrete or the environment in which they are used.
‘We were pleased to note the study found the performance of both primary aggregate and aggregates that come from recycled and secondary sources to be very similar, and we also identified a reliable testing method that can be used to determine the likely leaching performance of individual aggregates when used in concrete.’
The full report – Testing of Concrete to Determine the Effects on Groundwater – can be downloaded from: www.aggregain.org.uk
The study provides guidance and reassurance in an area where little information has been available to date and allows UK contractors and specifiers to further embrace the use of sustainable aggregates in concrete.
Using a variety of secondary and recycled aggregates – including recycled asphalt planings, foundry sand, incinerator bottom ash, crushed concrete and crushed brick – the report analysed the potential for elements within the aggregates to be leached from concrete into controlled waters such as groundwater and drinking water.
The study also determined that the best method of evaluating the suitability of recycled and secondary aggregates for use in concrete (in relation to their release of undesirable substances) was testing the material in accordance with BS EN 1744-3:2002.
John Barritt, technical advisor for aggregates at WRAP, explained: ‘Recycled and secondary aggregates have a key role to play in making the construction industry more sustainable and it is therefore important the industry is able to have full confidence in using these materials. It is also important the materials are shown not to have an adverse impact on either the properties of concrete or the environment in which they are used.
‘We were pleased to note the study found the performance of both primary aggregate and aggregates that come from recycled and secondary sources to be very similar, and we also identified a reliable testing method that can be used to determine the likely leaching performance of individual aggregates when used in concrete.’
The full report – Testing of Concrete to Determine the Effects on Groundwater – can be downloaded from: www.aggregain.org.uk
