There are significant volumes of by-product materials such as ground granulated blastfurnace slag (GGBS) and fly ash that can act as part of the cementitious binder in concrete and masonry. There is also the opportunity to incorporate secondary aggregates, by-products from other processes, into masonry.
The recycled content for aircrete and aggregate blocks is approximately 31 per cent.
The blocks sector use of secondary aggregates and cement represents over 20 per cent of total tonnage. The aerated blocks sector use of secondary aggregates and cement is equivalent to over 70 per cent of total tonnage, as almost all aggregates used by the aerated sector is fly ash.
For more information about how the industry aims to increase the use of recycled concrete, download British Precast's Sustainability Matters report.