Recycled aggregates in structural concrete – a Qatar case study

Despite established knowledge on the application of recycled aggregate in concrete, their use in structural concrete is somewhat limited. A sustainable supply of recycled materials together with adequate quality production and monitoring can enable wider use in high-value applications. Infrastructure in Qatar is being developed rapidly with large projects for the hosting of the World Cup 2022. One of the main challenges facing the construction industry is the lack of locally available good quality aggregates and the increased demand for aggregates. Industry relies on imported aggregates but there are concerns about quality and limited port capacity. Meanwhile, large quantities of construction wastes are available with potential to support the government strategy of green and sustainable construction. Recycled aggregates were subjected to extensive testing to optimise their use in structural C40 concrete and building trials were used to demonstrate how to apply this in practice. The results indicated at least similar strength and durability-related properties compared with imported aggregates. The project outcomes are being used to update the Qatar Construction Specification. A quality management system was developed to ensure a consistent supply of recycled aggregates and the project is now moving to implement recycled materials in government projects.