Briefing: New materials - some recent research

Recent and current research programmes on concrete materials at Liverpool University and Queen's University, Belfast, are briefly reviewed. These include work on recycling and the use of waste materials, influence of constituents on both construction and durability performance, and development of high-performance materials for specialist applications. Recycling work includes the use of construction and demolition waste as aggregates in concrete. This encompasses both crushed masonry and concrete, although contaminants present a major problem both for the concrete properties and the durability of embedded reinforcement. The effects of heavy metals on permeability and other physical properties have been examined, together with the prospects for encapsulation. Other work has focused on industrial production of unreinforced building blocks and paving flags, with full-scale factory trials. The use of cement replacements and slag-bound mixtures has also been considered in some detail, including potential applications in fast-track construction, as well as permeability as an indicator of durability performance. Ongoing work on high-performance materials includes consideration of strength, impact performance and blast-resistant characteristics.