International developments aimed at increasing the sustainability of concrete
Increasingly, sustainability is moving into the focus of international research on concrete technology. Among the most practically relevant current developments are those related to binder technology, the use of recycled fine and coarse aggregates, and durability design of concrete structures. The development of modern binder types involves substituting higher proportions of cement clinker with supplementary cementitious material. However, the current approach of using slag and fly ash is reaching its limits due to lack of sufficient and sustainable sources of these materials. Alternative low-CO2 and low-cost approaches are being investigated with the most promising strategy entailing the partial substitution of Portland cement clinker by the combined addition of calcined kaolinite clay and limestone. Concerning recycled aggregates, research into production methods and pre-treatment of aggregates is expected to significantly improve the technical properties of these materials and consequently increase their acceptance for industrial concrete manufacture. The presentation will discuss these developments and evaluate the expected impact on the production of precast concrete. In addition, it is argued that the superior durability properties of precast elements should be better utilized in the production and marketing of sustainable concrete.
Prof.-Dr. Hans Beushausen, Department of Civil Engineering, University of Cape Town, South Africa
Hans Beushausen is Professor in the Department of Civil Engineering at the University of Cape Town. He is a member of the Concrete Materials & Structural Integrity Research Unit, which focuses on infrastructure performance and renewal research. His research fields include concrete durability (material aspects, durability testing, durability design and specification), performance assessment of concrete structures, repair systems for concrete structures, and bonded concrete overlays. His interests further include precast concrete technology and he is editor of the magazine Concrete Plant International.