Recycled Aggregate Concrete for Structural Use – An Overview of Technologies, Properties and Applications

Abstract

By the end of the twentieth century generation of huge amounts of waste became one of the biggest environmental problems in the majority of the world. Construction and demolition waste (C&D) makes almost half of the total industrial waste. On the other hand, consumption of natural aggregate as the largest concrete component is constantly and rapidly increasing with the increase in the production and utilization of concrete. Recycling represents one way to convert a waste product into a resource. It has the potential to reduce the amount of waste disposed of in landfills and preserve natural resources while limiting environmental disturbance. This paper presents a review of traditional and advanced production technologies that make recycling of concrete in a completely closed loop technically feasible. The specific features of recycled aggregate concrete (RAC) mix proportioning meth- ods affected by the recycled aggregate (RA) properties are presented. The mechani- cal, rheological and durability properties of RAC based on up-to-date research are discussed from the point of the potential of its utilization in structural concrete. The current state of technical rules and standards in this area is briefly presented. The future research and necessary actions in facilitating the more extensive use of RAC in concrete structures are also pointed out.