STATE-OF-THE-ART OF HORIZONTAL STRUCTURAL MEMBERS USING RECYCLED AGGREGATE CONCRETE

Horizontal structural members consume a huge amount of concrete and have low requirements for concrete properties, which provides a possibility to extend the structural applications of recycled aggregate concrete (RAC). This paper presents a brief review of the studies conducted by the authors and other researchers on the RAC material properties; the bond behaviour between steel and RAC; the mechanical behaviour of reinforced RAC slabs, reinforced RAC beams, composite steel-RAC slabs and composite steel-RAC beams. From the current studies, it can be concluded that reliable prediction models for the RAC material properties have been proposed using the abundant experimental data collected for the past three decades and these models could be used to predict the mechanical performance of structural members. Experimental studies and theoretical investigations were conducted on the flexural behaviour, the shear behaviour and the long-term behaviour of reinforced RAC slabs and beams, based on which their design procedures have been proposed by researchers and adopted by current RAC specifications. For the last decade, research efforts have been devoted to the flexural behaviour, the shear behaviour and the long-term behaviour of composite steel-RAC slabs and composite steel-RAC beams, and the feasibility of such members is validated. Probabilistic analysis on existing design procedures of reinforced RAC members needs further investigations, and studies on the fatigue behaviour, durability and fire resistance of RAC horizontal structural members need to be conducted in the future.