PERFORMANCE OF RECYCLED AGGREGATE CONCRETE (RAC) - FILLED STEEL TUBULAR STRUCTURES

Filling steel tubes with recycled aggregate concrete (RAC) to form RAC-filled steel tubular (RAC-FST) structural members may provide an alternative approach of utilizing RAC, because the disadvantages of material properties of RAC could be compensated by the use of outer steel tube and the resultant composite action. This paper first presents a literature review on the research of structural behaviour of RAC-FST members in recent years. Then it illustrates major findings from recent studies conducted by the first author's research group. These studies focused on the bond behaviour between steel tube and infilled RAC and the structural behaviour of RAC-FST members subjected to various actions, e.g., short/long-term sustained loading, cyclic loading, fire exposure. These studies contributed to the development of a design specification that provides guide for the design of RAC-FST structures. The contents of this design specification are finally introduced.