Experimental study on reuse of recycled concrete aggregates for load-bearing components of building structures

Recycled aggregates recovered from abandoned buildings or demolished concrete structures were reused to produce concrete columns as new building components. A quasi-static test on 10 recycled aggregate concrete filled steel tubular (RACFST) columns was carried out. The mechanical properties of RACFST columns in the study include failure mode, hysteretic loops, skeleton curves, stiffness deterioration curves and energy dissipation capacity. RACFST columns with different recycled aggregate replacement ratios were tested under constant axial load and cyclic lateral load. The seismic performance of the columns was analyzed. The experimental results indicate that concrete adding recycled aggregates does not reduce the lateral stiffness of the columns, and their energy dissipation capacity is nearly as good as that of natural aggregate concrete filled steel tubular columns. The usage of recycled aggregate concrete has little influence on the lateral load-bearing capacity and the stiffness deterioration of RACFST columns. The current calculation for natural aggregate concrete filled steel tubular columns to estimate the lateral load-bearing capacity of RACFST columns tends to be relatively conservative. The reuse of recycled aggregates for load-bearing components of building structures especially for concrete filled steel tubular columns is feasible.