Experimental study on seismic performance of reinforced concrete frame columns supported with post-build wing walls

Six specimens of concrete frame columns reinforced by post-build wing walls on the opposite faces were designed and fabricated to investigate their seismic performance. Axial compression ratio was considered as the critical factor and divided into 0.31, 0.36, and 0.40 before reinforcement. HRB400 steel grade was used to the longitudinal bar and the ratio of longitudinal reinforcement divided into 1.23%, 1.05% and 0.82%, stirrup reinforcement ratio was 0.6%, and the stirrups were made by HPB300 steel grade. To meet with requirement of ‘strong shear, weak bending’, the ratio of the shear span to effective depth of columns was equal to 2.4. All specimens were subjected into cyclic reversing load. The testing results showed that wing walls reinforced significantly increased the seismic bearing capacity of the specimens and the wing walls damaged seriously, but the columns were not. The limited drift was ranged from 0.021 to 0.033. The post-build wing walls under horizontal motion may dissipate energy effectively while ensuring that the existing columns without obvious damage under vertical loads and earthquake strong motion.