Experimental study on the seismic performance of concrete shear walls partially replaced by MRPC

Shear wall structures are widely used in high-rise buildings, due to their satisfactory integrity and force transmission, thus superior seismic performance. However, due to insufficient material strength, non-standard construction, and the fact that some buildings have reached their design service life, many shear wall structures can no longer resist natural disasters such as earthquakes, nor can they meet the functional requirements. Therefore, it is of practical significance to reinforce shear wall structures and study their seismic performance. This paper uses the partial replacement method to reinforce and renovate concrete shear walls, using modified reactive powder concrete (MRPC) with excellent durability and toughness as the replacement material. The effects of different materials and different replacement positions on the seismic performance of shear walls were studied. A total of 5 shear wall specimens were designed and manufactured, including Specimen SW1 that did not reach the designed concrete strength, Specimen SW2 that met the original design strength, SW3 with the middle part of the wall was replaced by MRPC, and another two specimens that used ordinary concrete (SW4) or MRPC (SW5) to replace the two ends of the wall. Pseudo-static tests were carried out on the specimens and their seismic performance indicators such as bearing capacity, stiffness degradation, displacement ductility, and energy dissipation capacity were analyzed. Finally, finite element simulation analysis was also performed for the specimens. The results show that compared with the original design strength specimen SW2, the specimens SW4 and SW5, which used C45 concrete and MRPC to replace the two ends of the walls, effectively improved the bearing capacity, energy dissipation, and ductility of the shear wall. By comparing the mechanical properties of SW3 and SW5, it can be found that replacing the two ends of the shear wall can obtain better results.