Research on Seismic Behavior of Ordinary Concrete Brick Wall Strengthened with Sand High Ductility Concrete

Abstract:

The masonry structure has significant characteristics such as poor tensile, shear, flexural and seismic performance. To improve the seismic performance of the masonry structure, the experimental team used mechanism sand high toughness concrete (hereinafter referred to as MSHDC) as a special material for structural reinforcement. This material has remarkable properties such as high ductility and high strength. Through the method of pressing and coating a surface layer on the surface of the masonry specimens for reinforcement, the bearing capacity and seismic performance of the reinforced masonry structure were improved. This experiment produced four masonry walls. The wall material was ordinary concrete bricks+cement mortar. The blank test group and the test condition group were respectively un-reinforced, 35mm thick reinforced mesh cement mortar single-sided reinforcement, and 15mm thick MSHDC single-sided and double-sided reinforcement methods were used to reinforce the brick walls made at the same time. Through the low-cycle repetitive load test, the effect of the MSHDC surface layer on the seismic reinforcement of the masonry structure was explored. The results showed that the unreinforced wall exhibited a non-signaled, poor ductility brittle shear failure under low-cycle repetitive load, while the wall reinforced with the MSHDC surface layer exhibited a signaled, better ductility shear-compression failure. At the same time, the MSHDC surface layer reinforcement could effectively enhance the compressive bearing capacity, deformation capacity, stiffness, ductility and energy dissipation capacity of the wall. Compared with the un-reinforced specimens, the ultimate load and ductility of the MSHDC double-sided reinforced specimens increased by 44% and 49.4% respectively, and the enhancement effect was the strongest. In summary, the MSHDC double-sided reinforcement method had the strongest effect on enhancing the seismic performance of the wall, while the MSHDC single-sided reinforcement method was the weakest.