EXPERIMENTAL INVESTIGATION ON THE SEISMIC BEHAVIOR OF FLEXURAL UNREINFORCED MASONRY WALLS STRENGTHENED BY HIGH DUCTILITY CONCRETE OVERLAYS

To study the seismic behavior of flexural unreinforced masonry walls strengthened with High Ductility Concrete (HDC) overlays, an unreinforced brick wall, a wall retrofitted with steel-meshed cement mortar and three walls strengthened with HDC overlays were designed. Quasi-static tests were performed to study the failure mechanism, hysteretic characteristics and energy dissipation capacity of the brick walls. The results shows that:the bonding properties between the HDC overlays and brick walls are excellent, and the HDC overlay is effective to limit the crack and damage and avoid brittle failure; the HDC overlay has good restraining effect on the brick walls and improves the seismic performance of the brick walls; the HDC overlay can significantly improve the damage tolerance and deformability and reduce or avoid the repair expenses after earthquakes. Its effectiveness is better than a traditional steel-meshed. According to the statistical analysis, this paper gives the fragility curve based on the drift of walls strengthened by HDC layers.