Research On Shear Behavior Of Mortarless Reinforced Block Masonry Shear Wall

Mortarless reinforced block masonry shear wall consisting of mortarless blocks by laying, the level and vertical reinforcement put in cavity and pouring concrete, can effectively speed up the construction progress, reduce the construction cost, and improve the quality of engineering, so it has bright prospect and has been applied widely in the field of affordable housing, post-disaster construction, construction of ordinary commercial housing, and villas. Shear wall as the main bearing structure, it is very important for the horizontal shear performance.In this paper, on the basis of experimental study on11pieces of mortarless reinforced block masonry shear walls under the various factors, such as height to width ratio,vertical pressure, horizontal reinforcement ratio, strength of core concrete and so on, to analysis the shear performance, and through software of ABAQUS to make the numerical simulation using the finite element method. Considering a large number of nonlinear contact exists in mortarless blocks, this article will make motarless block and pouring concrete into a equivalent material, and take this material to establish finite element model with steel bar. Fortunately, the method can effectively solve these problems about large number of numerical simulation calculation, time-consuming and difficult to convergence. This paper studies the main content and results are as follows:(1) According to the research of experiment, the characteristics of11specimens’ failure process mainly can be divided into bending shear failure and bending damage. The mainly failure process is that the tension side and the bottom of the wall discovered the first crack, with the level load increased, and along the bottom of the wall to the pressure side development, and have good capability and deformation. These factors of heignt to width ratio and the vertical pressure have greatly influence to the shear bearing capacity.(2) According to numerical simulation, through the way that make mortarless block and core concrete into a equivalent material, studies its macro monolithic compressive constitutive relation,and it can be well used to analysis of mortarless reinforced block masonry shear wall with FEM. The numerical results of11specimens’ bearing capacity and failure characteristics fit well with the experimental results.(3) According to numerical analysis, it is concluded that the factor of height to width ratio have greatly influence on shear bearing capacity of mortarless shear wall, and the shear bearing capacity of shear wall is reduced with the increase of the ratio of height to width, the best ratio of high to width H/B is1.0to1.2. At the beginning, the shear bearing capacity is increased with the increase of the axial compression ratio, but when the axial compression ratio between0.35and0.5, the shear bearing capacity is the largest, over the range, the shear bearing capacity decreased with the increase of axial compression ratio. As for horizontal reinforcement the best ratio is0.3%to0.4%, for vertical reinforcement the best ratio is0.4%, and for the compression strength of the block masonry,the best strength is16MPa to18MPa,because more than this range does little to improve the shear bearing capacity.(4) Through the way of regression and curve fitting to get the calculation formula of shear bearing capacity are more close to experimental results than the calculation formula regulated by the masonry structure design code (GB50003-2011).The research of this paper can provide the reference,when the engineering application and theory research of mortarless block masonry,or mortarless reinforced block masonry shear wall structure.