Study On Seismic Performance Of A Novel Steel Wire Grids Concrete Sandwich Composite Wall

Composite sandwich materials made of concrete and insulation materials is an superior material to replace traditional wall material.It is widely concerned because of its high thermal insulation efficiency and low construction cost.Based on the traditional insulation concrete sandwich structure,the thin-walled cold-formed steel and reinforced concrete embedded columns are added.Thus,a new cast-in-situ insulation sandwich concrete wall structure is proposed,which is mainly composed of the thin-walled cold-formed steel,slant steel wire connector,steel wire meshes,concrete layers,expanded polystyrene sheet and reinforced concrete embedded column.In order to assess the hysteretic properties of the new insulation sandwich concrete wall and the influence of various parameters on the bearing capacity,and to provide data support and indicators for the actual design,the following research is conducted:(1)The low-frequency horizontal cyclic load tests were carried out on 7 full-scale specimens of unconstrained cast-in-situ concrete sandwich wall,and 4 parameters including thickness of concrete layers,steel wire spacing,concrete strength grade and axial compression ratio were considered.(2)The low-frequency horizontal cyclic load tests were carried out on two T-shaped sandwich wall specimens and two L-shaped sandwich wall specimens,and two parameters of boundary element and section shape are considered.(3)The load-displacement response and damage distribution of single specimens were simulated by ABAQUS software,and the influence factors of bearing capacity are analyzed synthetically.(4)Based on the formulas for calculating the shear bearing capacity of shear wall in current specifications,the formula coefficient is modified,and the shear bearing capacity formula suitable for the structure in this paper is put forward.Through the above research,the following main conclusions are obtained:(1)Under the action of horizontal load,the integrity of the two concrete layers and the insulation layers of the single sandwich wall specimen is good,and there is no detachment,and the failure form is the bending shear failure dominated by shear failure.(2)The greater the thickness of concrete layer,the greater the axial compression ratio and the higher the concrete strength,the greater the horizontal bearing capacity.However,the steel wire spacing has almost no effect on the bearing capacity,but has a greater impact on the ductility.The smaller the steel wire spacing is,the better the ductility of the specimen is.(3)The failure of T-shaped and L-shaped joints was caused by the complete breakage of webs.After reaching the peak bearing capacity,the bearing capacity degradation of T-shaped joints was more stable than that of L-shaped joints.The hysteretic properties such as bearing capacity,ductility,stiffness degradation and energy dissipation of specimens with boundary element are better than those without boundary element.(4)The existing shear bearing capacity formula of shear wall can be used to calculate the shear bearing capacity of the structure in this paper reliably after coefficient modification.