Research On The Shear Capacity Of The Wall When Mortar Is Used To Connect Horizontal Joints In The Low-Rise Prefabricated Wall Structure

With the construction of new countryside and new urbanization,the demand of low-rise assembly building is increasing.The horizontal joint connection form in assembly wall structure has an important influence on the mechanical performance of the wall and even the whole building structure.Therefore,it is of great scientific value to seek convenient,simple and practical horizontal joint connection form.Aiming at low-rise assembly building,this paper studies the shear resistance of assembly wall under a new type of horizontal connection,in which the wall slab and the ground beam are connected by grouting and the edge components are set at the end of the wall slab.Although the shear capacity of horizontal joints is weaker than that of reinforced sleeve joints and grouting-anchor joints in assembled reinforced concrete structures,the bearing capacity of horizontal joints in low-rise buildings is relatively small because of the small horizontal loads.Therefore,if this connection can meet the requirements of bearing capacity,it can be applied to low-rise assembled structures.In wallboard structure,it will have very important engineering application value.The main factors affecting the horizontal shear capacity of the wall are the strength and area of the steel bar passing through the horizontal joints,the axial compression ratio of the wall,the strength grade of mortar and the roughness of the interface.According to the composition characteristics of the wall studied in this paper,the main research contents are as follows:The relationship between shear capacity of horizontal joints and axial pressure is determined by monotonic loading tests of pure grouting wallboard under different axial compression ratios.The axial compression ratios are 0,0.05,0.1,0.2 and 0.3,respectively,according to actual engineering conditions.The results show that the shear capacity of horizontal joints increases gradually with the increase of axial compression ratio for pure slurry-saturated walls.The calculated values are basically in agreement with the experimental values by inversion of the relevant parameters of the calculation formulas in the existing literature,which indicates that the calculation formulas are reasonable and can be used to deduce the calculation formulas for the bearing capacity of walls with edge members.Low cycle reciprocating loading tests of reinforced concrete mortar-sitting walls with different shear span ratios were carried out.The shear bearing capacity of the wall when shear failure occurs along horizontal joints is measured,and the shear bearing capacity formula of the wall with edge components when shear slip failure occurs along horizontal joints is deduced.The formula will be directly applied to the shear design of low-rise fabricated wallboard structures.The results show that with the increase of wall section height and wall thickness,the ultimate bearing capacity of the wall increases in varying degrees.The calculated values are in good agreement with the experimental values,which indicates that the formula can be used to calculate the shear bearing capacity of the low-rise assembled slurry-sitting wall.On the basis of the agreement between the results of ANSYS finite element model and the test results,the influence of the section area of vertical reinforcement and the ratio of axial compression on the shear capacity of the wall edge members is simulated and analyzed.The simulation results show that the finite element simulation results are basically consistent with the test results,and the ultimate bearing capacity of reinforced concrete walls with edge members increases in varying degrees with the increase of the axial compression ratio and the vertical reinforcement diameter of edge members.