Study On Longitudinal Steel Bar Connection Of Precast Superimposed Concrete Shear Wall And Its Seismic Behavior

To fully understand the precast superimposed concrete shear wall seismic performance,study new longitudinal steel bar connection reliability,improve the strength of the weak connection of steel bars and reinforced concrete interface connection,this paper put forward a new longitudinal steel bar connection based on the restraint groutinganchoring and suitable for superimposed concrete shear wall--Constrained concreteanchoring steel bar connection,and conduct a force performance test study about this lap way;design precast superimposed concrete shear wall test pieces which use constrained concrete-anchoring steel bar connection,conduct horizontal cyclic loading pseudo-static test,and compare with the performance of cast-in-place concrete shear wall;based on test and analysis results,put forward calculation method of horizontal bearing capacity about precast superimposed concrete shear wall,and authenticate it.This paper major research contents are as follows:1.The uniaxially tensioned steel bond slip test is carry out on 12 specimens and 24 test pieces lap test of constrained concrete-anchoring steel bar,get the ultimate bond strength of reinforced concrete and steel bar lapability with different hoop parameters,the results show that: the configuration of the spiral stirrups improve the ultimate bond strength,matching rate and ring diameter linear influence the ultimate bond strength;the lap performance of the large ring stirrup is better than that of the small ring.2.According to the lap test results of constrained concrete-anchoring steel bar,put forward a lap force model the model consider the different state of the force of the spiral stirrup before and after the cracking of the concrete,pose each stage parameters theoretical formula,by compare the theoretical and experimental values,propose suitable for practical engineering design and construction of the law of the formula,practical form and construction suggestions.3.According to pseudo-static test of 3 precast superimposed concrete shear wall test pieces and 3 cast-in-place concrete shear walls,acquire destruction process and destruction mode,frce characteristics,oerall stiffness and ductility,energy consumption,constrained concrete-anchoring steel bar strain process results of precast superimposed concrete shear wall,and compared with the cast-in-place concrete shear wall.The test show that: the mechanical performance and failure mode of the precast superimposed concrete shear walls are similar to those of the cast-in-place concrete shear walls,its bearing capacity and stiffness slightly lower than the cast-in-place concrete shear walls,but ductility and energy consumption are better than the cast-in-place concrete shear walls;precast shear wall longitudinal steel bar strain is greater than that of cast-in-place wall in the same position,it is shows that constrained concrete-anchoring steel bar lap way have a good mechanical performance,can be satisfy earthquake demand.4.Combine with the current design of cast-in-place concrete shear wall design calculation method and actual force characteristics of precast superimposed concrete shear wall,put forward a design considerations of compressive strength of compressed concrete in compressive zone with different value of stiffer restraint and unrestricted zone,pose the calculation method of the horizontal bearing capacity of the precast superimposed concrete shear wall;Based on lap test and seismic test results,and aim at precast superimposed concrete shear wall which use constrained concrete-anchoring steel bar lap way,put forward specific engineering design constructs.