| With the continuous transformation and upgrading of traditional residential construction industry and the general trend of residential construction industrialization,prefabricated structure has become a kind of architectural structure design system to meet the development requirements of this era.Among them,the structural technology system of composite slab concrete shear wall system is relatively complete,the design is simple,the construction is convenient and quick,and has little impact on the surrounding environment,which is in line with the strategic decision of accelerating the development and construction of green home building and realizing the green industrialization of home building in contemporary China.It is strongly supported by the state and local governments.The components of the new building main structure are composed of the composite wallboard after multi-layer wall superposition and the concrete components poured in the later stage,which are connected through the reliable integral connection combination mode to form a compact and integral prefabricated concrete wall shear wall structure.This kind of structure is made up of all the wall panel components,so the horizontal joint in the composite plate shear wall is worth discussing and studying.This paper makes a detailed comparative analysis and theoretical research on the overlapping structure principle and method of the overlapping steel bar at the horizontal joint of the laminated plate shear wall.Firstly,it introduces the connection method of the overlapping steel bar and the relevant regulations and requirements at home and abroad;Secondly,it makes a systematic analysis and Research on the principle of indirect reinforcement overlapping,introduces the basic structure of indirect reinforcement overlapping,and focuses on the analysis and Research on the spacing of indirect overlapping reinforcement;secondly,it introduces several factors that mainly affect the structural performance of overlapping reinforcement;Finally,the force transfer mechanism and the force transfer model of the lap joint with the lap joint reinforcement are compared and analyzed,which shows that the force transfer between the indirect lap joint reinforcement is realized by the bond stress between the reinforcement and the concrete.Secondly,according to the stress transfer law of overlapped steel bars at the horizontal joints of laminated plate shear wall structure,the specimens with different steel bar diameters are designed according to different structural measures of horizontal joints.Through the one-way pull-out test of the specimens,the failure mode,displacement load curve and steel bar strain of the specimens are analyzed and compared to study the tensile behavior of overlapped steel bars in different horizontal joints The stress-strain and stress transfer of steel bar during failure.The failure mode of the specimen shows that the stress of the concrete is mainly distributed in the contact surface between the steel bar and the concrete,while the damage is mainly concentrated in the contact point between the overlapping steel bar and the concrete and in the concrete,and extends along the steel bar.The failure position of the specimen is almost the same.The upper end of the single row overlapped steel bar has a good failure mode,and no large cracks appear,while the upper end of the double row overlapped steel bar has obvious cracks.There are different degrees of cable-stayed failure at the lower end of the specimen,which is mainly due to the insufficient thickness of the protective layer of the longitudinal tensile reinforcement in the precast slab.The yield point and limit value of single row lap 16 mm steel bar and double row lap 12 mm steel bar are basically the same,and the displacement load curve trend is basically consistent.The results show that the strain of the tensile reinforcement in the specimen changes obviously,because of the bond stress between the reinforcement and the concrete;when the reinforcement is tensioned,most of the stress generated is absorbed by the concrete of the layer,and the stress transferred to the precast layer or cast-in-place layer is low.In the single row member,the transfer efficiency of the steel bar at the joint is about 5%,and the transfer efficiency of the steel bar at the joint of the double row member is about 10.5%.Finally,the failure data of the steel bar are compared with the finite element analysis data of abaqus.Through comparison,it is found that the error between the stress transfer results of the finite element simulation and the test results is about 10% ～ 20%,the displacement load curve of the finite element simulation is similar to the curve obtained from the test,and the yield load and ultimate load of the model are basically consistent with the test results.It shows that the finite element model can accurately calculate the test results,so it is feasible to use the finite element to simulate the test.Figure [50] table [15] reference [64]... |
PDF Full Text Request