| The assembled precast concrete shear wall structure has the advantage of easy control of construction quality,short construction time,energy conservation and environment protection,high degree of industrialization and less cast-in-place concrete over the traditional shear wall structure.Nowadays,the assembled precast concrete shear wall structure has gained more and more attention.There are six common connection modes of vertical steel bar with different connecting effect and seismic capacity.The method of rebar lapping in grout-filled constrained hole in sheer wall is totally invented by the researchers and practioners of our country which is very suitable for the precast concrete structure with the industrialized mode of production.The early related experiments have showed that this kind of connection mode has satisfying connecting effect and seismic capacity.And it turns out to be cheaper and more convenient when compared with the method of rebar splicing by grout-filled coupling sleeve.However,because of the short time since the connection mode appeared,related experimental researches and theoretical explorations seems to be rather limited and mainly focus on the two factors of bar diameter and axial compression ratio.There is some virgin areas in this field remained to be explored.In order to meet the need of markets and guide the engineering application,some codes including the “Technical specification for assembled precast concrete shear wall structure” in Hubei province has suggested three connection modes called all connecting method,partly connecting method and method of using connecting steel bar.The purpose of this experiment is to take further exploration and analysis over the three connection modes and the cast-in-place shear wall structure aiming at their connecting effect and seismic capacity.The results will serve as experimental proof for the “Technical specification for assembled precast concrete shear wall structure” in Hubei province and provide some reference and suggestion for engineering application.Apart from that,this experiment has made a bold attempt about the ultimate lapping length and the details will be included in the following part.In order to achieve the goal,the article will include the following task:(1)The pseudo-static testing method was applied here.Five kinds of connection modes have been tested.They are all connecting method with rebar lapping in grout-filled constrained hole in 1.0 seismic anchorage length and 0.5 seismic anchorage length,partly connecting method,method of using connecting steel bar as well as cast-in-place concrete structure.Based on these work,this paper has analyzed and summarized every sheer wall's hysteresis loops,skeleton curves,carrying capacity and deformability,as well as the changing rule of strain of steel bar stiffness degradation,energy dissipation capacity.Meanwhile,the article has made a further comparison between the experimental data of the five sheer walls and explored the compact and influence of different connection modes.(2)Based on the experimental analysis,this article has compared and summarized the seismic performance of shear wall using different connecting modes,and consequently proposed some corresponding suggestions and preferences.(3)Aiming at the unsatisfied performance found in the shear wall using method of all connecting in 1.0 seismic anchorage length,this article has analyzed the causes considering the relevant conclusion,and offered some suggestions and opinion about the common problems in precast shear wall.The study of seismic performance of assembled precast concrete shear-wall structure has showed that the precast concrete structure using the method of rebar lapping in grout-filled constrained hole had equal seismic performance to the cast-in-place structure,which met the require of design codes in our country.The results of the experiment could be very helpful to the prefabricated construction's propaganda,researching and application.Given the huge amount of experimental task,the data obtained in the experiment and the corresponding achievements will be left to others in the same research team as raw data for finite element analysis,so more details will not be included in this article. |
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