灌浆缺陷影响下装配式混凝土框架抗震性能试验研究

Experimental study on seismic performance of precast concrete frame with grouting defects

装配式结构中套筒连接常由于施工不当或套筒堵塞等原因造成灌浆缺陷,严重影响了装配式混凝土框架的抗震性能。为了评估存在套筒灌浆缺陷装配式框架结构的抗震性能,进行了1榀现浇框架和1榀环向灌浆缺陷率为30%的装配式框架的拟静力试验。研究结果表明:与现浇框架相比,30%灌浆缺陷率影响下装配式混凝土框架的承载能力下降了20%,抗侧刚度仅约为现浇框架的80%,刚度衰退也更为迅速;两榀框架的位移延性系数均在2.6~3.0之间,但环向灌浆缺陷率为30%的装配式混凝土框架的峰值位移和极限位移仅约为现浇框架的70%。因此,存在套筒灌浆缺陷的装配式框架结构抗震性能弱于现浇框架结构。

Defects arise in prefabricated concrete(PC)structures due to inappropriate construction or sleeve jam problems,which seriously affects the seismic performance of the PC frames.For a reasonable evaluation of the seismic performance of PC structures with grouting defects,it is necessary to study the influence of the grouting defects on the seismic performance.Therefore,quasi-static tests of a two-story,two-span cast-in-place frame and a PC frame of the same size but with 30%grouting defects were carried out in this research.The test results show that compared with the RC frame,the bearing capacity of the PC frame with 30%grouted defects is significantly reduced by 20%.The lateral stiffness of the PC frame is only 80%of the RC frame and the degradation rate is faster.The ductility coefficients are between 2.6-3.0,but the peak displacement and ultimate displacement of PC frame are only about 70%of the RC frame.Therefore,the seismic performance of assembled frame structures with sleeve grouting defects is weaker than that of cast-in-place frame structures.