Experimental Study On Connection Performance Of Cast Half-grouted Sleeves Considering Construction Defects

The connection between prefabricated concrete members is the key technology that affects the overall seismic behavior of the structure.Its connection performance directly affects the stability and durability of the structure.A lot of research has been conducted on different technical systems,seismic performance and engineering applications,but people have expressed concern about the construction quality and safety of vertical members of fabricated concrete structures.In this test,the cast half-grouted sleeve connection specimen is taken as the research object,considering the influence of various construction defects,the influence and degree of its connection performance are analyzed,which provides a reference for the realization of reliable connection of steel sleeve and the revision of specifications.1)172 connection specimens were designed and manufactured,the influence of two construction defects on the connection performance was considered,namely reinforcement defects(including 4 kinds)and grouting material defects(including 4kinds).With four standard test loading systems as the influencing factors,four aspects of the failure mode and ultimate bearing capacity of the specimen were studied.2)The connection specimens with different reinforcement defects are analyzed.The test results show that the effect of rib stripping is the greatest.When the stripping rib length coefficient increases to 100%,the failure mode of the specimens changes.The ultimate bearing capacity of the two sleeves decreases by 42% on average,and the bond strength decreases.The strength ratio and ductility ratio of the rib stripping specimens can not meet the requirements of the code,and the joint can not be used normally.3)The connection performance of sleeve with different grout defects is analyzed.The water-binder ratio has a greater impact on the compressive strength of the grout.The increase of its value directly affects the bonding effect of the grout and the steel bar.It is found that when the water-binder ratio increases from 0.12 to 0.24,the bearing capacity of the connection specimen decreases by 8.6% on average,and the ductility decreases by25% on average.The influence degree of all defect parameters is compared,and the problems in practical engineering are proposed.Figure 64;Table 26;Reference 52...