Research on performance of large diameter grout-filled splice sleeve joints with UHPC
Shao Xudong1 Liu Yeping1,2 Qiu Minghong1 Deng Fuhao1
1. Hunan Province Key Laboratory of Wind and Bridge Engineering, Hunan University, Changsha 410082, China;
2. Guangzhou Municipal Engineering Design and Research Insititute Co.Ltd, Guangzhou 510030, China
Abstract:The disease of assemble structure most due to the weakness of the connection joint. For sleeve connection, common problems include difficulty in filling multiple sleeves at the same time,cavity and reflowing aftre grouting,the quality assurance of grout strength and shrinkage, and the sealing of the sub-chamber at the bottom of the prefabricated component. In order to reduce the risk of weak joints caused by the above problems, it is proposed to use UHPC grouting material containing steel fiber and ultra-fine quartz sand to complete the connention of reinforcement bar and sleeve by gravity grouting. The method improves the construction safety and ensures the visualization of the pouring quality. Through the unidirectional tension test of 57 large diameter grout-filled splice sleeve gravity grouting connection specimens, the feasibility of connection mode was studied by changing the length of steel bars d, anchorage length la and grouting material types. The results show that specimens with steel bar meet the requirements of JGJ 355—2015 and JGJ107—2016 grade I joints. The sleeve is in the elastic stage in the test and meets the strength requirements. The safety reserve is high and the gravity grouting connection is feasible. The splitting resistance of grouting material is enhanced due to the bridging effect of steel fibers. UHPC grouting material containing steel fibers can further improve the bond strength between steel bar and grouting material and reduce the anchorage length of steel bar. The recommended critical anchorage length is 5.5d , which is 31.25% lower than the 8d required by JGJ355—2015.
邵旭东 刘也萍 邱明红 邓富颢. 采用UHPC灌浆材料大口径全灌浆#br# 连接套筒接头的性能研究[J]. 土木工程学报, 2020, 53(2): 81-91.
Shao Xudong Liu Yeping Qiu Minghong Deng Fuhao. Research on performance of large diameter grout-filled splice sleeve joints with UHPC. 土木工程学报, 2020, 53(2): 81-91.