Experimental research on local compression performance and bearing capacity calculation formula of UHPC
Li Chuanxi Zhang Yu Nie Jie Feng Zheng Tan Jinxiang
Hunan Key Laboratory of Green Construction and Maintenance of Bridges and Buildings，
Changsha University of Science & Technology，Changsha 410114, China
Abstract：The prestressed ultra-high performance concrete (UHPC) structure has the advantages of light weight and large span. In order to investigate the mechanical performance of its anchoring zone, with the steel fiber aspect ratio, local-compression area ratio and steel fiber content taken as variables, local-compression tests on 18 UHPC prism specimens with central holes are carried out, so that the local-compression bearing capacity and the load-displacement relationship of the specimens are obtained. Experimental results disclose that the local-compression cracking load of UHPC specimens is generally 45% to 78% of the local-compression limit load, and there is a long process of crack development before the local-compression failure. Under the local-compression, the specimens experience four stages: compaction, elastic deformation, crack development of peripheral concrete and its interface with wedge, and failure. The difference between the two groups of UHPC specimens with steel fiber length-to-diameter ratios of 65 and 80 respectively is small in the local compressive bearing capacity and local compressive stiffness. The vertical flexibility of the core concrete and the vertical flexibility of the relatively compressed concrete in the elastic deformation stage of the UHPC specimens increase with the decrease of the local compression area. When the content of steel fiber is increased from 1% to 2% and from 2% to 3%, the local compressive bearing capacity of UHPC specimens increases by 12.9% to 14.4% and by 7.4% to 7.6%, and the local compressive stiffness also increases with the content of steel fiber. The formula of calculating the local-compression bearing capacity of ordinary concrete is still applicable to that of UHPC, but the values of the correlation coefficient are different. By taking values using the proposed method, the calculated values agree well with our test results.
李传习 张宇 聂洁 冯峥 谭金祥. UHPC局压性能试验研究与承载力计算公式[J]. 土木工程学报, 2022, 55(3): 36-46, 93.
Li Chuanxi Zhang Yu Nie Jie Feng Zheng Tan Jinxiang. Experimental research on local compression performance and bearing capacity calculation formula of UHPC. 土木工程学报, 2022, 55(3): 36-46, 93.
