Abstract： In order to study the crack characteristics and evaluate the applicability of existing code for calculating the crack width of steel-UHPC composite deck, orthogonal tests were performed on 40 steel-UHPC composite slab specimens with variable parameters, including reinforcement ratio, cover thickness, thickness of UHPC layer, and spacing of studs. According to the test results, compared with the densely reinforced steel-UHPC specimen, the unreinforced steel-UHPC composite member has a small number of cracks, which may propagate rapidly after cracking. The cracks of densely reinforced steel-UHPC composite member are fine and dense with small opening width. In addition, before the crack width reaching 0.15mm, the load-maximum crack width curve of reinforced steel-UHPC composite is approximately linear, and the cracks develop quickly after the steel bars yield. When the crack width is larger than 0.2mm, the number of cracks basically remains unchanged. The reinforcement ratio and the cover thickness have great influences on the cracking stress and average crack spacing, while the effect from the thickness of UHPC layer is little. In terms of crack width of UHPC-steel composite structure, the calculation results with reference to existing code is overly conservative. Therefore, according to the characteristics of steel-UHPC composite deck structure and crack propagation, the calculation method of reinforcement stress is proposed in this study, and the calculation results agree well with the experimental results. Furthermore, based on the formulas in existing code, the formulas for calculating average rack spacing and non-uniform coefficient of steel strain are modified, and then the formulas for calculating the maximum crack width of steel-UHPC lightweight composite deck structure are developed. It is found that the calculation results from the proposed formulas are in good agreement with those from experiments.
邵旭东 罗 军 曹君辉 樊 伟 王 衍. 钢-UHPC轻型组合桥面结构试验及裂缝宽度计算研究[J]. 土木工程学报, 2019, 52(3): 61-75.
Shao Xudong Luo Jun Cao Junhui Fan Wei Wang Yan. Experimental study and crack width calculation of steel-UHPC lightweight composite deck structure. 土木工程学报, 2019, 52(3): 61-75.
