In order to study the crack characteristics of steel box-ultra-high performance concrete(UHPC)composite beam in negative bending moment zone,three partially-filled narrow steel box-UHPC flange composite beams with reinforcement ratios of 1％,2％and 3％were designed and manufactured.The crack development characteristics of the composite beams with different reinforcement ratios were observed by reverse loading test,and the maximum crack width,crack spacing and crack load were compared and analyzed.The research results show that the crack development of UHPC surface layer is obviously different with different reinforcement ratios.The higher the reinforcement ratio is,the smaller the maximum crack width,the denser the crack spacing and the greater the crack load become.Compared with the specimens with reinforcement ratio of 1％,the cracking bending moment of the specimens with reinforcement ratio of 2％and 3％increased by 30.3％and 65.2％respectively.The crack width of narrow steel box-UHPC composite beams in negative moment zone can be calculated with the crack width calculation formula in the Specifications for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts(JTG 3362-2018)by multiplying a correction factor of 0.78.
关键词
窄幅钢箱组合梁/配筋率/裂缝发展特征/负弯矩区
Key words
narrow steel box composite beam/reinforcement ratio/crack development characteristics/negative ben-ding moment zone
维普
万方数据