部分充填砼钢箱连续组合梁抗裂性能分析

针对部分充填砼钢箱连续组合梁裂缝控制问题,开展超高性能混凝土(UHPC)翼板-部分充填砼钢箱连续组合梁抗裂性能研究,探讨该组合梁裂缝控制的新途径.通过3根部分充填砼钢箱连续组合梁试验,得到挠度、滑移和裂缝的开展特征.基于ABAQUS软件建立部分充填砼钢箱连续组合梁有限元分析模型,分析UHPC翼板部分充填砼钢箱连续组合梁关键参数对受力性能的影响.结果表明:负弯矩区采用UHPC翼板能显著提高组合梁抗裂性能;当负弯矩区UHPC翼板长为0.3倍跨径、厚度为1/3翼板总厚时,能满足裂缝控制要求且经济合理;与普通混凝土相比,高应变强化UHPC初裂荷载提升2.3倍,可视开裂荷载提升7.6倍.

Analysis of Crack Resistance of Partially Filled Concrete Steel Box Continuous Composite Beams

Aiming at the crack control problem of partially filled concrete steel box continuous composite beams, the research on the crack resistance of ultra-high performance concrete(UHPC)flange-partially filled concrete steel box continuous composite beams is carried out, and a new way of this composite beam crack control is discussed. Through the test of three partially filled concrete steel box continuous composite beams, the deflection, slippage and crack characteristics are obtained. Based on ABAQUS software, a finite element analysis model of partially filled concrete steel box continuous composite beam is established. The influence of key parameters of the UHPC flange-partially filled concrete steel box continuous composite beam on the mechanical performance is analyzed. The results show that the use of UHPC flange in the negative bending moment zone can significantly improve the crack resistance of the composite beam; when the length of UHPC flange in the negative bending moment zone is 0.3 the span and the thickness is 1/3 of the total thickness of the flange, the requirements of crack control is satisfied, and it is economical and reasonable; by comparison with normal concrete, high strain strengthened UHPC initial cracked load increases by 2.3 times, and the crack-observed load increases by 7.6 times.