基于黏结滑移-统计理论的再生混凝土梁裂缝宽度计算方法研究

Research on calculation method of crack width of recycled concrete based on statistical bond-slip theory

通过对不同配筋率、取代率两组10个再生混凝土梁构件进行裂缝宽度试验研究,对比分析了再生混凝土与普通混凝构件裂缝开展机理的不同,研究了再生混凝土裂缝开展机理、宽度影响因素,并在黏结滑移理论基础上结合试验统计数据推导再生混凝土构件裂缝最大宽度计算公式。研究结果表明:随着取代率的增加再生混凝土梁主裂缝旁分支裂缝不断增多,裂缝整体分布越趋复杂。配筋率变化对主裂缝宽度影响相当明显,配筋率增加再生混凝土裂缝宽度明显减小。基于黏结滑移-统计理论建立再生混凝土裂缝宽度计算公式,通过对多组试验结果反算验证该公式计算精度是满足设计要求的。

Through the test of ten recycled concrete beams with different reinforcement ratio and replacement, it was found that the crack developing mechanisms of recycled concrete and ordinary concrete were different.The crack developing mechanisms and width affection of recycled concrete were researched,The crack largest width calculation formula of recycled concrete was deduced,based on bond-slip theory and testing statistics.It is obtained that, the distribution of cracks were more and more complexed with the increasing replacement.The main crack width was influenced obviously by reinforcements.The crack width of recycled concrete was significantly reduced while the reinforce- ment ratio increasing.The calculation precision of the crack width formula was proved sufficient to meet the demand of design by the test rusults.