断裂力学方法分析钢筋混凝土的抗裂度

采用断裂力学的方法,通过有限元分析,提出钢筋普通砼和钢筋陶粒砼受弯构件抗裂度计算公式。该方法全面考虑了砼强度等级、配筋率、受拉钢筋位置、试件尺寸效应对钢筋应力的影响,对大尺寸试件用Weibull尺寸效应反映,既考虑截面高度又考虑截面宽度的影响,计算更为合理。用此抗裂度计算公式对33根梁的计算结果与试验符合良好。本文公式不仅能解决一般受弯构件的抗裂度计算问题,同时可对带有较大显著裂缝(包括构造缝)的剩余截面进行抗裂度计算。

ANALYSIS OF CRACKING RESISTANCE STRENGTH OF REINFORCED CONCRETE BY FRACTURE MECHANICS

In this paper, on the basis of fracture mechanics by finite element analysis, the formula for evaluating the cracking resistance strength of ordinary reinforced concrete as well as reinforced ceramsite concrete bending members is presented. In the presented method the effects of concrete strength, steel ratio, location of tensile reinforcing bars, size of specimens on the stress of reinforcing bars is considered. For large size specimens Weibull's size effect is taken ioto account. Both effects of cross-section height and cross-section width are considered. These measures make the calculation more reasonable. Calculation results of cracking resistance strength of 33 beams by the present formula Show a good agreement with experimental resalt. In addition, by using the present formula the cracking resistance strength can be evaluated not only for ordinary bending members, but also for residual cross-section with obviously larger cracks (including constitutive cracks) can be evaluated.