考虑配箍率影响的RC梁-柱节点抗剪强度尺寸效应律

由于经典的混凝土尺寸效应律难以准确描述破坏机制更为复杂的RC构件破坏的尺寸效应行为,且无法定量描述相关参数对RC构件尺寸效应的影响.为此,以核心区剪切破坏的RC梁-柱节点为研究对象,在已有试验研究的基础上,采用三维细观尺度数值模拟方法,对影响节点剪切破坏性能的配箍率进行分析,研究其对RC梁-柱节点核心区剪切破坏行为及抗...

Size effect law on shear strength of reinforced concrete beam-to-column joints considering effect of stirrup ratio

The classical size effect law for concrete is difficult to accurately describe the size effect of reinforced concrete (RC) members with relatively complicated failure mechanism, and cannot quantitatively describe the influence of related parameters on the size effect of RC members. Therefore, the shear failure in the core area of RC beam-to-column joints were studied based on 3D meso-scale simulations. The effects of stirrup ratios on joints with shear failure were analyzed. The influence of stirrup ratio on shear failure in core area of RC beam-to-column joints and size effect of shear strength was studied.It is found that, on one hand, stirrups can improve the nominal shear strength of beam-to-column joints. On the other hand, they enhance the deformation capacity and reduce the brittleness degree of shear failure of joints, thus reducing the size effect on the shear strength of joints. Considering the influence mechanism of stirrup ratio, a semi-empirical and semi-theoretical formula of size effect of beam-to-column joints was proposed based on the shear strength size effect formula of RC beam without stirrups. The proposed formula can quantitatively consider the influence of stirrup ratio. In addition, the rationality and accuracy of the proposed predictive formula were confirmed by simulation and test results.