基于简化拉-压杆模型的钢筋活性粉末混凝土框架边节点受剪承载力研究

对5个中间层钢筋活性粉末混凝土框架边节点试件进行了拟静力加载试验，得到了此类节点的破坏过程和破坏特点，明确了各阶段剪力的传递和分配。在试验研究的基础上，采用简化拉-压杆模型并考虑纤维抗拉拔阻力的有利作用，建立了钢筋活性粉末混凝土框架边节点在复合作用下的受剪承载力计算模型，并通过试验验证了此模型的可行性。结果表明:按照此模型计算得到的节点核心区受剪承载力与试验实测值吻合较好，离散度较小，其值与试验实测值的平均比值为1.05，变异系数为0.11；而且此模型亦能较合理地反映轴压比、配箍率及纵筋强度对节点受剪承载力的影响。

STUDY ON THE SHEAR BEARING CAPACITY OF EXTERIOR REINFORCED REACTIVE POWDER CONCRETE FRAME JOINTS BASED ON THE SIMPLIFIED SOFTENED STRUT-AND-TIE MODEL

Five exterior reinforced reactive powder concrete frame joints were tested under quasi-static loadings. The failure processes, the failure characteristics and the process to transfer and assign shears of the exterior joints were acquired. Based on the experimental study, the calculation model for the shear bearing capacity of exterior reinforced reactive powder concrete frame joints under the combined actions was proposed, in which the simplified softened strut-and-tie model was adopted and the favorable contribution of pullout resistance of fibers to the shear bearing capacity was considered. The feasibility of the model was verified by the experimental results of existing tested five specimens. The result indicated that not only the model can precisely predict the shear bearing capacity of the joint with less dispersion, it can also reflect the influence of axial compression ratio, stirrup ratio and reinforcement strength on the shear bearing capacity of the joints. The mean ratio of calculated results by the model and experimental results was 1.05, with a coefficient of variation valued at 0.11.