大尺寸钢筋混凝土密肋薄腹梁抗剪性能试验

摘要

T he experiment on the shear behavior of four large‐size reinforced concrete multi‐ribbed thin web beams under concentrated loading was carried out , the force processes of bearing capacity ,cracking load ,failure characteristic and shear capacity were comparatively analyzed . T he results indicate that the force process of bearing capacity and failure characteristic of the multi‐ribbed thin web beams is similar to that of normal beams with web reinforcement .The cracking load and ultimate load of the specimen with precast floor are larger than specimen without precast floor .The flexural stiffness and overall operating performance of the specimens are improved by precast floor . Through the analysis of shear capacity of four specimens'experiment values and failure characteristic ,it is obtained that w hether the shear stirrup be fully utilized ,depends on the location and the angle of diagonal crack to a great extent .The comparing of ultimate shear capacities of experiment values and the calculated values according to various code provisions indicate that due to the main factors of code in some countries on different levels , the calculated values of shear capacity are not the same .The measured‐to‐calculated ratio of shear capacity is minimum by Chinese code and Germany code ,and the ratio is maximum by American code and United Kingdom code .%进行了4根大尺寸钢筋混凝土密肋薄腹梁在集中荷载作用下的抗剪性能试验，对其主要受力过程、开裂荷载、破坏特征及抗剪承载力进行了对比分析。结果表明：试验密肋薄腹梁的主要受力过程及破坏特征与普通有腹筋梁相似；有预制底板的试件开裂荷载和极限荷载比无预制底板的试件大，预制底板的存在还提高了试件的抗弯刚度和整体工作性能；通过分析4根试件抗剪承载力试验结果及破坏特征可知，受剪箍筋能否得到充分利用，在很大程度上取决于主斜裂缝的位置及倾角等因素；通过承载力的试验值与各主要规范计算值进行对比可知，由于各规范考虑因素及侧重程度不同，抗剪承载力计算值相差较大，中国规范和德国规范计算值与试验值比值最小，美国规范和英国规范比值最大。