配筋率对钢筋混凝土框架梁极限承载力的影响——拱效应试验研究

Influence of reinforcement ratio on ultimate bearing capacity of reinforced concrete frame beams:test study on arch action

通过对9根不同纵筋配筋率的钢筋混凝土试验梁进行加载试验,研究了纵筋配筋率对钢筋混凝土框架梁拱效应的影响以及拱效应条件下钢筋混凝土框架梁的极限承载力。试验结果和理论分析表明,钢筋混凝土框架梁中的拱效应可以使构件的极限承载力提高1倍左右;纵筋配筋率越低,极限承载力提高的幅度越显著。为提高拱效应的作用,宜将钢筋混凝土框架梁的纵筋配筋率控制在1.5%以内。

Nine specimens with different longitudinal reinforcement ratio were designed and fixed in the support with large stiffness and loaded in the midspan. Through the experiment, the influence of reinforcement ratio on the bearing capacity of reinforced concrete frame beams under the condition of arch action and the influence of arch action on their limit load were investigated. Experimental results and theoretical analysis indicate that the ultimate bearing capacity of reinforced concrete frame beams can be increased by 2 times under the arch action. The ultimate bearing capacity of reinforced concrete frame beams will be enhanced with decrease of the longitudinal reinforcement ratio. To enhance the role of arch effect, the reinforcement ratio of the longitudinal reinforcement should be controlled less than 1.5%.