柱梁端受弯承载力比对局部FRC增强的梁柱组合体破坏机制影响的试验研究

Effect on ratio of column-to-beam flexural strength on failure mechanism of beam-column subassemblies with fiber-reinforced concrete

为研究在预期损伤部位采用纤维增强混凝土(FRC)和柱梁端受弯承载力比对框架结构破坏机制的影响,设计了5个带有翼缘板的不同柱梁端受弯承载力比值的梁柱组合体,其中4个试件的预期损伤部位采用FRC材料增强,1个试件全部采用普通混凝土。通过对试件进行拟静力试验,分析其破坏机理、变形和耗能性能以及承载力等。研究结果表明,与普通钢筋混凝土梁柱组合体相比,预期损伤部位采用FRC梁柱组合体的峰值荷载提高了13%,极限层间侧移角增大了17%,总耗能提高了40%,抗损伤能力明显提高;考虑梁两侧各6倍板厚翼缘宽度内钢筋对梁端弯矩的影响,当柱梁端受弯承载力比为1.2时,可基本实现强柱弱梁破坏机制,当比值为1.4时,可完全实现强柱弱梁破坏机制。

In order to investigate the impact of the ratio of column-to-beam flexural strength and using the fiber reinforced concrete（ FRC） at the expected damaged position on failure mechanism of frame structures,quasi-static tests were conducted on five one-half scaled beam-column subassemblies with different ratios of column-to-beam flexural strength,four of which used FRC at the expected damaged position,and one used normal RC completely. The seismic behavior,such as the failure mechanism,deformation,energy dissipation,bearing capacity,was analyzed. It is found that,compared with the RC beam-column subassemblies,the models with the FRC at the expected damaged position have higher resistance to damage,and the peak load increases by 13%,the ultimate drift ratio increases by17%,the cumulative total energy dissipation increases by 40%. Considering the effect of slab reinforcement in the flange width of 6-time slab thickness each side on the beam flexural strength,the beam-column subassembly achieves‘strong column-weak beam＇failure mechanism basically while the ratio of column-to-beam flexural strength is 1. 2,and could achieve ‘strong column-weak beam＇when the ratio is 1. 4.