火灾后混合配筋混凝土梁抗弯试验研究  

Experimental testing on the flexural capacity of hybrid-reinforced concrete beams after fire

作　　者：田敬博[1] 朱鹏[1] 屈文俊[1] 闫冰 TIAN Jingbo;ZHU Peng;QU Wenjun;YAN Bing(Department of Structural Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学建筑工程系

出　　处：《自然灾害学报》2019年第4期22-31,共10页Journal of Natural Disasters

基　　金：国家自然科学基金项目(51678430);国家重点研发计划项目(2017YFC0703003)~~

摘　　要：根据6根试验梁的耐火极限时间和火灾后试验梁的变化情况,选取未破坏的1根钢筋混凝土梁及2根混合配筋混凝土梁进行火灾后的静力加载试验,研究了火灾后钢筋混凝土梁和混合配筋混凝土梁的抗弯能力,讨论了钢筋-GFRP筋配筋比和荷载对混合配筋混凝土梁性能的影响,试验结果表明:1)火灾后混合配筋混凝土梁中GFRP筋的强度损失殆尽,钢筋的力学性能可以有一定程度的恢复,火灾后钢筋混凝土梁的力学性能恢复情况要优于混合配筋混凝土梁。2)纵筋中钢筋与GFRP筋的配筋比是影响混合配筋混凝土梁剩余承载能力的主要因素,钢筋与GFRP筋的配筋比越大,火灾后混合配筋混凝土梁的力学性能恢复越好。基于试验现象和理论分析,建议了火灾后混合配筋混凝土梁剩余抗弯能力计算方法,计算结果与试验结果吻合较好,可以用于工程计算。After fire tests of six reinforced concrete beams,one unbroken concrete beam reinforced with steel bars and two unbroken hybrid-reinforced concrete beams were subjected to static load tests according to the fire resistance time and their condition after fire. In this study, the flexural capacity of the concrete beams reinforced with steel bars and hybrid-reinforced concrete beams after fire are investigated. The influence of the ratio of the steel bars to GFRP bars and the load on the hybrid-reinforced concrete beams is discussed. The test results show: Firstly, the strength of the GFRP bars was basically wiped out, but the strength of the steel bars can restore to a certain degree after the fire. The restoring of the flexural capacity of the concrete beams reinforced with steel bars is better than that of the hybrid-reinforced concrete beams. Secondly, the residual flexural capacity of the hybrid-reinforced concrete beams is significantly influenced by the ratio of the steel bars to the GFRP bars. The larger the ratio is, the better the restoring of the flexural capacity after fire. Based on experiments and a theoretical analysis, a method for calculating the residual flexural capacity of hybrid-reinforced concrete beams is proposed. The results of calculation and experiment show a good agreement.It can be concluded that this method can be used for future engineering applications.

关 键 词：混合配筋混凝土梁 火灾后静力加载试验 钢筋-GFRP筋配筋比 剩余抗弯承载力 

分 类 号：X9[环境科学与工程—安全科学] X43