钢筋混凝土连续梁火灾下抗剪性能的试验研究  

Experimental Research on Shear Behavior of Continuous Reinforced Concrete Beams in Fire

作　　者：杨志年 韩旭 舒升 王兴国 祝焕然 YANG Zhinian;HAN Xu;SHU Sheng;WANG Xingguo;ZHU Huanran(College of Civil and Architectural Engineering,North China University of Science and Technology,Tangshan 063210,China;Earthquake Engineering Research Center of Hebei Province,Tangshan 063210,China)

机构地区：[1]华北理工大学建筑工程学院,唐山063210 [2]河北省地震工程研究中心,唐山063210

出　　处：《结构工程师》2021年第3期88-96,共9页Structural Engineers

基　　金：河北省自然科学基金(E2021209112);河北省高等学校科学技术研究重点项目(ZD2021085)。

摘　　要：对8根足尺钢筋混凝土两跨连续梁和4根足尺钢筋混凝土简支梁进行了标准火灾试验,研究了钢筋混凝土连续梁高温下的抗剪性能,并与简支梁进行了对比,得到了连续梁混凝土及钢筋的温度变化、竖向挠度、轴向变形及最终破坏形态,分析了不同荷载比、剪跨比、混凝土保护层厚度、配箍率及受火工况对连续梁耐火极限的影响。结果表明:火灾下荷载比和混凝土保护层厚度对钢筋混凝土连续梁的抗剪性能影响显著。随着剪跨比和箍筋间距的减小,连续梁发生受剪破坏的耐火极限显著提高。与单跨受火工况相比,两跨同时受火的连续梁耐火极限降低。高温下连续梁由于发生了内力重分布,其抗剪性能优于简支梁。In order to study shear behavior of reinforced concrete continuous beams in fire,eight full-scale continuous beams and four simply supported beams were tested.The shear behavior of continuous beams was compared with that of simply supported beams.The distribution of concrete temperature,variation of rebar temperature,vertical displacement,axial deformation,and failure mode of the continuous beams were analyzed.The effects of loading ratio,shear span to depth ratio,thickness of concrete cover,stirrup reinforcement ratio and fire case on fire resistance of the continuous beams were compared.The results show that the loading ratio and thickness of concrete cover had significant influence on the shear behavior of continuous beams in fire.With the decrease of shear span to depth ratio and stirrup spacing,the fire resistance of continuous beams was observably improved.The fire resistance of continuous beams with two span heated was lower than that of continuous beams with one span heated.The shear resistance of continuous beams was better than that of simply supported beams,due to internal force redistribution at high temperature.

关 键 词：钢筋混凝土 连续梁 火灾下 抗剪性能 

分 类 号：TU375.1[建筑科学—结构工程]