受火后钢筋混凝土吊车梁加固方法的试验研究  

Experimental research on strengthening methods of RC crane beams after fire

作　　者：陈玲珠 韩重庆 许清风 邵棚 王明谦 程杰 CHEN Lingzhu;HAN Chongqing;XU Qingfeng;SHAO Peng;WANG Mingqian;CHENG Jie(Shanghai Key Laboratory of Engineering Structure Safety,SRIBS,Co.,Ltd.,Shanghai 200032,China;Architects&Engineers Co.,Ltd.of Southeast University,Nanjing 210096,China;School of Civil Engineering,Southeast University,Nanjing 210096,China)

机构地区：[1]上海市建筑科学研究院有限公司上海市工程结构安全重点实验室,上海200032 [2]东南大学建筑设计研究院有限公司,江苏南京210096 [3]东南大学土木工程学院,江苏南京210096

出　　处：《建筑结构学报》2020年第8期134-142,共9页Journal of Building Structures

基　　金：“十三五”国家重点研发计划(2016YFC0701306);上海市科委标准项目(17DZ2202600)。

摘　　要：为研究受火后钢筋混凝土吊车梁的维修加固方法,开展了粘贴CFRP布和粘贴钢板加固受火后足尺吊车梁受力性能的试验研究、理论分析和有限元分析。结果表明:未受火对比试件发生受拉区钢筋屈服、受压区混凝土压碎破坏;粘贴CFRP布加固试件的主要破坏模式为受拉区钢筋屈服和CFRP布拉断;粘贴钢板加固试件的主要破坏模式为受拉区钢筋和加固钢板受拉屈服以及受压区混凝土压碎。对于ISO 834等效受火60 min后钢筋混凝土吊车梁,粘贴钢板加固效果优于粘贴CFRP布;ISO 834等效受火60 min和90 min后的钢筋混凝土吊车梁采用CFRP布加固后,极限荷载接近。加固后钢筋混凝土吊车梁试件跨中截面混凝土应变发展规律在混凝土腹板垂直裂缝完全发展前基本符合平截面假定。受火后加固试件的位移延性系数较未加固对比试件有所降低,粘贴钢板加固试件降低稍大。加固的受火后钢筋混凝土吊车梁极限荷载计算结果和有限元结果与试验结果误差绝对值为0.4%~7.8%,满足工程精度要求。Experimental,theoretical and numerical investigations on mechanical behavior of reinforced concrete(RC)crane beams strengthened by carbon fiber reinforced plastic(CFRP)sheets and steel plates were carried out to examine the behavior of the strengthened beams after fire.The test results indicate that the failure modes of the fire unexposed control specimen are the yielding of the steel bars in the tension zone and crushing failure of the concrete in the compression zone.The failure modes of the specimens strengthened by the CFRP sheets are governed by yielding of the steel bars in the tension zone and fracture failure of the CFRP sheets.The failure modes of the specimen strengthened by steel plates are governed by yielding of steel bars and steel plates in the tension zone and crushing of the concrete in the compression zone.For the specimens after 60 mins’equivalent ISO 834 standard fire exposure,the efficiency of the steel plate strengthening method was better than that of the CFRP sheet strengthening method.For the specimens exposed to 60 mins’and 90 mins’equivalent ISO 834 standard fire,their capacities are similar if strengthened by the same layers of CFRP sheets.The development of the concrete strain of the strengthened RC crane beams along the mid-span section basically follows the plane section assumption before the fully development of vertical cracks on the web.The displacement of the strengthened beams is significantly lower than the fire unexposed control specimen,especially for the beams strengthened by steel plate.The calculated and simulated capacity of the RC crane beams strengthened after fire exposure achieve good agreement with the test results(with errors between 0.4%and 7.8%),which meets the engineering accuracy requirements.

关 键 词：钢筋混凝土吊车梁 受火后 加固 静力试验 受力性能 

分 类 号：TU375.1[建筑科学—结构工程] TU317.1