U型组合再生混凝土-高强混凝土梁抗火性能  

FIRE PERFORMANCE OF U-SHAPED COMPOSITE RECYCLED AGGREGATE CONCRETE-HIGH STRENGTH CONCRETE BEAM

作　　者：肖建庄[1,2,3] 陈子璇 XIAO Jian-zhuang;CHEN Zi-xuan(College of Civil Engineering,Tongji University,Shanghai 200092,China;College of Civil and Architecture Engineering,Guangxi University,Nanning 530004,China;Institute of Science and Technology for Carbon Peak&Neutrality,Guangxi University,Nanning 530004,China)

机构地区：[1]同济大学土木工程学院,上海200092 [2]广西大学土木建筑工程学院,南宁530004 [3]广西大学双碳科学与技术研究院,南宁530004

出　　处：《工程力学》2024年第6期9-18,共10页Engineering Mechanics

基　　金：国家自然科学基金面上项目(52078358)。

摘　　要：为突破单一混凝土材料在受力和抗火两方面的性能难以协同优化的难题,该文创新性地提出U型组合再生混凝土-高强混凝土梁(简称为RAC-HSC组合梁),系统地开展了火灾试验和常温、火后受弯试验,综合分析了不同工况下组合梁的性能表现。研究表明:火灾下,RAC-HSC组合梁的耐火性能显著优于高强混凝土整浇梁,其梁内温度较低,跨中挠度较小,跨中未出现明显裂缝,且未观察到爆裂现象;常温及高温后的受弯试验中,RAC-HSC组合梁的屈服荷载、极限承载力及初始刚度均显著优于再生混凝土梁,基本达到或超过普通混凝土整浇梁和高强混凝土整浇梁的水平。该文所提出的U型组合再生混凝土-高强混凝土梁是混凝土构件“抗火-受力一体化设计”的有益尝试。To overcome the limitation of a single concrete material in achieving both favorable mechanical properties and effective fire resistance,a U-shaped composite beam consisting of recycled aggregate concrete(RAC)and high-strength concrete(HSC)was proposed in this study,referred to as the RAC-HSC composite beam.The fire resistance and bending behaviors before and after fire exposure of the RAC-HSC composite beam were studied,to comprehensively evaluate its performance under various conditions.The test results indicate that the fire resistance of the RAC-HSC composite beam was significantly superior to that of the HSC monolithic beam,exhibiting lower temperatures,reduced mid-span deflection,and fewer cracks,without any spalling phenomena under fire exposure.The yield load,load-bearing capacity and initial stiffness of the RAC-HSC composite beam were significantly higher than those of the RAC monolithic beam,approaching and even surpassing the bending performance of both normal aggregate concrete and HSC monolithic beams.Therefore,the U-shaped RAC-HSC composite beam represents a meaningful endeavor toward integrated design for the fire resistance and bending capacity of concrete components.

关 键 词：组合混凝土梁 再生混凝土 高强混凝土 抗火性能 受力性能 

分 类 号：TU375.1[建筑科学—结构工程]