轴向约束高强(纤维)混凝土柱抗火性能试验研究  

EXPERIMENTAL STUDY ON FIRE RESISTANCE OF AXIALLY RESTRAINED HSC & FRHSC COLUMNS

作　　者：王冠[1,2] 毛小勇[2] 杨才千[1] 金健 周立人[2] 史本龙[2] WANG Guan MAO Xiao-yong YANG Cai-qian JIN Jian ZHOU Li-ren SHI Ben-long(College of Civil Engineering, Southeast University, Nanjing 210096, China Jiangsu Key Laboratory of Structural Engineering USTS, Suzhou 215011, China Suzhou Jiang Nan Yi Zao Architectural Design Co. Ltd., Suzhou 215001, China)

机构地区：[1]东南大学土木工程学院,江苏南京210096 [2]苏州科技学院江苏省结构工程重点实验室,江苏苏州215011 [3]苏州江南意造建筑设计有限公司,江苏苏州215001

出　　处：《工程力学》2016年第11期174-182,共9页Engineering Mechanics

基　　金：江苏省"333工程"中青年学术带头人项目(2011-24);江苏省"六大人才高峰"人才项目(2012-JZ-004)

摘　　要：分别进行了ISO-834标准升温下轴向约束高强混凝土柱四面受火轴心、偏心荷载作用试验,三面受火轴心荷载作用试验;高强纤维混凝土柱四面受火和三面受火轴心荷载作用试验。得到了试件半高处截面各测点温度-时间曲线以及试件轴向位移-时间曲线、侧向位移-时间曲线、轴向约束反力-时间曲线,对试验中爆裂现象进行了分析。试验结果表明:高荷载比、高轴向约束刚度比下,高强混凝土柱初始爆裂出现较早;PP(聚丙烯)纤维的桥联作用,限制了早期爆裂的发生,熔融后形成孔道,抑制了后期爆裂;相同荷载比及受火边界条件下,荷载偏心作用降低高强混凝土柱耐火极限;三面受火条件下,柱出现向非受火面的弯曲;轴向约束条件下,受热膨胀阶段,柱中会出现附加轴力,对高强混凝土柱的初始爆裂时间有一定影响。Fire resistance tests were conducted on HSC（High Strength Concrete） columns exposed to fire on all sides under axial and eccentric loading, HSC columns exposed to fire on three sides under axial loading and FRHSC（Fiber Reinforced High Strength Concrete） columns in 4-and 3-sided fire exposure under axial loading. All the tests used ISO-834 standard fires and all the specimens were under axial restraint. Temperature at the mid-height of the specimens, deformation, axial constraint counterforce, and fire resistance were observed. The spalling which happened in the experiment was analyzed. The results show that, for HSC columns, high load and high axial restraint stiffness ratios result in initial spalling happening early in the fire exposure stage. Bridge connection from the inclusion of PP（polypropylene） fiber in the concrete mix reduces the risk of spalling happening in the fire＇s initial stage, and in the later stage including PP allows water vapor to escape from the pores caused by fiber melting. Eccentric load decreases HSC columns fire resistance under otherwise identical conditions. Bending deflection toward the unfired side arises when columns were placed under axial load in 3-sided fire exposure. Additional axial force, which arises in columns with axial restraint during the expansion stage, accelerates the occurrence of first spalling in HSC columns in fire.

关 键 词：高强混凝土 高强纤维混凝土 柱 试验研究 抗火性能 轴向约束 

分 类 号：TU352.5[建筑科学—结构工程]