自密实混凝土高温冷却后的抗压性能试验研究  

Experimental study on compressive property of self⁃compacting concrete after high temperature cooling

作　　者：朱俊儒 张春涛[1] 王汝恒[1] ZHU Junru;ZHANG Chuntao;WANG Ruheng(School of Civil Engineering and Architecture,Southwest University of Science and Technology,Mianyang 621010,China)

机构地区：[1]西南科技大学土木工程与建筑学院,绵阳621010

出　　处：《建筑结构》2024年第16期93-99,共7页Building Structure

基　　金：国家自然科学基金项目(51508482);西藏自治区科技攻关计划项目(CGZH2018000014)。

摘　　要：为研究高温后自密实混凝土(简称SCC)抗压性能,制作了C35强度标准立方体混凝土试块48个,通过在不同温度下进行模拟火灾试验,分析了自然冷却和水冷却方式对高温后自密实混凝土试块的表观状态、抗压强度、峰值应力和破坏形态的影响。研究结果表明:两种冷却方式下试块的表观裂纹数目随着目标温度的升高而逐渐增多,试块在经历600℃和700℃高温后水冷却过程中,其边角出现明显剥落现象。两种冷却方式下试块的抗压强度呈现降低趋势,反常现象是300℃温度下采用自然冷却试块的抗压强度相较于100℃和200℃温度下的自然冷却试块有明显增强,增幅为8.1%和9.9%。自密实混凝土应力⁃应变曲线的峰值应力随着目标温度的升高而明显减小,所对应的峰值应变显著变大。最后,给出了自密实混凝土轴压应力⁃应变本构方程的参数取值,其拟合曲线能够与试验实测数据较好地吻合。To research the compressive properties of self⁃compacting concrete(SCC)after high temperatures,48 standard cubic concrete specimens with C35 strength were produced,and the effects of natural cooling and water cooling methods on the apparent state,compressive strength,peak stress,and failure shape of SCC specimens after high temperature were analyzed by conducting simulated fire tests at different temperatures.The results show that the number of noticeable cracks of the specimens under the two cooling methods gradually increased with the increase of the target temperature,and the edges of the specimens showed obvious spalling during the water cooling process after experiencing high temperatures of 600℃and 700℃.The compressive strength of the specimens under the two cooling methods shows a decreasing trend,however,there is an anomalous phenomenon that the compressive strength of SCC specimens with natural cooling after 300℃is significantly enhanced compared with that of the natural cooling specimens at 100℃and 200℃,with an increase of 8.1%and 9.9%.Meanwhile,with the increase in target temperature,the peak stress of the stress⁃strain curve of SCC decreased significantly,and the corresponding peak strain increased significantly.Finally,the parameters of the SCC axial compressive stress⁃strain constitutive equation were given,and the fitting curve can be in good agreement with the experimental data.

关 键 词：自密实混凝土 冷却方式 高温作用 抗压强度 破坏形态 本构方程 

分 类 号：TU528.53[建筑科学—建筑技术科学]