摘要
通过高温后静、动态压缩和劈裂试验,研究了高温后超高性能混凝土(ultra-high performance concrete,UHPC)力学性能,并通过扫描电镜(SEM)观察了高温后UHPC的微观结构,进一步揭示了高温后UHPC力学性能变化的原因。共设定了5种目标温度,即25℃(室温)、200℃、400℃、600℃和800℃,测试了120个试件。结果表明:UHPC静、动态强度均随温度升高呈现先增加后降低的趋势;在同一冲击速度下,UHPC的压缩与劈裂冲击韧度也随着作用温度的升高先增加后降低,但当冲击速度较小时,温度对冲击韧度影响不明显;拟合得到了UHPC应变率与动态增长系数(DIF)之间的变化范围;UHPC在不同目标温度(除800℃外)作用后拉伸动态增长系数(TDIF)随劈裂强度的升高而降低,UHPC受到的应变率增强效应随着UHPC劈裂强度的增加而减弱。
The mechanical properties of ultra-high-performance concrete(UHPC)after high temperature were studied by static and dynamic compression and splitting tests.Moreover,the microstructure of UHPC after different temperatures was observed by scanning electron microscope(SEM),which further revealed the reasons why the changes take place in mechanical properties of UHPC after different high temperatures.Five target temperatures were set,i.e.,25℃(room temperature),200℃,400℃,600℃,and 800℃,and a total of 120 specimens were tested.The results show that both the static and dynamic strength of UHPC increase first and then decrease with the temperature.At the same impact velocity,the compression and splitting impact toughness of UHPC also increases first and then decreases with the temperature.However,when the impact velocity is weak,the effect of temperature on the impact toughness is not significant.The formula for the variation range between strain rate and dynamic increase factor(DIF)was fitted in this study.The tensile dynamic increase factor(TDIF)of UHPC decreases first and then increases with the temperature(except 800℃).However,TDIF under different target temperatures(except 800℃)decreases with the increase of splitting strength,which shows that the strain rate enhancement effect of UHPC decreases with the splitting strength of UHPC.
作者
杨婷
杨烨凯
刘中宪
徐慎春
吴成清
YANG Ting;YANG Ye-kai;LIU Zhong-xian;XU Shen-chun;WU Cheng-qing(School of Civil Engineering,Guangzhou University,Guangzhou,Guangdong 510006,China;Earthquake Engineering Research&Test Center,Guangzhou University,Guangzhou,Guangdon 510006,China;Hebei Province Engineering Research Center for Harmless Synergistic Treatment and Recycling of Municipal Solid Waste,Yanshan University,Qinhuangdao,Hebei 066000,China;School of Civil Engineering,Tianjin Chengjian University,Tianjin 300384,China;School of Civil and Environmental Engineering,University of Technology Sydney,Sydney NSW 2007,Australia)
出处
《工程力学》
北大核心
2025年第4期97-109,共13页
Engineering Mechanics
基金
国家自然科学基金项目(51978186)
广州市科技计划项目(202102020565)
河北省高等学校科学技术研究项目(QN2023190)。
