高温及冷却方式对混凝土在往复荷载作用下的应力应变特性的影响  

Influence of high temperature and cooling method on the stress-strain characteristics of concrete under cydic loading

作　　者：李建国 李庆涛 袁广林 LI Jianguo;LI Qingtao;YUAN Guanglin(Shanxi Institute of Technology,Yangquan 045000,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]山西工程技术学院,山西阳泉045000 [2]中国矿业大学力学与土木工程学院,江苏徐州221116

出　　处：《混凝土》2024年第10期58-61,73,共5页Concrete

基　　金：国家自然科学基金(51208504)。

摘　　要：对高温冷却后混凝土的抗压强度和应力应变特性进行试验研究,测试了5种温度(150℃、250℃、350℃、450℃、650℃)后经过空气中冷却和水中冷却至室温后混凝土的残余抗压强度和应力应变曲线,得到了温度和冷却方式对混凝土力学性能的影响规律。研究结果显示加热温度越高,冷却后混凝土的抗压强度退化程度的越多,并且空气中降至室温的混凝土明显优于在水中降至室温的混凝土的承载力。混凝土棱柱的峰值应力随受热温度升高而降低,且水中冷却后峰值应力明显低于空气中冷却的峰值应力,峰值应变随受热温度升高而增大,且水中冷却峰值应变高于空气中冷却峰值应变。高温能加剧混凝土的应力-应变曲线的刚度退化,水中冷却混凝土的刚度比空气中冷却混凝土的刚度下降更加明显。The concrete cube and concrete prism after high temperature were tested.The concrete specimens were heated at temperatures from 150℃,250℃,350℃,450℃,650℃,and then they were cooled in the air and water to room temperature.The residual compressive strength and stress-strain curve of concrete were tested.The influences of temperature and cooling methods on the mechanical properties were obtained.The results showed that the compressive strength of concrete cube reduced with temperature increasing,and the compressive strength of concrete cooled in air was higher than that of concrete cooled in water.The peak stress of concrete prism reduced with temperature increasing,and the peak stress of concrete cooled in air was higher than that of concrete cooled in water.The peak strain of concrete prism increased with temperature increasing,and the peak strain of concrete cooled in air was lower than that of concrete cooled in water.High temperature can exacerbate the stiffness degradation of the stress-strain curve of concrete,and the stiffness decrease of concrete cooled in water is more pronounced than that of concrete cooled in air.

关 键 词：高温 混凝土 往复荷载 力学性能 

分 类 号：TU528.064[建筑科学—建筑技术科学]