摘要
通过设计强度等级C40、C50及C60混凝土的低温冻融循环作用试验,探讨不同混凝土强度等级对其弹性模量的影响。选取的低温冻融循环作用温度区间为15℃—-120℃和15℃—-190℃,冻融次数分别取0次、16次和30次。结果表明,各强度等级混凝土经历不同温度区间低温冻融循环作用上限温度时的相对弹性模量均随冻融循环作用次数增加而减小,而下限温度时则随冻融循环作用次数增加不仅不降低还略有增大。无论是作用的温度区间和冻融次数不同还是上下限温度时加载,其相对弹性模量均随混凝土强度等级的提高而增加。各强度等级混凝土弹性模量变化特征明显不同于自然环境的常规冻融试验结果,较少的冻融循环作用次数便使其产生严重的恶化。
The effects of different strength grades including C40,C50 and C60 on concrete elastic modulus were discussed through the low temperature freeze-thaw cycle action test.The considering freeze-thaw temperature ranges were 15℃^-120℃and 15℃^-190℃,and the freeze-thaw times were 0,16 and 30 times respectively.The test results show that the relative elastic moduli for all strength grade concretes decrease with increase in freeze-thaw cycle times at upper limit temperature of above-mentioned two temperature ranges,while at lower limit temperature they not only don’t decrease but also slightly increase.However,the relative elastic moduli increase with increase in concrete strength grade,whether their freeze-thaw temperature ranges and cycle times are different,or the concrete is loaded at upper or lower limit temperature.Moreover,the elastic modulus performance for all strength grade concretes experiencing low temperature freeze-thaw cycle action is obviously different from the results of normal freeze-thaw test in natural environment,which tended to deteriorate when starting to experience freeze-thaw cycle action.
作者
时旭东
田佳伦
汪文强
Shi Xudong;Tian Jialun;Wang Wenqiang(Department of Civil Engineering,Tsinghua University,Beijing 100084,China)
出处
《低温工程》
CAS
CSCD
北大核心
2019年第6期26-31,61,共7页
Cryogenics
基金
国家自然科学基金项目(51878375、51478242)
关键词
低温
冻融循环作用
混凝土
强度等级
弹性模量
low temperature
freeze-thaw cycle action
concrete
strength grade
elastic modulus
