混凝土高负温冻融损伤特性研究  

Research on Freeze-Thaw Damage Characteristics of Concrete at High Negative Temperature

作　　者：沈晨曦 王青[1,2] 刘俊 宋方疆 SHEN Chenxi;WANG Qing;LIU Jun;SONG Fangjiang(Hubei Key Laboratory of Disaster Prevention&Mitigation,China Three Gorges Univ.,Yichang 443002,China;College of Civil Engineering&Architecture,China Three Gorges Univ.,Yichang 443002,China)

机构地区：[1]三峡大学防灾减灾湖北省重点实验室,湖北宜昌443002 [2]三峡大学土木与建筑学院,湖北宜昌443002

出　　处：《三峡大学学报（自然科学版）》2021年第3期42-46,共5页Journal of China Three Gorges University：Natural Sciences

基　　金：国家自然科学基金项目(51379111);湖北省自然科学基金项目(2020CFB272)。

摘　　要：为研究(-5±2)℃~(5±2)℃高负温冻融循环温度下混凝土盐冻融和水冻融的抗冻性,采用质量损失率、相对动弹性模量和超声波速损失率三种指标对混凝土试件在水冻、盐冻、盐浇水冻和盐浇盐冻环境下进行测试,结果表明:各类试件经历150次冻融后,评价指标值远未达到混凝土试件停止试验时的最初设计标准;盐与水冻融间的差距也要比标准冻融循环温度下小.同时提出了一种新的混凝土冻融损伤评价指标—氯离子侵蚀面积占比,利用该指标测试表明,在(-5±2)℃~(5±2)℃的冻融循环温度下,混凝土氯离子侵蚀进程较同时长常温下浸泡后并不会加快.In order to study the frost resistance of salt freeze-thaw and water freeze-thaw of concrete under high negative temperature freeze-thaw cycle temperature of(-5±2)℃~(5±2)℃,this paper took mass loss rate,relative dynamic elastic modulus and ultrasonic velocity loss rate as evaluation indexes to carry out research under water freeze,salt freeze,salt water freeze and salt water freeze environment,respectively.The results show that after 150 times of freezing and thawing of various specimens,the evaluation index value is far from the original design standard when the concrete specimen is stopped the gap between salt and water freeze-thaw is also smaller than the standard freeze-thaw cycle temperature.At the same time,a new evaluation index for freeze-thaw damage of concrete-the proportion of chloride ion erosion area is proposed,the test using this index shows that under the freeze-thaw cycle temperature of-(5±2)℃~(5±2)℃,the chloride ion corrosion process of concrete will not be accelerated compared with the long-term soaking at room temperature.

关 键 词：混凝土 冻融损伤 耐久性 氯离子 

分 类 号：TU528.571[建筑科学—建筑技术科学]