摘要
为研究高温作用后不同冷却方式对混凝土力学性能及损伤演化的影响,利用声波仪及力学测试系统分别对经400℃高温处理后的混凝土试件在不同冷却条件下的波速和单轴强度进行测试,分析混凝土力学特性、测试波速、变形特性及损伤的演化规律。通过试验结果得出如下结论:①相对其他冷却方式,半水冷条件下由于试件变形不均匀,混凝土强度劣化最严重;②混凝土泊松比和弹性模量的变化表明,半水冷条件下试样变脆,承载能力降低,且较自然冷却条件、全水冷条件,半水冷条件对混凝土弹性模量的劣化最为严重;③在自然冷却、全水冷、半水冷3种冷却条件下,混凝土试样测试波速分别为2.56,2.57,2.42 km/s,分析试验损伤系数分别为0.480,0.476,0.534,表明半水冷条件对高温作用后的混凝土损伤最大。研究成果对高温条件下混凝土工程设计及高温作用后混凝土结构的加固具有一定参考价值。
In order to explore the impact of different cooling conditions on the mechanical properties and damage evolution of concrete after high temperature treatment,the wave velocity and uniaxial strength of concrete specimens were measured by sonic instrument and a mechanical testing system.According to the results,the concrete strength deteriorated the most under half water-cooling condition compared with other cooling conditions.Meanwhile,the analysis on Poisson s ratio and elastic modulus of concrete specimens showed that the half water-cooling condition had the great impact on concrete bearing capacity and crisped the concrete.Under the three cooling conditions of natural cooling,full water-cooling and half water-cooling,the test wave velocities of concrete samples were 2.56,2.57 km/s and 2.42 km/s,and test damage coefficients were 0.480,0.476 and 0.534 respectively,which showed that the half water-cooling damaged the concrete most after the high temperature treatment.The conclusions can be applied to the design and maintenance of concrete structure after high temperature.
作者
庄志凯
张伟
张坤
卢晓仓
陈勇
ZHUANG Zhikai;ZHANG Wei;ZHANG Kun;LU Xiaocang;CHEN Yong(PowerChina Guiyang Engineering Co.,Ltd.,Guiyang 550081,China;College of Civil Engineering,Guizhou University,Guiyang 550025,China)
出处
《人民长江》
北大核心
2023年第4期229-233,共5页
Yangtze River
基金
贵州省科技计划项目(黔科合支撑[2017]2036)
国家自然科学基金项目(52078261)。
关键词
高温作用
混凝土损伤
冷却方式
波速
力学性能
high temperature treatment
concrete damage
cooling methods
wave velocity
mechanical property
