摘要
采用ASTM C666快速冻融方法,对18个(6组)抗冻等级为D300的混凝土棱柱体试件分别进行N=0、100、150、200、250、300次冻融循环试验,并利用SEM扫描电镜观察冻融作用前后混凝土内部显微结构的变化,最后对各组试件进行单轴受压破坏试验,得到了不同冻融循环次数作用后混凝土的应力-应变试验曲线.根据试验结果,得出了混凝土随着冻融循环作用次数的增多,其内部结构以及各项基本力学性能(包括极限承载力、横向变形系数、弹性模量等)均呈现不同程度的衰减趋势,并建立了与相对动弹模损失率相关的应力-应变全曲线方程及相关参数,为进一步开展混凝土结构在冻融环境下的工作机理与计算模式的研究提供依据.
By adopting ASTM C666 quick freeze - thaw method, freeze - thaw tests, the number of freeze - thaw cycles being 0, 100, 150,200,250 ,and 300, were carried out on eighteen （ six groups） concrete prism specimens,the frost - resistant level of which reached D300 grade. The internal micro - structures of those specimens were observed through SEM in order to detect damages caused by freeze - thaw action. Afterwards those frozen - thawed specimens were tested on monotonic axial load, and stress - strain testing curves of con- crete after freeze - thaw action were obtained. The testing results showed that with the time of freeze - thaw cycles increasing both internal micro - structures and parameters of basic mechanical properties, including ulti- mate bearing capacity, Poisson ratio, modulus of elasticity, degenerated in various levels. Finally stress - strain theoretical curve equation and correlated parameters relating to the loss of relative dynamic modulus of elasticity were proposed. These results could offer references for further research of behavior and calculation model of concrete structures in freeze - thaw environment.
出处
《哈尔滨工业大学学报》
EI
CAS
CSCD
北大核心
2007年第2期229-231,共3页
Journal of Harbin Institute of Technology
基金
国家自然科学基金资助项目(50278025)
关键词
混凝土
冻融循环
应力-应变关系
力学性能
concrete
freeze-thaw cycle
stress - strain relationship
mechanical property
