关键词: 陶粒混凝土, 冻融循环, 动态力学性能, 抗压强度, 弹性模量

Abstract: With the purpose of studying the influences of the freeze-thaw cycle temperature and cycle times on the dynamic mechanical properties of ceramsite concrete, the freeze-thaw cycle test and the Hopkinson pressure bar compression test were performed. The upper limit of the freeze-thaw cycle temperature was +10 ℃ and its lower limit was -20 ℃ to -60 ℃ with the interval of -10 ℃. The sample size used in the tests is 150 mm×150 mm×100 mm, the dynamic compression test on samples after freeze-thaw cycle were carried out. The results show that either increasing the freeze-thaw cycle times or decreasing the freeze-thaw cycle temperature deepens on the damage of ceramsite concrete, reduces its dynamic compressive strength. When the cycle times reach 30 times, the elastic modulus of ceramsite concrete drops to approximately 60% of that prior to freeze-thaw cycle. Basically,the concrete elastic modulus follows a linear decreasing trend with the decrease of the minimum freeze-thaw cycle temperature. In addition, the compressive strength of ceramsite concrete declines with either the increase of the freeze-thaw cycle times or the reduction of the lowest freeze-thaw cycle temperature. Moreover, the strain corresponding to the maximum stress increases when the compressive strength decreases.

Key words: ceramsite concrete, freeze-thaw cycle (FTC), dynamic mechanical property, compressive strength, elastic modulus