Sandstone-concrete interface transition zone (ITZ) damage and debonding micromechanisms under freeze-thaw  

作　　者：YanJun Shen Huan Zhang JinYuan Zhang HongWei Yang Xu Wang Jia Pan 

机构地区：[1]School of Geology and Environment,Xi'an University of Science and Technology,Xi'an,Shaanxi 710054,China [2]Geological Research Institute for Coal Green Mining,Xi'an University of Science and Technology,Xi'an,Shaanxi 710054,China [3]Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation,Xi'an,Shaanxi 710054,China [4]School of Architecture and Civil Engineering,Xi'an University of Science and Technology,Xi'an,Shaanxi 710054,China

出　　处：《Research in Cold and Arid Regions》2021年第2期133-149,共17页寒旱区科学（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No.41772333);the National Natural Science Foundation of Shaanxi Province, China (Grant No.2018JQ5124);the New-Star Talents Promotion Project of Science and Technology of Shaanxi Province, China (Grant No.2019KJXX049)。

摘　　要：The sufficient bond between concrete and rock is an important prerequisite to ensure the effect of shotcrete support. However, in cold regions engineering protection system, the bond condition of rock and concrete surface is easily affected by freeze-thaw cycles, resulting in interface damage, debonding and even supporting failure. Understanding the micromechanisms of the damage and debonding of the rock-concrete interface is essential for improving the interface protection.Therefore, the micromorphology, micromechanical properties, and microdebonding evolution of the sandstone-concrete interface transition zone(ITZ) under varying freeze-thaw cycles(0, 5, 10, 15, 20) were studied using scanning electron microscope, stereoscopic microscope, and nano-indentation. Furthermore, the distribution range and evolution process of ITZ affected by freeze-thaw cycles were defined. Major findings of this study are as follows:(1) The microdamage evolution law of the ITZ under increasing freeze-thaw cycles is clarified, and the relationship between the number of cracks in the ITZ and freeze-thaw cycles is established;(2) As the number of freeze-thaw cycles increases, the ITZ's micromechanical strength decreases, and its development width tends to increase;(3) The damage and debonding evolution mechanisms of sandstone-concrete ITZ under freeze-thaw cycles is revealed, and its micromechanical evolution model induced by freeze-thaw cycles is proposed.

关 键 词：sandstone-concrete interface transition zone(ITZ) freeze-thaw cycles nano-indentation damage and debonding 

分 类 号：TU528[建筑科学—建筑技术科学]