Micro-structure and Macro-performance:Surface Layer Evolution of Concrete under Long-term Exposure in Harsh Plateau Climate  

作　　者：CHEN Xin CUI Anqi ZHENG Haitao YANG Wencui HUANG Xin GE Yong LI Lihui 陈歆;葛勇;李立辉

机构地区：[1]School of Transportation Science and Engineering,Harbin Institute of Technology,Harbin 150090,China [2]Zhengzhou Engineering Co.,Ltd of China Railway Seventh Group,Zhengzhou 450052,China [3]Research Institute of Highway Ministry of Transport,Beijing 100088,China

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2024年第6期1496-1506,共11页武汉理工大学学报（材料科学英文版）

基　　金：Funded by the Science&Technology Project of the Department of Transport of Tibet Autonomous Region(No.XZJTKJ2020[04])。

摘　　要：We conducted a series tests on surface layers of plateau concrete at the ages of 180 and 540 days,including the most superficial cement paste,the 5 mm thick surface mortar,and the 50 mm thick surface concrete.Thermogravimetry and nitrogen absorption porosimetry on cement past,mercury intrusion porosimetry on mortar,and microhardness test on interface transition zone between mortar and coarse aggregate were conducted to evaluate the hydration degree and characterize the micro-structure.Whilst,tests for the rebound strength,abrasion resistance,and chloride ion impenetrability of concrete were conducted to assess the macro-performance.The experimental results show that,affected by the harsh plateau climate,outward surfaces have lower hydration degrees and worse pore structure than inward surfaces.As the hydration of concrete surface is ongoing after the age of 180 days,both the micro-structure and the macro-performance are continuously improved.In the long-term,either the orientation or the depth towards surface does not significantly affect concrete performance.Surface carbonation brings positive effects on mechanical properties but negative effects on the durability.Additionally,standard test result of chloride ion impenetrability is found significantly affected by the atmospheric pressure.For a same batch of concrete,charge passed in plateau regions is obviously lower than that in common regions.

关 键 词：CONCRETE pore structure interface transition zone mechanical property chloride ion impenetrability PLATEAU 

分 类 号：TU528[建筑科学—建筑技术科学]