Influence of surrounding rock temperature on mechanical property and pore structure of concrete for shotcrete use in a hot-dry environment of high-temperature geothermal tunnel
Influence of surrounding rock temperature on mechanical property and pore structure of concrete for shotcrete use in a hot-dry environment of high-temperature geothermal tunnel
复制标题
高温地热隧道干热环境下围岩温度对喷射混凝土力学性能及孔结构的影响
DOI：
10.1016/j.conbuildmat.2019.02.125
复制
发表时间：
2019-05-20
影响因子：
7.4
通讯作者：
Guo, Chen
中科院分区：
文献类型：
--
作者：
Liu, Pin;Cui, Shengai;Guo, Chen
针对高温地热隧道的温度分布特点，将围岩温度分为40 ℃、60 ℃、80 ℃和100 ℃ 4个等级，模拟干热环境。以标准养护环境为参照条件，通过力学性能和压汞法（MIP）试验，研究了不同温度下干热环境下喷射混凝土的力学性能和孔结构特征。采用基于热力学方法的分形模型计算了孔隙结构的分形维数。对固化温度和孔结构参数进行了双变量相关分析。结果表明，40 ℃高温干燥环境有利于提高混凝土的力学性能，优化其孔结构，但7 d后高温干燥环境会恶化混凝土的力学性能和孔结构，且温度越高，恶化越明显。固化温度与毛细管孔隙率、中值孔径、平均孔径和分形维数之间存在显著的相关性。(C)2019爱思唯尔有限公司版权所有。
In view of the temperature distribution of the high-temperature geothermal tunnels, the surrounding rock temperature was divided into four grades (40 degrees C, 60 degrees C, 80 degrees C and 100 degrees C) to simulate the hot-dry environment. Using the standard curing environment as a reference condition, the mechanical properties and pore structure characteristics of concrete for shotcrete use under hot-dry environments at different temperatures were studied by mechanical and mercury intrusion porosimetry (MIP) tests. Fractal dimension of pore structure was calculated through the fractal model based on thermodynamic method. Bivariate correlation analysis was conducted on the curing temperature and the pore structure parameters. The results show that the 40 degrees C hot-dry environment is conducive to enhance the mechanical properties of concrete and optimize its pore structure at the age of Id. However, the hot-dry environments after 7 days will deteriorate the mechanical properties and pore structure of concrete, and the higher the temperature, the more obvious the deterioration. There is a significant correlation between curing temperature and porosity of capillary pores, median pore diameter, average pore diameter and fractal dimension. (C) 2019 Elsevier Ltd. All rights reserved.