宏观裂缝状态及渗透介质对混凝土渗透性的影响  

Influence of macroscopic crack state and permeable medium on the permeability of concrete

作　　者：蒋小旦 韩依璇 陈伟[3] JIANG Xiaodan;HAN Yixuan;CHEN Wei(Highway Development Center of Changzhou,Changzhou 213024,China;State Key Laboratory of Safety and Health for In-service Long Span Bridges,JSTI Group,Nanjing 211112,China;Hubei University of Technology,Wuhan 430068,China)

机构地区：[1]常州市公路事业发展中心,江苏常州213024 [2]在役长大桥梁安全与健康国家重点实验室,苏交科集团股份有限公司,江苏南京211112 [3]湖北工业大学,湖北武汉430068

出　　处：《新型建筑材料》2021年第10期151-156,共6页New Building Materials

基　　金：江苏省自然科学基金青年基金项目(BK20160144);湖北省自然科学基金面上项目(2017CFB604)。

摘　　要：针对存在宏观裂缝的混凝土材料,试验研究了裂缝开合度、环境温湿度变化以及水、气不同渗透介质对混凝土渗透性的影响规律。结果表明:初始裂缝开合度对渗透性的影响较大;裂缝开合度与围压存在非线性关系,在达到围压阈值20 MPa后,裂缝合并程度和气体渗透性的变化幅度降低;围压加卸载过程中,卸载段裂缝张开幅度低于加载段的合并程度,卸载段气体渗透性变化相对较小;由于高围压的作用造成粗糙的裂缝表面咬合更加紧密,裂缝宽度存在不可恢复的塑性变形结果。环境温湿度变化虽然能够带来裂缝表面的水蒸气吸附,但是对存在宏观裂缝的混凝土渗透性能的影响有限。The effects of the crack opening and closing,the change of temperature and relative humidity,and the different permeable media of water and gas on the permeability of concrete with macro crack were studied experimentally.The experimental results show that the initial degree of crack opening and closing has a great influence on the permeability.There is a nonlinear relationship between crack opening and closing degree and confining pressure.When the confining pressure reaches its threshold 20 MPa,the crack opening and closing degree and the variation range of gas permeability decrease.In the loading and unloading process of confining pressure,the crack opening amplitude during unloading phase is lower than the closing degree during loading phase,and the gas permeability change during unloading phase is relatively small.Due to the effect of high confining pressure,the occlusion of rough crack surface is more compact,and the crack width presents irreversible plastic deformation.Although the change of ambient temperature and humidity can bring the water vapor adsorption on the crack surface,its influence on the concrete permeability with macro crack is limited.

关 键 词：混凝土 裂缝 气体 液体 渗透性 

分 类 号：TU528.32[建筑科学—建筑技术科学]