硫酸盐冻融后沙漠砂混凝土单轴受压力学性能试验研究  

Experimental Study on the Uniaxial Compressive Mechanical Properties of Desert Sand Concrete After Sulfate Freeze-thawing

作　　者：姜彦杰 刘浩天 刘海峰[1] 车佳玲[1] 杨维武 JIANG Yanjie;LIU Haotian;LIU Haifeng;CHE Jialing;YANG Weiwu(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学土木与水利工程学院,银川750021

出　　处：《材料导报》2025年第7期115-125,共11页Materials Reports

基　　金：国家自然科学基金(52168034);宁夏自然基金(2023AAC03039);宁夏高等学校一流学科建设(水利工程学科)资助项目(NXYLXK2021A03)。

摘　　要：为研究沙漠砂混凝土(DSC)在硫酸盐冻融环境下抗冻性能及力学性能劣化规律,以沙漠砂替代率(DSRR,0%、20%、40%)、硫酸盐溶液质量分数(3%、5%、7%)及冻融循环次数(0、25、50、75、100、125次)为试验变量进行混凝土单轴受压试验,研究硫酸盐冻融后沙漠砂混凝土质量、动弹性模量、轴心抗压强度、峰值应变、弹性模量及损伤等的变化规律;结合X射线衍射(XRD)、扫描电子显微镜(SEM)试验分析硫酸盐冻融环境下沙漠砂混凝土的劣化机理。试验结果表明:冻融循环初期,硫酸盐冻融环境下混凝土损伤较小。随着冻融循环次数的增加,混凝土性能劣化加剧。在质量分数为7%的Na_(2)SO_(4)溶液中,冻融后混凝土质量、动弹模量、抗压强度、弹性模量降低幅度最大。沙漠砂替代率由0%增大至40%时,硫酸盐冻融环境下混凝土抗冻性能增强。基于Lemaitre应变等价性原理与连续损伤理论,建立硫酸盐冻融环境下沙漠砂混凝土损伤本构关系。In order to investigate the frost resistance and mechanical properties deteriorationlaw of desert sand concrete(DSC)under sulfate freeze-thaw environment,the uniaxial compression tests of concrete were carried out with desert sand replacement rate(DSRR,0%,20%,and 40%),sulfate solution mass fractions(3%,5%,and 7%),and the number of freeze-thaw cycles(0,25,50,75,100,and 125)as test variables.The variation laws of mass,dynamic elastic modulus,axial compressive strength,peak strain,elastic modulus,and damage of DSC were analyzed.The deterioration mechanism of DSC under sulfate freeze-thaw environment was further investigated by combining X-ray diffraction(XRD)and scanning electron microscope(SEM)tests.The test results showed that the damage of concrete after salt freezing cycles was small at early stage of freeze-thaw cycle,and then the performance deterioration of DSC increased with the increase of the number of freeze-thaw cycles.The mass,dynamic elastic modulus,compressive strength and elastic modulus of DSC after freeze-thawing decreases the most when the mass fraction of the sodium sulfate solution was equal to 7%.The frost resistance of concrete in sulfate freeze-thaw environments gradually increased as the DSRR increase from 0%to 40%.The constitutive relationship of DSC in a sulfate freeze-thaw environment was established based on the Lemaitre assumption of strain equivalence and continuum damage theory.

关 键 词：沙漠砂混凝土 硫酸盐冻融 应力-应变全曲线 WEIBULL分布 损伤本构关系 微观分析 

分 类 号：TU528[建筑科学—建筑技术科学]