硫酸盐-干湿循环作用下沙漠砂混凝土耐久性分析  

Durability analysis of desert sand concrete under sulfate dry-wet cycles

作　　者：段欣池 李志强[1] 周阳[1,3] 李刚 王凌霄[2] DUAN Xinchi;LI Zhiqiang;ZHOU Yang;LI Gang;WANG Lingxiao(College of Water Conservancy and Architectural Engineering,Shihezi University,Shihezi 832003,China;Water Conservancy and Hydropower Engineering Group Co.,Ltd.,of XPCC,Urumqi 830011,China;Xinjiang Tianshan Cement Co.,Ltd.,Urumqi 830013,China)

机构地区：[1]石河子大学水利建筑工程学院,新疆石河子832003 [2]新疆兵团水利水电工程集团有限公司,新疆乌鲁木齐830011 [3]新疆天山水泥股份有限公司,新疆乌鲁木齐830013

出　　处：《混凝土》2025年第2期149-154,161,共7页Concrete

基　　金：国家自然科学基金(52268034,52168064);兵团科技创新人才计划项目(2021CB043);兵团科技计划项目(2024AA007);八师重点科技攻关项目(2022GY01)。

摘　　要：为研究硫酸盐侵蚀环境下沙漠砂混凝土的耐久性能,对沙漠砂混凝土试件进行了硫酸盐-干湿循环试验,以有效孔隙率、抗压强度、劈裂抗拉强度、相对硫酸根离子含量作为评价指标,结合SEM微观扫描电镜、X射线单晶衍射,探究了硫酸盐侵蚀环境下沙漠砂混凝土的劣化规律及机理并建立力学性能退化模型。结果表明:沙漠砂不改变混凝土的水化反应,但增加沙漠砂替代率能够提高Ca(OH)_(2)的消耗量与C-S-H的生成量,从而降低混凝土有效孔隙率,抑制混凝土内部初始裂缝产生,减弱混凝土在硫酸盐侵蚀环境下的抗压强度退化。沙漠砂替代率为40%的混凝土具有优良的抗硫酸盐侵蚀性能,经历150次硫酸盐-干湿循环后,有效孔隙率上升40.58%,抗压强度降低7.06%,0~4 mm深度下的硫酸根离子含量为0.720%,各项指标优于普通混凝土。To investigate the durability of desert sand concrete in sulfate erosion environments,desert sand concrete specimens were subjected to sulfate dry-wet cycle tests.The effective porosity,compressive strength,split tensile strength and relative sulfate ion content were evaluated as performance indicators.Combined with SEM(scanning electron microscope)and X-ray diffraction phase analysis,the deterioration law and mechanism of desert sand concrete under sulfate erosion conditions were explored,and a mechanical performance degradation model was established.The results show that desert sand does not alter the hydration reaction of concrete,but increasing the replacement rate of desert sand can increase the consumption of Ca(OH)_(2)and the generation of C-S-H,thereby reduce the effective porosity of concrete,restrain the initiation of internal cracks,and mitigate the compressive strength degradation of concrete in a sulfate erosion environment.Concrete with a 40%substitution rate of desert sand exhibits excellent resistance to sulfate erosion.After 150 times sulfate dry-wet cycles,the effective porosity increases by 40.58%,the compressive strength decreases by 7.06%,and the increase in sulfate ion content at a depth from 0 mm to 4 mm is 0.720%.All performance indicators are superior to those of ordinary concrete.

关 键 词：沙漠砂混凝土 硫酸盐侵蚀 干湿循环 耐久性能 

分 类 号：TU528.01[建筑科学—建筑技术科学]