不同机制砂混凝土耐硫酸盐侵蚀特性  

Sulfate Corrosion Resistance of Different Manufactured Sand Concretes

作　　者：王发平 张硕文 关博文[2] 贾治勋 WANG Fa-ping;ZHANG Shuo-wen;GUAN Bo-wen;JIA Zhi-xun(Qinghai Transport Holding Group Co.,Ltd.,Xining Qinghai 810001,China;School of Materials Science and Engineering,Chang’an University,Xi’an Shaanxi 710064,China)

机构地区：[1]青海省交通控股集团有限公司,青海西宁810001 [2]长安大学材料科学与工程学院,陕西西安710064

出　　处：《公路交通科技》2023年第8期43-50,共8页Journal of Highway and Transportation Research and Development

基　　金：青海省自然科学基金项目(2021-ZJ-765);陕西省自然科学基金项目(2022JM-209)。

摘　　要：为了研究机制砂混凝土抗硫酸盐侵蚀性能,分别使用天然河砂以及石灰石、玄武岩、花岗岩这3种岩性机制砂制备了混凝土试件。进行了硫酸盐侵蚀试验、质量损失试验、立方体抗压强度测试和硫酸盐含量滴定测试,对试件质量损失、抗压强度、耐蚀系数和硫酸根离子分布进行了研究,并利用CT技术比对了不同混凝土在硫酸盐侵蚀后表面形貌缺失的差异。结果表明:各种混凝土在养护阶段的抗压强度差异不大;在硫酸盐侵蚀循环过程中混凝土的质量与强度均呈现先增大后减小的趋势,且强度变化滞后于质量变化;在干湿循环次数小于100次时,硫酸盐浓度的增大会加速混凝土质量和强度的升高;各种混凝土耐蚀系数的变化规律与抗压强度变化规律保持一致,均表明硫酸盐浓度较大时会加速混凝土的劣化,且使其性能更早劣化;在3%硫酸盐浓度侵蚀条件下干湿循环100次后机制砂混凝土的耐蚀系数比天然河砂混凝土提高了3%~5%;在相同硫酸盐浓度、干湿循环次数和侵蚀深度下,机制砂混凝土的硫酸根离子浓度略低于天然河砂混凝土,CT图像表明在相同条件下天然河砂混凝土遭受硫酸盐侵蚀后更易发生脱落并形成裂纹;机制砂可以在一定程度上提高混凝土的耐硫酸盐侵蚀性能,其棱角性和嵌挤结构有助于增强混凝土抗硫酸盐侵蚀性能。In order to study the sulfate corrosion resistance of manufactured sand concrete,the concrete specimens are prepared by using natural river sand and 3 kinds of lithologic manufactured sand,which are limestone,basalt and granite.The mass loss,compressive strength,corrosion resistance coefficient and sulfate ion distribution of the specimens are studied with sulfate corrosion test,mass loss test,cube compressive strength test and sulfate content titration test,and the differences of surface appearance loss of different concretes after sulfate corrosion are compared with CT technology.The result shows that(1)there is little differences of compressive strength among every kind of concrete in curing stage;(2)the mass and strength of the concrete decrease after increasing during the sulfate corrosion cycles,and the variation of strength lags behind that of mass;(3)when the number of dry-wet cycles is less than 100 cycles,the increase of mass and strength of the concrete are accelerated with the increase of sulfate concentration;(4)the variation rule of corrosion resistance coefficient of every kind of concrete is in agreement with that of compressive strength,indicating that the deterioration of concrete will be accelerated when the sulfate concentration is high,and the performance will deteriorate earlier;(5)the corrosion resistance coefficients of manufactured sand concretes increased 3%-5%compared with those of natural river sand concrete after 100 dry-wet cycles under the corrosion by 3%sulfate concentration;(6)under the same sulfate concentration,dry-wet cycles and corrosion depth,the sulfate ion concentrations of manufactured sand concretes are slightly lower than that of natural river sand concrete,and CT images show that natural river sand concrete is more likely to fall off and form cracks after being eroded by sulfate under the same condition;(7)the manufactured sand can improve the sulfate resistance of the concrete to a certain extent,and the angularity and embedded structure of manufactured sand help to en

关 键 词：道路工程 硫酸盐侵蚀 CT技术 机制砂混凝土 岩性 

分 类 号：TU414[建筑科学—岩土工程]