硫酸盐侵蚀下现浇混凝土耐腐蚀及力学性能试验  

Study on corrosion resistance and mechanical properties of cast-in-place concrete under sulfate attack

作　　者：黎飞帆 王成[1,2] 葛广华[1] 王锦钰 刘欣鹏 LI Feifan;WANG Cheng;GE Guanghua;WANG Jinyu;LIU Xinpeng(School of Hydraulic and Architectural Engineering,Tarim University,Alar 843300,China;Southern Xinjiang Geotechnical Engineering Research Center,Tarim University,Alar 843300,China)

机构地区：[1]塔里木大学水利与建筑工程学院,新疆阿拉尔843300 [2]塔里木大学南疆岩土工程研究中心,新疆阿拉尔843300

出　　处：《混凝土》2024年第5期57-63,共7页Concrete

基　　金：新疆生产建设兵团重点领域科技攻关计划项目(2019AB016);新疆生产建设兵团区域创新引导计划项目(2018BB045);国家自然科学基金(52168035)。

摘　　要：为了提高强硫酸盐渍土地区现浇混凝土的抗腐蚀性能,开展了煅烧偏高岭土等质量替代水泥比例为0、5%、15%、25%、50%的现浇混凝土试件,分别在清水、5%Na_(2)SO_(4)、10%Na_(2)SO_(4)和10%Na_(2)SO_(4)+10%NaCl溶液中的长期浸泡试验,分析了试件在1 d、3 d、7 d、14 d、28 d和90 d龄期时的抗折强度、抗压强度、相对动弹性模量、质量损失率、体积膨胀率和有效孔隙率的变化规律。研究结果表明:(1)掺入煅烧偏高岭土可提高现浇混凝土的抗折强度、抗压强度和抗腐蚀性能,掺量为25%时,试件的抗折强度和抗压强度最高,相对动弹性模量变化最稳定,抗硫酸盐侵蚀性能最好。(2)煅烧偏高岭土可以改善混凝土的内部孔隙结构,降低现浇混凝土的有效孔隙率和质量损失率,使试件的体积稳定性明显提高。研究成果可为煅烧偏高岭土提升现浇混凝土在强硫酸盐渍土地区的工程应用提供一定的理论基础。To improve the corrosion resistance of cast-in-place concrete in regions with potent sulfate-saline soils,calcined metakaolin was used to replace 0,5%,15%,25%,and 50%cement.Prolonged immersion tests were conducted in pure water,5%Na_(2)SO_(4),10%NaSO_(4),and 10%NaSO_(4)+10%NaCl solution.The flexural strength,compressive strength,relative dynamic modulus of elasticity,mass loss rate,volumetric expansion rate,and effective porosity of the specimens at 1 d,3 d,7 d,14 d,28 d,and 90 d of age were examined.The results show that(1)The addition of calcined metakaolin improves the flexural strength,compressive strength,and corrosion resistance of cast-in-place concrete.When the content of calcined metakaolin is 25%,the specimens exhibit optimal flexural and compressive strength,the most stable relative dynamic modulus of elasticity,and superior sulfate attack resistance.(2)Calcined metakaolin effectively reduces the effective porosity and mass loss rate of cast-in-place concrete while significantly improving the volumetric stability of the specimens.These research results can offer a theoretical foundation for the engineering application of calcined metakaolin in elevating cast-in-place concrete performance within sulfate-saline soil environments.

关 键 词：硫酸盐侵蚀 现浇混凝土 煅烧偏高岭土 耐久性 力学性能 

分 类 号：TU528.01[建筑科学—建筑技术科学]