镁盐-硫酸盐内外源耦合作用下现浇玄武岩纤维混凝土抗腐蚀试验  

Corrosion resistance test of cast-in-place basalt fiber reinforced concrete under the coupling effect of internal and external magnesium salt sulfate

作　　者：王流鑫 王成[1,2] 葛广华[1] 宋明鸿 周俊尧 WANG Liuxin;WANG Cheng;GE Guanghua;SONG Minghong;ZHOU Junyao(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11期180-186,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);国家自然科学基金(52168035);新疆生产建设兵团区域创新引导计划项目(2018BB045)。

摘　　要：将不同体积掺量(0、0.1%、0.3%、0.5%)的短切玄武岩纤维和拌和水质量3%的无水MgSO4试剂掺入混凝土中,开展现浇玄武岩纤维混凝土在不同浓度(0、3%、5%、10%)Na2SO4溶液中的内外源耦合腐蚀试验,分析试件立方体抗压强度、相对动弹性模量、质量损失率的变化规律和SO42-在混凝土中的扩散分布特征。研究结果表明:(1)玄武岩纤维的桥接作用能有效提高现浇混凝土的立方体抗压强度,减少混凝土内部微裂缝的生成与扩展,抑制腐蚀产物引起的膨胀破坏,提升现浇混凝土的抗腐蚀性能。(2)在相同的腐蚀龄期,体积掺量为0.3%试件的立方体抗压强度最高,质量损失率最小,相对动弹性模量波动幅度最小,抗腐蚀能力最强。(3)镁盐-硫酸盐内外源耦合作用下,现浇玄武岩纤维混凝土的腐蚀产物主要是钙矾石(AFt)和石膏。而且,M组试件中Ca(OH)2的结晶度较差,消耗速率明显比M3BF组试件中的快。研究成果可为现浇玄武岩纤维混凝土在强盐渍土地区的工程应用提供参考。To explore the variations in the compressive strength,relative dynamic modulus,and mass loss rate of cast-in-place basalt fiber reinforced concrete cubes,as well as the diffusion distribution characteristics of SO_(2)in the specimens,different volume proportions(0,0.1%,0.3%,0.5%)of short-cut basalt fibers and 3%by mass of anhydrous MgSO4 were mixed into the concrete.Subsequently,cor ro-sion tests were conducted under the coupling effect of different concentrations(0,3%,5%,10%)of NaSO4 solution.The research results indicate that:(1)the bridging effect of basalt fibers can improve the cubic compressive strength of cast-in-place concrete effectively.It restrained the generation and expansion of micro cracks inside the concrete and suppressed the expansion damage caused by corrosion products.Therefore,the corrosion resistance of cast-in-place concrete is improved.(2)For the same corrosion aging period,the specimens with a volume proportion of 0.3%has the highest cubic compressive strength the lowest mass loss rate,the smallest fluctuation of the relative dynamic elastic modulus,and the strongest corrosion resistance.(3)The corrosion products of cast-in-place basalt fiber concrete are ettringite(AFt)and gypsumunder the coupling effect of internal and external magnesium salt sulfate.Moreover,the crystallinity of Ca(OH)_(2)in the M group specimens is poor,and the consumption rate is significantly faster than that in the M3BF group specimens.The research results can provide reference for the engineering application of cast-in-place basalt fiber reinforced concrete in areas with strong saline soil.

关 键 词：玄武岩纤维 现浇混凝土 内外源耦合腐蚀 抗压强度 耐久性 

分 类 号：TU528.572[建筑科学—建筑技术科学]