SO_(2)和CO_(2)共同作用下混凝土性能劣化研究  

Performance Deterioration of Concrete Under the Combined Action of SO_(2)and CO_(2)

作　　者：牛荻涛[1,2] 杨瑞希 吕瑶[1] 孙杏杏 曹志远 吴鸿渠 NIU Ditao;YANG Ruixi;LYU Yao;SUN Xingxing;CAO Zhiyuan;WU Hongqu(School of Civil Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;State Key Laboratory of Green Building in Western China,Xi’an University of Architecture and Technology,Xi’an 710055,China)

机构地区：[1]西安建筑科技大学土木工程学院,西安710055 [2]西安建筑科技大学省部共建西部绿色建筑国家重点实验室,西安710055

出　　处：《材料导报》2025年第5期148-154,共7页Materials Reports

基　　金：国家自然科学基金(52078413)。

摘　　要：在电力、机械、冶金和化工等行业,工业生产过程中排放大量SO_(2)和CO_(2)气体,导致混凝土结构耐久性问题突出,严重缩短了混凝土结构的使用寿命。本工作研究了SO_(2)与CO_(2)共同作用下混凝土中性化深度、相对动弹性模量以及损伤层厚度的变化规律。采用扫描电镜(SEM)、X射线衍射仪(XRD)和核磁共振仪(NMR)测试了混凝土的微观形貌、物相组成和孔隙结构,揭示了SO_(2)与CO_(2)共同作用下混凝土的腐蚀机理。结果表明:混凝土中性化深度和损伤层厚度均呈“三阶段”增长趋势,水胶比为0.57的混凝土在第35次循环后中性化深度和损伤层厚度分别达到20.55 mm和10.93 mm;相对动弹性模量呈先增大后下降的趋势,且随水胶比的增大而增大。SO_(2)和CO_(2)共同作用下,混凝土腐蚀的最终产物为石膏。相较于未腐蚀混凝土,膨胀性产物石膏的生成使得中性化混凝土孔隙率增大,水胶比为0.37、0.47、0.57的混凝土在第35次腐蚀循环后孔隙率分别增大了0.19%、0.18%、0.15%,且混凝土孔结构呈小孔向中孔、中孔向大孔发展的趋势。During the industrial production processes of electricity,machinery,metallurgy and chemical industries,a large amount of SO_(2) and CO_(2) gases are emitted,which lead to the problem of durability of concrete structures and seriously reduce the service life of concrete structures.In this work,the changing patterns of neutralization depth,relative dynamic elastic modulus and damage layer thickness of concrete under the combined action of SO_(2) and CO_(2) were investigated.The microscopic morphology,phase composition and pore structure of concrete,both before and after corrosion,were tested by scanning electron microscopy(SEM),X-ray diffraction(XRD)and nuclear magnetic resonance(NMR),and the corro-sion mechanism of concrete under the combined action of SO_(2) and CO_(2) was revealed.The results show that both the neutralization depth and the damage layer thickness show a distinctive“three-stage”growth trend.For concrete with a water-binder ratio of 0.57,the neutralization depth and damage layer thickness reach 20.55 mm and 10.93 mm,respectively,after the 35th corrosion cycle.The relative dynamic elastic modulus in-creases first and then decrease,and it increases with the increase of water-binder ratios.Under the combined action of SO_(2) and CO_(2),the final product of concrete corrosion is gypsum.Compared with uncorroded concrete,the expansive gypsum formated increases the porosity of neutra-lized concrete,and the porosity of concrete with water-cement ratio of 0.37,0.47 and 0.57 increases by 0.19%,0.18%and 0.15%respectively after the 35th corrosion cycle,and the pore structure of concrete tends to develop from small pores to medium pores and from medium pores to large pores.

关 键 词：混凝土 二氧化碳 二氧化硫 性能劣化 中性化深度 腐蚀机理 

分 类 号：TU528[建筑科学—建筑技术科学]