硫酸盐侵蚀下混杂纤维/橡胶混凝土力学性能及微观结构  

Mechanical properties and microstructure of hybrid fiber reinforced rubber concrete under sulfate attack

作　　者：刘雨姗 庞建勇[1] LIU Yushan;PANG Jianyong(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan 232001,China)

机构地区：[1]安徽理工大学土木建筑学院,淮南232001

出　　处：《复合材料学报》2024年第4期2055-2064,共10页Acta Materiae Compositae Sinica

基　　金：安徽理工大学高层次引进人才科研启动基金(2022yjrc77)。

摘　　要：为研究混杂纤维/橡胶混凝土(HF/RC)的抗硫酸盐侵蚀性能,对比分析硫酸盐环境下干湿循环240次内,普通混凝土(NC)和HF/RC的表观现象、质量损失、超声参数、抗压强度损失等性能指标劣化过程,采用SEM及XRD微观表征手段分析硫酸盐/干湿循环前后试件微观形貌及物相组成。结果表明:随硫酸盐/干湿循环次数增加,NC、HF/RC试件的质量、抗压强度呈先增后减的趋势,超声参数与抗压强度、耐蚀系数具有密切相关性;侵蚀初期SO_(4)^(2−)与胶凝物质反应填充原生孔隙,基体密实度提高。侵蚀过程胶凝材料不断被消耗,基体在硫酸钠反复结晶的物理侵蚀及硫酸盐化学侵蚀的共同作用下出现空隙和孔洞。但橡胶颗粒和混杂纤维可阻断裂缝扩展继而减缓SO_(4)^(2−)扩散,抑制膨胀性产物生成,延缓结晶应力诱发的表层裂纹发育。硫酸盐侵蚀各阶段HF/RC的劣化程度均优于NC,经240次硫酸盐/干湿循环后,NC、HF/RC的耐蚀系数分别为69.00%、78.87%。To study the sulfate resistance performance of hybrid fiber reinforced rubber concrete(HF/RC),the apparent phenomena,mass loss,ultrasonic parameters and compressive strength of normal concrete(NC)and HF/RC were analyzed during 240 dry-wet cycles under sulfate environment.SEM and XRD were used to analyze the microstructure and phase composition of the specimen under sulfate attack.The results show that with the increase of dry-wet cycles,the mass and compressive strength of NC and HF/RC specimens increase firstly and then decrease.Ultrasonic parameters are closely related to compressive strength and corrosion resistance coefficient.In the early stage of erosion,SO_(4)^(2−)reacts with the cementitious material to fill the original pores,and the compactness of the matrix is improved.With the continuous consumption of cementitious materials,voids and pores appear in the matrix due to the physical erosion caused by repeated crystallization of sodium sulfate and the chemical erosion caused by sulfate.Rubber particles and hybrid fibers delay the emergence and development of crack and slow down SO_(4)^(2−)diffusion.The generation of expansive products is inhibited,and the development of surface cracks induced by crystallization stress is delayed.The damage degree of HF/RC in each stages of sulfate erosion is better than that of NC.After 240 dry-wet cycles,the corrosion resistance coefficient of NC is 69.00%while that of HF/RC is 78.87%.

关 键 词：硫酸盐环境 橡胶混凝土 玄武岩纤维 聚乙烯醇纤维 干湿循环 微观结构 

分 类 号：TB332[一般工业技术—材料科学与工程] TU278.3[建筑科学—建筑设计及理论]