聚甲醛纤维对自密实混凝土抗氯离子渗透性能的影响  

Effect of Polyoxymethylene Fiber on Chloride Ion Penetration Resistance of Self-Compacting Concrete

作　　者：刘恒 贺晶晶 冯兴国[1] 崔海鹏 LIU Heng;HE Jing-jing;FENG Xing-guo;CUI Hai-peng(College of Harbor,Coastal and Offshore Engineering,Hohai University,Nanjing 210013,Jiangsu Province,China;Northwest Engineering Corporation Limited,Xi'an 710100,Shaanxi Province,China)

机构地区：[1]河海大学港口海岸与近海工程学院,江苏南京210013 [2]中国电建集团西北勘测设计研究院有限公司,陕西西安710100

出　　处：《中国农村水利水电》2025年第4期102-108,116,共8页China Rural Water and Hydropower

基　　金：国家自然科学基金资助项目(5207090694);陕西省自然科学基础研究计划资助项目(2021JQ-983)。

摘　　要：分析聚甲醛(POM)纤维几何特性、纤维掺量(共计28组)对自密实混凝土(SCC)的力学性能和抗氯离子性能影响规律,以电通量值、电流-时间曲线、氯离子渗透深度及氯离子扩散系数作为SCC抗氯离子渗透性能的评价指标。研究表明:在保持基准组配合比不变的条件下,POM纤维掺量不宜超过1.6 kg/m^(3),纤维掺量过高会导致SCC整体性能下降。6 mm及12 mm圆柱状POM纤维在掺量为1.6 kg/m^(3)左右时,抗压强度及抗氯离子渗透性能最佳,较素SCC的28 d强度提高3.6%,氯离子渗透性能等级由中转为低;以1.6 kg/m^(3)掺量的12 mm扁平状POM纤维和6 mm圆柱状POM纤维混杂的SCC劈裂抗拉强度最高,较素SCC的28 d强度提高14.52%,掺入POM纤维能够提高SCC的力学性能及抗氯离子渗透性。SCC的氯离子扩散系数和电通量之间有着良好的线性关系,且二者与渗透性和耐久性之间关系紧密。引入POM能够改善SCC的微观结构,优化内部孔隙,宏观上表现为力学性能及抗氯离子渗透性能提升。研究结论可为POM纤维自密实混凝土工程应用提供参考。The effects of polyoxymethylene(POM)fiber geometric characteristics and fiber content(28 groups in total)on the mechanical properties and chloride ion resistance of self-compacting concrete(SCC)were analyzed.The electrical flux,current-time curve,chloride ion penetration depth and chloride ion diffusion coefficient were used as evaluation indexes of SCC's chloride ion penetration resistance.The research shows that the POM fiber content should not exceed 1.6 kg/m^(3) under the condition of keeping the mixture ratio of the reference group unchanged,and too high fiber content will lead to the decline of the overall performance of SCC.When the dosage of 6mm and 12 mm cylindrical POM fiber is about 1.6 kg/m^(3),the compressive strength and chloride ion permeability are the best,which is 3.6%higher than that of plain SCC at 28 d,and the chloride ion permeability changes from medium to low.The splitting tensile strength of SCC mixed with 12mm flat POM fiber and 6mm cylindrical POM fiber with the dosage of 1.6 kg/m^(3) is the highest,which is 14.52% higher than that of plain SCC at 28 d.Adding POM fiber can improve the mechanical properties and chloride ion penetration resistance of SCC.There is a good linear relationship between chloride diffusion coefficient and electric flux of SCC,and they are closely related to permeability and durability.The introduction of POM can improve the microstructure of SCC,optimize the internal pores,and improve the mechanical properties and chloride ion penetration resistance on the macro level.The research conclusion can provide references for the engineering application of POM fiber self-compacting concrete.

关 键 词：自密实混凝土 聚甲醛纤维 电通量 氯离子渗透深度 氯离子扩散系数 

分 类 号：TV431.4[水利工程—水工结构工程]