不同尺度纤维复合增强水泥基材料的抗氯离子渗透性能

Chloride ion resistance of multi-scale fiber reinforced cementitious composites

为研究不同尺度纤维复合增强水泥基材料的抗氯离子渗透性能,对单掺和复掺碳酸钙晶须、聚乙烯醇(PVA)纤维的水泥基材料分别进行电通量试验、电镜扫描观测及基本力学性能试验,分析不同纤维尺度、掺量及复合比例对水泥基材料抗氯离子渗透性能和基本力学性能的影响规律,并基于试验结果给出了多纤维复合增强水泥基材料的氯离子侵蚀深度计算模型。结果表明,不同尺度纤维可在不同结构层次上发挥对水泥基材料的增强作用,使得多纤维复合增强水泥基材料的抗氯离子渗透性能明显优于单一纤维增强水泥基材料;多纤维复合材料的抗压强度与氯离子侵蚀深度及电通量大致呈反比例关系;当复合材料的抗压强度提高13.6%时,其氯离子侵蚀深度和总电通量则分别降低39.1%和44.7%;建立的氯离子侵蚀深度计算模型,可用于多纤维复合增强水泥基材料的抗氯离子渗透和侵蚀性能评估。

The electric flux tests,scanning electron microscope and mechanical tests were carried out respectively on cementitious composites with single mixing and compound mixing CaCO3 whisker and PVA fiber to investigate chloride ion resistance of multi-scale fiber reinforced cementitious composites.The effects and mechanisms of different fiber sizes,amount of admixture and mixing ratios on the chloride ion resistance and basic mechanical properties of cementitious composites were analyzed.In addition,the calculation method of the depth of chloride ion erosion was proposed.The results showed that different types of fibers can enhance cementitious composites at different structural levels,and the chloride ion resistance of multi-scale fiber reinforced cementitious composites is much better than that of single fiber reinforced cementitious composites.The compressive strength of composites is inversely proportional to the depth of chloride ion erosion and the electric flux.When the compressive strength of the composite was increased by 13.6%,the depth of chloride ion erosion and the electric flux were decreased by 39.1% and 44.7%,respectively.Based on the experimental data,a calculation model of chloride ion erosion depth considering the influence of compressive strength is established,which can be used to evaluate the chloride ion penetration and erosion resistance of cement-based materials reinforced by multi-fiber composite.