硫酸盐侵蚀对掺钢渣粉PVA纤维增强水泥基复合材料断裂性能影响  

Effect of sulfate corrosion on the fracture properties of PVA fiber reinforced cement-based composite materials with steel slag powder

作　　者：苏骏 范子康 蔡新华[2] SU Jun;FAN Zikang;CAI Xinhua(School of Civil Engineering and Environment,Hubei University of Technology,Wuhan 430068,China;State Key Laboratory of Water Resources&Hydropower Engineering Science,Wuhan University,Wuhan 430072,China)

机构地区：[1]湖北工业大学土木建筑与环境学院,武汉430068 [2]武汉大学水资源与水电工程科学国家重点实验室,武汉430072

出　　处：《复合材料学报》2024年第6期3103-3114,共12页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金面上项目(52178247);湖南省水利科技项目(XSKJ2021000-15)。

摘　　要：为研究固体废料钢渣及硫酸盐溶液侵蚀作用下水泥基复合材料断裂特性,本文设计掺入不同质量分数的钢渣粉制备聚乙烯醇纤维增强水泥基复合材料(PVA/ECC),通过对硫酸盐侵蚀后的预制初始裂缝梁式试件进行三点弯曲性能试验,同时结合掺钢渣粉PVA/ECC在Na2SO4溶液(质量分数为5wt%)中的表观形态和微观结构特征,探究硫酸盐侵蚀对钢渣粉PVA/ECC断裂性能的影响。结果表明:在未受硫酸盐侵蚀钢渣粉掺量为20wt%时,试件起裂荷载、失稳荷载提升效果最优,较未掺钢渣粉试件分别提高约61%、110%;PVA/ECC断裂韧度随侵蚀时间先增大后减小,侵蚀60天到达峰值,120天后S80组劣化最明显,起裂韧度Kini和失稳韧度Kun分别减小了约23%、13%;适量钢渣粉的掺入能有效缓解PVA/ECC的侵蚀损伤,钢渣粉掺量不超过60wt%时在试验研究的龄期范围内材料未出现明显劣化。在此基础上通过Weibull分布模型预测试件耐久性寿命,其中钢渣粉掺量为20wt%的PVA/ECC使用寿命最长,可达到444次左右。In order to study the fracture characteristics of cement-based composite materials under the solid waste steel slag and erosion of sulfate solution,the polyvinyl alcohol fiber reinforced cement-based composite materials(PVA/ECC)were prepared by adding different mass fractions of steel slag powder.Three-point bending performance test was conducted on prefabricated initial crack beam specimens after sulfate erosion.Combined with the apparent morphology and microstructure characteristics of steel slag powder PVA/ECC in Na2SO4 solution(mass fraction of 5wt%),the effect of sulfate corrosion on the fracture performance of steel slag powder PVA/ECC was investigated.The results show that when the content of steel slag powder without sulfate attack is 20wt%,the cracking load and instability load of the specimen are the best,with an increase of about 61%and 110%compared to the specimens without steel slag powder,respectively.The fracture toughness of PVA/ECC first increases and then decreases with erosion time,reaching its peak after 60 days of erosion.After 120 days,the S80 group shows the most obvious degradation,with the initiation toughness$K\mathrm{^{ini}}$and instability toughness${K}^{\mathrm{u}\mathrm{n}}$decreasing by about 23%and 13%,respectively.The addition of an appropriate amount of steel slag powder can effectively alleviate the erosion damage of PVA fiber reinforced cement-based composite materials.When the amount of steel slag powder does not exceed 60wt%,there is no significant deterioration of the material within the age range of the experimental study.On this basis,the durability life of the specimens was predicted using a Weibull distribution model,PVA/ECC with a 20wt%steel slag powder content having the longest service life,reaching around 444 cycles.

关 键 词：PVA纤维 钢渣粉 硫酸盐侵蚀 干湿循环 断裂韧度 耐久性能 

分 类 号：TU528[建筑科学—建筑技术科学] TB332[一般工业技术—材料科学与工程]