掺废弃陶瓷纤维增强水泥基复合材料抗冻性能

Enhanced Frost Resistance in Composite Materials Through Incorporating Waste Ceramic Fiber⁃Reinforced Cement

采用陶瓷粉替代一部分水泥,陶瓷砂替代普通河砂,在水泥基材料中掺入不同体积掺量的聚乙烯醇(Polyvinyl Alcohol,PVA)纤维,制成掺入PVA纤维和陶瓷粉的水泥基复合材料砂浆试件。通过冻融循环试验分析质量损失率、相对动弹性模量的变化,并通过电化学阻抗测试和扫描电子显微镜观察研究砂浆试件的冻融损伤规律。结果表明:陶瓷粉中SiO_(2)和Al_(2)O_(3)含量远大于水泥中相应含量,且粒径小于20μm的颗粒占82.3%,火山灰效应和微集料效应可改善试件的密实度,提升复合材料的抗冻性能;PVA纤维掺量为2.2%,陶瓷粉掺量为30%,冻融循环100次时砂浆试件质量损失率最小,相对动弹性模量最大,连续导电路径电阻最大,冻融损伤程度最小;纤维和基体的接触面是该复合材料抗冻薄弱部位。

This study explores the integration of ceramic powder and polyvinyl alcohol(PVA)fibers into cement-based materials to improve frost resistance.By partially replacing cement with ceramic powder and substituting conventional river sand with ceramic sand,mortar specimens are created and subjected to freeze-thaw cycling tests.Analysis of changes in mass loss rates and relative dynamic elastic modulus,along with investigations using electrochemical impedance testing and scanning electron microscopy,reveal key findings.Ceramic powder,with significantly higher SiO_(2) and Al_(2)O_(3) content than cement,and particle diameter smaller than 20μm(constituting 82.3%),enhances specimen density through volcanic ash and microaggregate effects,thereby boosting frost resistance.Optimal results are achieved with 2.2%PVA fiber content and 30%ceramic powder content,resulting in minimal mass loss,maximum relative dynamic elastic modulus,highest continuous conductive path resistance,and minimal freeze-thaw damage after 100 cycles.The study identifies the fiber-matrix interface as the vulnerable aspect impacting the frost resistance of this composite material.