为探究纤维石膏基胶凝材料的耐久性能，本试验将高强石膏、粉煤灰和矿渣按照44∶34∶22的比例，通过掺杂聚丙烯纤维和苎麻纤维制成纤维石膏基胶凝材料，使用甲基硅酸钠对纤维石膏基胶凝材料进行防水处理，探究在H₂SO₄或NaOH腐蚀与冻融耦合作用下，冻融5、15、25、45、90 d对纤维石膏基胶凝材料软化性能、吸水率和质量损失率的影响。对纤维石膏基胶凝材料进行冻融应变检测，抗折及抗压强度检测，工业计算机断层扫描（computed tomography, CT）检测。结果表明：纤维可以减少石膏基胶凝材料在冻融时的弹性和塑性变形；在酸碱腐蚀与冻融耦合作用下，NaOH比H₂SO₄对纤维石膏基胶凝材料的损伤更大；使用浸泡甲基硅酸钠作防水处理的纤维石膏基胶凝材料，经过90 d冻融后，对比不做防水处理的试件，提高了0.28和0.13的抗折和抗压软化系数，降低了1.56%和9.52%的吸水率和质量损失率；随着冻融次数增加，试件孔隙开展仍以小孔为主，裂隙直径主要为0.1 ~2 mm。

In order to investigate the durability of fiber gypsum-based cementation material, a composite material was prepared by incorporating polypropylene and ramie fibers into high-strength gypsum, fly ash, and slag in a ratio of 44∶34∶22. Sodium methylsilicate was utilized for waterproofing the fiber gypsum-based cementitious material, and the effects of freeze-thaw cycles on its softening property, water absorption, and mass loss were studied after 5, 15, 25, 45, and 90 days under the combined action of H₂SO₄ or NaOH corrosion and freeze-thaw. Freeze-thaw strain testing, flexural and compressive strength testing, as well as industrial computed tomography(CT) scanning were conducted. The results indicate that fibers can mitigate both elastic and plastic deformation of the gypsum-based cementitious material during freeze-thaw cycles. Furthermore, under the combined effect of acid-base corrosion and freeze-thaw cycles, NaOH causes greater damage than H₂SO₄ does. After undergoing 90 days of freeze-thaw cycling with sodium methylsilicate treatment applied to it, the flexural and compressive softening coefficients increase by 0.28 and 0.13 respectively compared to specimens without waterproofing; meanwhile water absorption rates decrease by 1.56% while mass loss rates decreased by 9.52%. As freezing-and thawing times increase, pore development in specimens is still dominated by small holes, and crack diameters are mainly between 0.1 ~2 mm.