冻融环境下PVA纤维水泥基复合材料断裂性能

针对冻融循环次数对PVA纤维水泥基复合材料断裂性能的影响问题,提出了基于快冻法的三点弯曲试验方法,研究了冻融循环次数对PVA纤维水泥基复合材料的起裂韧度、失稳韧度及断裂能的影响,并对冻融循环后的试件质量及表面现象进行了分析.结果表明:在冻融循环250次后,试件的质量增加1.92%,起裂韧度、失稳韧度、断裂能分别降低了37.2%、51.1%及48.4%;随着冻融循环次数的增加,试件的质量呈现增长趋势,试件表面破坏情况愈发严重,试件的起裂韧度、失稳韧度及断裂能均呈现下降趋势.

Fracture performance of PVA fiber cementitious composites under freeze-thaw cycles

Aiming at the effect of freeze-thaw cycles on the fracture performance of PVA fiber cementitious composites, a three-point bending test method based on the quick freezing method was proposed, the effect of freeze-thaw cycles on the initial fracture toughness, unstable toughness and fracture energy of PVA fiber cementitious composites was studied, and the mass and surface phenomena of specimens after the freeze-thaw cycles were analyzed. The results show that after 250 freeze-thaw cycles, the mass of specimens increases by 1.92%, while the initial fracture toughness, unstable toughness and fracture energy reduce by 37.2%, 51.1% and 48.4% respectively. With increasing the freeze-thaw cycles, the mass of specimens shows an increasing trend, the surface damage of specimens is more serious, and the initial fracture toughness, unstable toughness and fracture energy of specimens show a decreasing trend.