聚丙烯纤维增强陶瓷模型石膏性能及机理研究

Study on Performance Improving and Mechanism of Model- gypsum by Polypropylene Fiber

系统研究了聚丙烯纤维体积掺量(V c)及长径比(l/d)对陶瓷模型石膏工作性能、力学行为、软化系数、弯曲韧性及吸水性能的影响。研究表明:l/d600,V c0.88 kg/m3范围内石膏浆体工作性能良好,长径比、掺量增加,浆体流动性变差,凝结时间小幅缩短;石膏硬化体力学性能受纤维影响显著,长径比、掺量增大,软化系数、弯曲韧性增强;抗折强度随纤维长径比增大而降低,l/d600时,掺量增加,抗折强度呈抛物线变化,继续增大长径比,强度逐渐降低。最佳纤维参数为l/d=400,V c=0.88 kg/m3。SEM及孔结构微观机理分析表明:聚丙烯纤维综合改善模型石膏性能效果显著,纤维与石膏界面结合强度及在石膏基体中的分散程度是影响纤维-石膏复合材料性能的主要因素。

The effects of l/d and Vc of polypropylene fiber on the working performance, mechanical behavior and water absorption of mod- el-gypsum were presented. The result showed that when the l/d 〈600 and Vc 〈0.88 kg/m3 ,fiber had little influence on the fluidity of gypsum slurry, and the setting time was slightly shortened by the increasing of Vo and l/d of fiber. The mechanical properties of fiber-gyp- sum composite were significantly influenced by the change of l/d and Vc. Coefficient of softness and flexural toughness grew stronger with the increase of l/d and Ve. Flexural strength decreased as parabola with the increase of l/d. The best parameter of polypropylene fi- ber was d = 400 and Ve = O. 88 kg/m3. SEM indicated that polypropylene takes advantages on the improvement of model-gypsum proper- ties. The most influence factors to composite are interface bounding of fiber-gypsum and the degree of scatter of fiber in the compound.