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广泛应用石棉纤维作为石棉水泥制品的增强材料已有很久的历史。由于高品位长纤维石棉资源的耗尽和石棉纤维对人体健康带来的隐患,近年来,人们十分期望发展能代替石棉纤维的代用纤维,代用纤维显示出很好的发展前景,聚合物纤维也被考虑为这样的代用纤维。本研究的目的是弄清聚合物纤维增强水泥强度性能。本论文中,用硅灰和减水剂使聚合物纤维在水泥砂浆中均匀分散。用聚酰胺、聚丙烯腈和聚乙烯醇纤维制备聚合物纤维增强水泥,其水灰比为30％、硅灰比为40％、减水剂用量为水泥重量的4％、纤维的体积含量为0,2.5,和5.0％。用聚合物纤维增强水泥制作棱柱体试件的尺寸为40×40×160mm,试件首先在温度20℃、相对湿度80％的湿空气中养护一天,然后在60℃水中养护六天。养护后的试件进行抗弯强度试验,记录弯曲荷载—挠度曲线以计算弯曲韧性及等效弯曲强度。将经抗弯试验破坏后的部分试件进行抗压强度试验,从试验结果得到的结论概括如下: (1)除聚乙烯醇纤维增强水泥以外,聚合物纤维增强水泥的强度性能如抗弯和抗压强度、弯曲韧性和等效弯曲强度随纤维含量的增加有显著的改善; (2)聚乙烯醇纤维增强材料对聚合物纤维增强水泥的强度性能几乎没有什么影响; (3)除聚乙烯醇纤维外,聚酰胺和聚丙烯腈等聚合物纤维可用作石棉纤维的代用纤维。
Widespread use of asbestos fibers as reinforcement for asbestos cement products has a long history. Due to the exhaustion of high-grade long-fiber asbestos resources and hidden dangers of asbestos fiber to human health, in recent years, people are very much looking forward to the development of substitute fibers that can replace asbestos fibers, and alternative fibers have shown promising development prospects. Considered as such substitute fibers. The purpose of this study was to clarify the strength properties of polymer fiber reinforced cement. In this paper, silica fume and water-reducing agent are used to make the polymer fiber evenly dispersed in the cement mortar. Preparation of polymer fiber reinforced cement with polyamide, polyacrylonitrile and polyvinyl alcohol fibers, with a water-cement ratio of 30%, a silica fume ratio of 40%, a water-reducing agent in an amount of 4% by weight of cement, and a fiber volume content of 0, 2.5, and 5.0%. The dimensions of prismatic specimens made of polymer fiber reinforced cement were 40×40×160 mm, and the specimens were first cured in a humidified air at a temperature of 20° C. and a relative humidity of 80% for one day and then cured in water at 60° C. for six days. The cured specimens were subjected to bending strength tests and the bending load-deflection curves were recorded to calculate the bending toughness and the equivalent bending strength. Some of the specimens that have been destroyed by the flexural test are subjected to a compressive strength test. The conclusions obtained from the test results are summarized as follows: (1) In addition to polyvinyl alcohol fiber-reinforced cement, the strength properties of the polymer fiber-reinforced cement such as bending and Compressive strength, flexural toughness and equivalent flexural strength are significantly improved with the increase of fiber content; (2) Polyvinyl alcohol fiber reinforced material has almost no effect on the strength properties of polymer fiber reinforced cement; (3) In addition to polyethylene Besides alcohol fibers, polymer fibers such as polyamide and polyacrylonitrile can be used as substitute fibers for asbestos fibers.