有机纤维与聚合物复掺改性水泥砂浆力学性能研究

Study on Mechanical Properties of Organic Fiber and Polymer Composite-Modified Cements Mortar

在固定水灰比为0.35条件下,分别研究了聚酯纤维、聚合物丁苯乳液单掺与复掺时对水泥混凝土抗压抗折强度、折压比的影响。结果表明:单掺聚酯纤维在一定掺量下可以不同程度地提高水泥砂浆的抗压抗折强度,折压比随着聚酯纤维含量的增加呈先减小后增加的趋势;单掺聚合物乳液降低了水泥砂浆的抗压强度,而折压比则随聚合物乳液掺量增加呈现逐步变大的趋势;聚酯纤维与聚合物乳液复掺时,聚合物乳液的掺入使聚酯纤维混凝土的抗压强度出现小幅降低,增强了其抗折强度,提高了其折压比,当纤维体积掺量为0.1%、聚灰比为15%时,聚酯纤维聚合物水泥混凝土的柔性最大;纤维-聚合物复掺能够使其性能得到进一步改善,效果优于两者的单掺效果。并通过扫描电镜探讨了聚酯纤维与聚合物乳液在水泥砂浆中的作用机理,表明两者复掺有效填充了水泥基材料内部的宏观与微观缺陷,提高了界面过渡区的密实程度。

Effect of content of styrene-butadiene latex and polyester fiber on the compressive and flexural strength, and the flexural/compression ratio mechanical properties of cement mortar at fixed water-cement ratio of 0. 35 were investigated. The test results show that addition of a certain volume content of single polyester fiber can im- prove compressive strength and flexural strength of the cement mortar in different degrees, the flexural-compression ratio increased with the increase of polyester fiber content showed a trend of increase after the first reduce. Single- doped polymer emulsion reduces the compressive of cement mortar, and the flexural-eompression ratio shows a gradual increase with increase of polymer emulsion dosage. When polyester fiber and polymer emulsion mixed, compressive strength of polyester fiber concrete shows slightly lower, the flexural strength and flexural-compression ratio are both showing increase. When the fiber volume content is 0.1 ~, and the ratio of polymer is 15 %, flexibility of modified ce- ment concrete is best. Fiber-polymer can further improve its performance, and complex-doped effect is better than sin- gle-doped effect. The enhanced mechanism of polyester fiber and polymer emulsion on cement mortar properties was analyzed by scanning electron microscopy, indicating that the added polyester fiber and polymer emulsion could effec- tively fill the inside of the macro and micro defects, and improve the interfacial transition zone of compaction.