摘要:
由于矿粉/粉煤灰基地质聚合物的韧性较差,本文选用聚乙烯醇纤维和水溶性粉末对其进行增韧改性研究.研究表明:聚乙烯醇水溶性粉末的掺量为0.5%时,抗压和抗折强度分别提高9.6%和25%,可以起到增韧作用,但掺量继续增加会导致力学性能大幅下降;随着聚乙烯醇纤维掺量的不断提高,抗压强度持续降低,抗折强度不断提高,压折比不断降低,当掺量为3%时,抗折强度提高35%,压折比降低35%.结合XRD测试和SEM-EDS分析,研究聚乙烯醇对地质聚合物微观结构的影响,结果表明聚乙烯醇纤维和水溶性粉末具有不同的增韧机理.
关键词:
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地质聚合物
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聚乙烯醇
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压折比
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增韧
Abstract:
Because of the poor toughness of the slag/fly ash based geopolymers, the polyvinyl alcohol (PVA) fiber and the water-soluble powder are used to modify the geopolymers to improve the toughness. The research shows that the compressive strength and flexural strength increased by 9.6% and 25% respectively. When the content of PVA is 0.5%, which could enhance the toughness. However, the increase of PVA powder content could lead to the decrease of the mechanical properties. With the increase of the content of PVA fiber, the compressive strength decreases continuously, the flexural strength increases and the compressive to flexural ratio decreases. When the content of PVA fiber is 3%, the flexural strength increased by 35%, the compressive to flexural ratio decreased by 35%. The effects of PVA on the microstructure of geopolymers are investigated by XRD and SEM-EDS and the results show that PVA fiber and PVA water-soluble powder have different mechanism.
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