基于多指标下POM纤维对EPS轻型混凝土性能的影响

Effect of POM fiber on multi-performance of EPS lightweight concrete

为探究聚甲醛(POM)纤维对聚苯乙烯(EPS)轻型混凝土性能的综合影响,避免以往单纯依赖力学性能指标评价的不足,比选后基于长度为12 mm的POM纤维研究了不同性能评价指标下POM纤维的最优掺量。结果表明:基于基本的力学性能及相对动弹性模量变化绝对值,掺量为0.9%时,POM纤维对EPS轻型混凝土的增强效果最优,冻融损伤最低;基于吸水性及流变性能指标,掺量同样为0.9%时浆体稠度及抗吸水能力最佳;基于干缩性能,则掺量为1.2%时,浆体抗干缩效果最优;基于冻融后相对弹性模量变化率,则掺量为0.6%时相对弹性模量衰减率最低;研究揭示了POM纤维增强EPS轻型混凝土的复杂性和多样性,进一步通过微观分析,辅证了POM纤维增强增韧EPS轻型混凝土的机理。

In order to explore the comprehensive influence of polyoxymethylene(POM)fiber on the performance of polystyrene(EPS)lightweight concrete and avoid the shortcomings of the evaluation solely relying on the mechanical properties index,the optimal dosage of POM fiber under different performance evaluation indexes was studied based on the POM fiber with a length of 12 mm.The results show that,based on the basic mechanical properties and the absolute change of relative dynamic elastic modulus,POM fiber has the best strengthening effect on EPS lightweight concrete and the lowest freeze-thaw damage when the dosage is 0.9%.Based on the indexes of water absorption and rheology,the consistency and water absorption resistance of slurry with the same dosage of 0.9%are the best.Based on dry shrinkage performance,when the dosage is 1.2%,the dry shrinkage resistance is the best.Based on the change rate of relative elastic modulus after freeze-thaw,the decay rate of relative elastic modulus is the lowest when the content is 0.6%.The study reveals the complexity and diversity of POM fiber reinforced EPS lightweight concrete,and further proves the mechanism of POM fiber reinforced and toughened EPS lightweight concrete through microscopic analysis.