天然纤维/环氧树脂-混凝土的力学性能及老化规律

《复合材料学报》优先在线发表论文。

摘  要：环氧树脂-混凝土是混合树脂、固化剂和砂石骨料等原料固化成型的一种复合材料，因其优异的性能，已成为土木与建筑应用中富有潜力的新型工程材料。本文将高性能的天然纤维（剑麻和苎麻）引入环氧树脂-混凝土，以进一步增强其力学性能。实验结果表明，极少含量的天然纤维便能够提升环氧树脂-混凝土的抗弯拉强度，占材料总体积的体积分数为0.36 vol%的剑麻纤维和苎麻纤维可以将混凝土的抗弯拉强度分别提高10.5%和8.4%。天然纤维对环氧树脂-混凝土抗弯拉强度的增强效应可以用基于混合率的并联模型描述，模型预测结果与实测结果相比，相对误差低于5.1%。利用紫外光耐气候试验箱模拟华南地区自然环境的日照辐射和湿热条件，研究了天然纤维/环氧树脂-混凝土抗弯拉性能随老化时间的衰减。当等效老化时间为6年时，天然纤维/环氧树脂-混凝土的抗弯拉强度分别下降了14.3%（剑麻纤维）和15.9%（苎麻纤维）。实验观察到的衰减规律可采用复合材料湿热老化的剩余强度模型描述。

关键词：环氧树脂-混凝土；天然纤维；抗弯拉强度；混合率；老化；剩余强度模型

Abstract: Epoxy polymer concrete is a kind of composite material prepared by mixing epoxy resin, curing agent and aggregate. It has become a type of novel engineering material with great potential in civil and architectural applications, due to its excellent performance. In this paper, high performance natural fibers (sisal and ramie) were incorporated into epoxy polymer concrete to further enhance their mechanical properties. The experimental study shows that the flexural strength of epoxy polymer concrete can be improved with natural fibers at very low loadings.0.36 vol% natural fibers lead to the increases in flexural strength by 10.5% (ramie fibers) or 8.4% (sisal fibers). The reinforcing effects of natural fibers on the flexural performance of epoxy polymer concrete can be well described by the parallel model based on the rule of mixture. The theoretical prediction achieves a good agreement with the measured values, with small relative deviation up to 5.1%. The ultraviolet radiation and hygrothermal conditions of natural environment in south China were simulated using a UV accelerated weathering chamber, to the flexural performance decay of natural fiber/epoxy polymer concrete during aging. After the aging of 6 years (equivalent aging time), the flexural strength of natural fiber/epoxy polymer concrete decreases by 14.3% (sisal fiber) and 15.9% (ramie fiber). The attenuation rule can be described using the residual strength model of fiber reinforced polymer composites in hygrothermal environment.

Keywords: epoxy polymer concrete; natural fibers; flexural strength; rule of mixture; aging; residual strength model

作者：潘志伟等，华南理工大学 土木与交通学院，广州

通讯作者：潘志伟等，华南理工大学 土木与交通学院，广州

全文详见中国知网学术期刊优先数字出版。