废PET塑料纤维对再生混凝土基本性能的影响

Effect of Waste PET Plastic Fiber on Basic Properties of Recycled Aggregate Concrete

为了提高再生混凝土(RAC)的力学性能,将废聚对苯二甲酸乙二酯(PET)塑料瓶剪成纤维条制成纤维再生混凝土(FRRAC)。通过纤维再生混凝土与再生混凝土的坍落度试验和强度试验,研究废PET塑料纤维长度、掺量对再生混凝土基本性能的影响,并进行强度影响因素的显著性分析和混凝土微观结构分析。结果表明:与不掺纤维的再生混凝土相比,纤维再生混凝土的流动性降低,且随废PET塑料纤维掺量、长度的增大而下降;掺PET纤维后,再生混凝土的抗压强度总体上有所提高,劈裂抗拉强度明显大幅提高。对于抗压强度,废PET塑料纤维的掺量影响显著;对于劈裂抗拉强度,纤维掺量、长度及二者交互作用均影响显著。掺PET纤维虽然会引入薄弱的界面过渡区,但适量时可使再生混凝土结构致密。

In order to improve the mechanical properties of recycled aggregate concrete(RAC), waste polyethylene terephthalate(PET) plastic bottles were shredded into fiber strip to prepare fiber reinforced recycled aggregate concrete(FRRAC). A series tests like slump test and strength test on FRRAC, together with RAC as reference, were performed to investigate the effects of length and content of waste PET plastic fibers on FRRAC properties. Furthermore, the significance analysis of strength influencing factors and microstructure analysis of concrete were conducted. The results show that, compared with RAC, there is a reduction in the fludity of FRRAC with the increase in length and content of waste PET plastic fibers. The compressive strength overall increases, and the splitting tensile strength significantly increases with the addition of PET fibers in RAC. The content of fibers shows significant effect on compressive strength. As for splitting tensile strength, significant effects of length and content as well as their interaction are all exhibited. Although the incorporation of PET fibers into RAC leads to weak interface transition zones, the microstructure of FRRAC is denser than RAC.