232 / 2022-06-14 15:21:53

Impact behavior of waste polyethylene terephthalate fiber reinforced concrete with recycled aggregate

Polyethylene terephthalate (PET) fiber; recycled aggregate concrete; Dynamic compressive behavior

As one of green fiber materials, polyethylene terephthalate (PET) fibers are mainly produced from recycled plastic bottles. The composite material with PET fibers as reinforcement has a large tensile rupture strain of more than 5% and exhibits a bilinear stress-strain relationship. Meanwhile, the urbanization has led to the demolition of many existing reinforced concrete (RC) structures. The disposal of the waste concrete is posing threat to our environment. Crushing waste concrete, recycling the coarse aggregate and forming recycled aggregate concrete (RAC) will not only address environmental problems, but also save resources for new construction. Adding PET fibers into RAC can potentially mitigate damage and increase ductility. This study presents an experimental investigation on the effect of recycled coarse aggregate (RCA) replacement ratios, and fiber volume ratios on the dynamic compressive behaviors of PET fiber reinforced concrete under various strain rates. A split Hopkinson Pressure Bar (SHPB) device was used to carry out this study. The experimental results showed that the PET reinforced recycled aggregate concrete is a strain rate sensitive material. The compressive strength, critical strain and toughness increased with the growth of the strain rate. The addition of the RCAs increased the porosity of the specimen, which resulting in a reduction in the dynamic compressive strength and an increase in the critical strain. The inclusion of PET fibers into a concrete matrix improved the critical strain and substantially reduced the damage, owing to the bridging and cracking resistance of PET fibers. Nevertheless, the existence of fibers also enhanced the defects of the concrete, which decreased the dynamic compressive strength.



Keywords: Polyethylene terephthalate (PET) fiber; recycled aggregate concrete; Dynamic compressive behavior