Use of Polyethylene Terephthalate Fibers for Strengthening of Reinforced Concrete Frame Made of Low-Grade Aggregate

Abstract

This chapter presents an experimental finding on the use of waste materials for strength - ening a reinforced concrete (RC) frame prepared with low-grade materials. Compressive, tensile and flexural strength of concrete specimens made of recycled coarse aggregate (RCA) and natural coarse aggregate (NCA) were evaluated to assess RCA suitability for structural use. Results show that the strength parameter decreases in all cases. In order to extend the application of RCA concrete to structural elements, three RC frames were pre pared and tested under monotonic loading. The joint regions of one of the frame were cast using Polyethylene terephthalate (PET) fiber, i.e., PET fiber-reinforced concrete (PFRC). PET fiber (aspect ratio = 25) of 0.5% by weight of concrete used in the PFRC mix was obtained by hand cutting of post-consumer PET bottles. A reference specimen was also prepared using 100% NCA and subjected to a similar loading condition. The RCA frame resulted in a brittle mode of failure and lower load carrying capacity as compared to the reference specimen. However, the presence of PFRC improved the damage tolerance and load resisting capacity and hence seismic parameters such as stiffness degradation, ductil ity and energy dissipation increased. This indicates that PET fiber is a viable substitute for steel fiber as a low-cost material in improving the seismic performance of frame structures.