Polyethylene terephthalate (PET) is a new type of fiber‐reinforced polymer (FRP) composite material, which has the characteristics of high performance, high toughness, high tensile fracture load, low elongation, low creep, no rust, and safety in use. The good performance of PET can significantly improve the mechanical properties of its components. A total of six reinforced concrete (RC) beams were produced in the test, one of which was a comparison beam, and the other five were reinforced with PET. In the test, the PET reinforcement spacing, number of reinforcement layers, and laying method were used as control variables, and an experimental study on the normal section bending performance of the specimen was performed. The test analyses the failure characteristics, crack width, bearing capacity, and deflection of the specimens under different reinforcement conditions. The test results showed that PET reinforcement can effectively inhibit the occurrence and development of cracks in RC beams and improve the ultimate bearing capacity and ductility of the components. The smaller the PET reinforcement spacing, the higher the ultimate bearing capacity; the greater the number of PET layers, the better the ductility of the specimen. Additionally, the economy, environmental protection, and portability of PET are of great significance for its application in practical engineering reinforcement.

The objective of this study was to experimentally analyze the effect of size on the eccentric compression performance of damaged square Reinforced concrete (RC) columns reinforced with Carbon Fiber Reinforced Plastic (CFRP) in a bid to improve the rationality of the design of CFRP-reinforced large concrete members. In the experiment, 18 square RC columns with proportional sizes were prepared, and the principle of the proportional changes in the size was strictly controlled. The effects of the size, eccentricity, pre-damage, and number of CFRP layers were considered in the experiment, and the bearing capacity, lateral deflection, rebar strain, CFRP strain, and failure modes of RC columns of different sizes before and after the reinforcement were studied. The experimental results showed that the CFRP reinforcement could improve the bearing capacity and deformability of damaged square RC columns under small eccentric compression; however, the reinforcement effect gradually decreased with increasing size. When the cross-sectional dimensions were 100, 200, and 300 mm, the bearing capacity increased by 26.17%, 17.27%, and 12.98%, respectively, and the ductility coefficient increased by 104%, 44.80%, and 35.20%, respectively.