Impact Assessment of Plastic Strips on Compressive Strength of Concrete

Abstract

This work attempts to analyze the impact of plastic strips on the compressive strength of concrete. Three sets of concrete mixes, one of conventional concrete (CC) and the other two modified concrete with plastic [polyethylene terephthalate (PET)] strips, viz., horizontally oriented plastic strips (MC-H) and randomly oriented plastic strips (MC-R) were tested. Load and deflection controlled analyses show the PET strips as contributing toward 5%–15% enhancement in compressive strength and a substantial reduction in the standard deviation (60%–65%). Further, modified concrete in comparison with conventional concrete exhibits higher stiffness and the early arrival of peak load with relatively steeper response in the postpeak regime. An analytical model attempting to quantify the role of PET strips in offering confinement is proposed in the study. The model describes the contribution of PET in terms of confinement stress and is used to justify early arrival of peak load. It also closely predicts the inclination of failure plane. This study reveals the positive role of PET strips in controlling heterogeneity in concrete behavior, increasing stiffness, and attaining early peak load.