Mechanical performance and feasibility analysis of green concrete prepared with local natural zeolite and waste PET plastic fibers as cement replacements

Abstract

Green concrete is a sustainable composite material having natural and waste materials replacing carbon dioxide gas-producing cement, and aggregates in the concrete. Thus, it significantly contributes in reducing greenhouse gas emissions and improves the economic viability of a country as well. Literature suggests that research on the development of green concrete is evolving with widely-available natural and waste materials. Considering the need for the development of green concrete, the current research is conducted. It was hypothesized that the mechanical performance of green concrete prepared by substituting cement with Natural Zeolite (NZ) and waste Polyethylene Terephthalate (PET) fibers will yield stronger, cost-effective, and environmentally green concrete for the construction industry. The microstructure, morphology, and surface properties of the locally extracted NZ were characterized using X-ray Diffraction, SEM and BET, respectively. The influence of quantity, shape, orientations, and surface of NZ and PET fibers along with varying curing times, i.e., 28, 90, and 180 days were considered for experimentation. The main findings of this study are that two optimum proportions for the concrete mixtures are obtained: the first one was 10 % NZ while the other one was 2.5 % PET, and 15 % NZ, and 1.0 % PET. These optimum mixing ratios were found to enhance the compressive strength of concrete, reduce the production cost, and reuse waste PET bottles effectively, which are key points of this study. Furthermore, the workability of the fresh concrete was improved with higher proportions of PET rather than NZ. Finally, the findings of the current research highlight a pragmatic remedial solution for saving energy, turning non-decomposable waste into useful materials for green concrete, and simultaneously contributing to a cleaner environment.