Synergistic Performance of Stone Waste Powder and Red Mud and Polypropylene Fibers in Sustainable Green Concrete Development

Abstract

The construction sector all over the world is feeling the pressure of implementing the use of eco-effective materials that reduce the effects of environmental degradation and depletion of resources. The present paper becomes an exploration of the use of the mining waste, namely stone waste powder (SWP) and bauxite residue (red mud, RM) as a sustainable source in conjunction with polypropylene fiber (PPF) to form high-performance, durable concrete. SWP was used as a partial replacement (10-15 %) as well as RM (510 %) in place of ordinary Portland cement, whereas PPF was added in different doses (0.25-0.75 % by volume of cementitious materials) in order to enhance post-cracking performance. To test compressive, tensile, and flexural strength, toughness index, residual strength factor, water absorption, porosity, acid and sulfate resistance, and microstructural properties were tested in a thorough experimental program (SEM, XRD). The high level of the significant effect of SWP and RM synergy and the fiber reinforcement on performance indices was statistically confirmed with the help of ANOVA and Taguchi optimization. Findings showed that the compressive strength gain, flexural strength gain, and reduction of porosity was 18 %, 27 % and 35 % higher, respectively, with the optimum mix that had 15 % SWP, 10 % RM, and 0.5 % PPF than the control. In addition, PPF and SWP improved ductility and crack resistance, and matrix densification was improved by RM, thus attaining the mechanical efficiency and environmental sustainability. The paper opens a new avenue of creating green reinforcing concrete using waste reduction as a value, which is in line with the international sustainable development agenda and can serve as a viable application to green infrastructure.