Mechanical properties of eco-friendly cement based composite mortars plastic fiber reinforced partially replaced by natural pozzolan and marble waste

Abstract

This research presents a study on the mechanical properties of mortar specimens reinforced with plastic fibers incorporating natural Moroccan pozzolan and marble waste as partial substitutes for cement. Cement is a widely used material, but its production contributes significantly to CO2 emissions. And reducing the carbon footprint of materials without increasing costs is a critical challenge. Hence, numerous studies have investigated the partial or complete substitution of cement. Moroccan pozzolan, a natural pozzolanic material, offers an alternative to energy-intensive cement production. Marble waste, an industrial byproduct generated during the sawing, shaping, and polishing of marble, poses a significant environmental threat. Likewise, the issue of environmental pollution caused by plastic has received lot of attention, and the ideal solution recommended is recycling. In this sense, twenty-one mixes were synthesized and evaluated to explore the mechanical properties of the fiber-reinforced mortars based on natural pozzolan and marble waste added at different weight percentages (5–5/10–5/5–10/15–0/0–15/7.5–7.5) as a partial replacement for cement and 1% and 2% plastic fibers, based on the mortar volume. The hardened mortar mixtures were tested for compressive strength determined after 7 and 28 days, and flexural strength by a three point bending machine. The test results revealed that the mortar specimens containing marble waste and natural pozzolan exhibited the highest compressive strength. The addition of plastic fibers positively influenced the compressive and flexural strength of the mortars. Optimal percentages of natural pozzolan, marble waste, and plastic fibers were identified. The best-performing mixture achieved a compressive strength of 18.67 MPa with 5% pozzolan, 5% marble waste, and 2% plastic fibers added to the mortar mix. This approach not only addresses the uncontrolled disposal of plastic and marble waste but also provides an opportunity to utilize abandoned natural resources, creating more durable and environmentally friendly composite mortars.