Experimental Investigation of Waste Ceramic Powder and Waste Paper Pulp Ash as a Partial Replacement of Cement in C-25 Concrete

Abstract

Concrete is a significant contributor to environmental issues, with cement production being a major culprit, leading to costly processes, environmental harm, and the depletion of natural resources. To address these concerns, the utilization of waste goods and industrial by-products as alternatives to traditional concrete materials has emerged as a promising solution. This study aims to investigate the mechanical, durability, and micro-structural effects of partially replacing cement with waste ceramic powder and waste paper pulp ash in the manufacturing of C-25 concrete. The experimental analysis includes replacing cement with 10%,20% and 30% of waste ceramic powder (WCP) and 5%, 10% of waste paper pulp ash (WPPA). Results obtained after 7 and 28 days revealed that partial replacement of cement did not notably affect workability; however, it led to enhancements in compressive strength, flexural strength, and acid resistance compared to the control mix. Specifically, Notably, a concrete mix containing 5% WCP and 10% WPPA, as well as a mix with 20% WCP and 5% WPPA, exhibited significant enhancements in compressive strength (5.86% and 1.36% improvement, respectively) and flexural strength (9.96% and 2.07% improvement, respectively) over the control mix, thereby indicating cost reductions. Water absorption and a 2% sulfuric acid solution were used for the sulfate attack test to check the durability property test. The results of the water absorption test are negative; however, the sulfate attack resistance test indicates that the concrete is more resistant to sulfate attack when waste paper pulp ash and waste ceramic powder are mixed. The SEM study also observed distinct changes in the micro-structure of the modified concrete, displaying a more compact composition with reduced pore size and distribution compared to the C25 concrete control. These findings highlight the potential benefits of incorporating blends of WCP and WPPA materials in concrete production, as supplementary cementitious materials to enhance the properties of concrete while reducing environmental impact and costs in the construction industry.