Life cycle assessment and thermophysical properties of a fly ash-based geopolymer containing drinking water treatment sludge-

Abstract

Fly ash-based geopolymers have emerged as a sustainable alternative in construction, leveraging industrial by-products to mitigate CO2 emissions. This study investigates the novel incorporation of drinking water treatment sludge (DWTS) into fly ash-based geopolymers at varying proportions (5-40%). The authors' focus is to analyze the thermophysical properties and environmental implications, including a robust life cycle assessment case study conducted within the Moroccan context. The comprehensive analysis encompassed X-ray powder diffraction, apparent porosity, water absorption, scanning electron microscopy, hot disc, compressive strength, and a comparative assessment of fly ash-based geopolymer containing 20% of DWTS (GP-DWTS-20) and ordinary Portland cement (OPC). Notably, the results reveal that DWTS enhances thermal performance, with a remarkable 33% reduction in thermal conductivity observed in geopolymers containing 20% DWTS. This enhancement motivates the potential for innovative fly ash-based geopolymers. Moreover, the study contributes quantifiable evidence of a substantial 48% reduction in global warming potential for DWTS-based geopolymers compared to OPC. These findings underscore the environmental benefits of this alternative while emphasizing avenues for optimization in alkaline solution, curing, and renewable energy integration.