Prosopis juliflora ash – Novel discussion as replacement to cement in the production of sustainable concrete

Construction industries contribute significantly to CO₂ emissions through cement use, while invasive species such as Prosopis juliflora also cause ecological imbalance. This study investigates the use of Prosopis juliflora ash (PJFA) as a partial cement substitute in concrete. The fresh property evaluation revealed a reduction in workability with increasing PJFA content due to its finer particle size and water-holding capacity. Mechanical performance tests showed improvements in compressive, tensile, flexural, elastic modulus, and impact strengths up to an optimal 20% replacement, beyond which reductions were observed. Microstructural analyses including XRD, SEM, FTIR, DTA, TGA, and EDAX confirmed the pozzolanic reactivity of PJFA, with SEM and overlay mapping indicating a densified matrix and enhanced interfacial transition zone at 20% replacement. Life cycle assessment using OpenLCA demonstrated reductions in embodied energy, CO₂ emissions, and water use, highlighting PJFA’s dual role in mitigating the environmental burden of cement production and addressing the ecological challenges of invasive biomass. Overall, the findings establish PJFA as a promising sustainable material for concrete production, with optimal technical and environmental benefits at 20% replacement. In comparison to control concrete, life cycle assessment showed reductions of up to 30% in CO₂ emissions, 28% in embodied energy, and 22% in water use. At the ideal 20% replacement level, compressive strength increased by 6.7%, tensile strength by 5.7%, flexural strength by 7.1%, elastic modulus by 7.1%, and impact resistance by 7.7%.