Sustainable Infrastructure Development in Indonesia: A Quantitative Evaluation of CO₂ Emission Reduction from Fly Ash-Cement Substitution in Ready-Mix Concrete

¹ Master Program in Occupational Safety and Health, Faculty of Public Health, Universitas Indonesia
² Department of Quality, Health, Safety, Environment and System, PT Adhi Persada Beton, Jakarta, Indonesia

^* Corresponding author: rizka.lailatul@ui.ac.id

Abstract

The construction industry is a major contributor to global CO₂ emissions, particularly through Portland cement production. In Indonesia, the utilization of fly ash in ready-mix concrete presents a promising approach to sustainable construction. This strategy aligns infrastructure development with environmental objectives by potentially reducing emissions and supporting global climate change mitigation efforts. This study investigates the environmental impact of incorporating fly ash into ready-mix concrete employed for the Yogyakarta-Bawen toll road project, with a specific focus on CO₂ emission reduction. Recognizing the critical role of sustainable construction practices in addressing climate change, this research aims to quantify the environmental benefits of substituting 40% of Portland cement with fly ash in FC 30 MPa ready-mix concrete. A comprehensive analysis revealed an 18% decrease in emissions associated with coarse aggregate and a 55% decrease from cement, despite a marginal increase from fine aggregate. Overall, this method achieved a significant 47% reduction in total CO₂ emissions, demonstrating the effectiveness of fly ash in enhancing the sustainability of construction materials. This substantial reduction underscores the potential of fly ash integration as a key strategy for mitigating the environmental impact of large-scale infrastructure projects.