Mechanical Properties and Environmental Impact Assessment of Eco-Friendly Pervious Pavement Blocks Containing High-Volume Fly Ash

Cement production leads to large amounts of carbon dioxide emissions related to global warming. Fly ash, an abundant industrial solid waste that is often used in some Asian countries like Japan, China, Thailand, and Indonesia, was utilized in this study as a replacement of cement to reduce cement consumption in the production of pervious pavement blocks. This study aims to experimentally investigate the potential use of high-volume fly ash on the characteristics of pervious pavement blocks including compressive strength, flexural strength, void ratio, and infiltration rate. Two types of mixture were considered in this experiment. The type A mixtures were designed to have a ratio of cement + binder: coarse aggregate: fine aggregate of 1:2:1 and a water to binder ratio = 0.3. Type B mixtures were produced with a cement + binder: coarse aggregate of 1:3 with the same water-to-binder ratio as Type A. In this type, no fine aggregate was considered. The binder involves the combination of cement and fly ash with a percentage replacement of 40%, 50%, 60%, and 70% by wt. of cement. In addition, the environmental impact assessment was also calculated to examine the CO₂ emission intensity of each material based on the Japan Society of Civil Engineers, Ministry of Health, Labor, and Welfare standard. The results show a promising improvement in the properties of pervious pavement blocks when using high-volume fly ash as a cement replacement. The reduction of CO₂ emissions can also be confirmed, making this product one solution in the construction sector to support practical pathways toward carbon neutrality in Asian countries.