Material Design of Cement for Increased Waste Usage and Reduction of CO₂ Emissions

Abstract

Japan’s cement industry contributes to the recycling of resources by using various industrial wastes and by-products. Given the low probability of growth in demand for cement over the long term, it is necessary to increase the amount of waste consumption to secure a specified volume of processed waste. Furthermore, the industry must facilitate efforts to prevent global warming. Therefore, the comprehensive material design of cement, in consideration of both environmental impacts and properties, is expected to become increasingly important. For this study, the influences of mineral composition and admixture content of cement on demand characteristics—waste usage, CO₂ emission, and strength development—were estimated using a method combining blending calculations and the phase composition model. These estimations underscored the need for the future cement to have greater use of waste by increasing the interstitial phase content in clinker prior to the use of admixture. Estimation results also showed the possibility of producing cement having practical strength development, more waste usage, and less CO₂ emissions than current ordinary Portland cement.