Improve Limestone Utilization

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Researchers at UCLA have improved the utilization of limestone in concrete by developing a system for tailoring the processing parameters to achieve pre-defined mechanical properties and designing processing conditions that enhance the reactivity of the limestone additives. Background Concrete is one of the most widely used and produced materials in the world. However, concrete production adds roughly 5-8% of all CO2 emissions globally. Issues concerning the sustainability of cement have led researchers to investigate other raw materials for concrete, such as limestone. Adding limestone to the mixture changes the mechanical properties of the resultant concrete based on many factors such as the limestone/cement ratio, the limestone particle size, and the rate of hydration. The final mechanical properties must be manually tested after production to understand the effect that the input limestone parameters had on the final product. Furthermore, limestone in concrete mixtures is typically present in conditions that leave it in an unreactive state that limits its versatility. Innovation UCLA researchers from civil engineering, materials science and engineering, and the school of sustainability have developed methods for improving the use of limestone in concrete. A system was developed that marries the final mechanical properties of the concrete to the initial input parameters of the concrete mixture. The amount of limestone content and particle size can be tailored to predict a desired set of mechanical properties without the need for experimental testing. In addition, concrete processing conditions have been established that increase the reactivity of limestone to create carboaluminates that broaden the range of mechanical properties achievable with limestone additives.