Optimization of cement quantity through the engineering of particle size distribution – a sustainable approach

Cement is the most used building material on the planet and is responsible for 8% of the total CO2 released. In the coming decades, due to increased population and infrastructure needs, a surge in cement demand is expected. To meet the demand without affecting the carbon foot-print the efficiency of cement needs to be enhanced. This paper presents a novel approach to achieve enhanced efficiency through the engineering of particle size distribution. Since raw materials used in cement production vary in quality across the globe, the only feasible method of enhancement is through modification of mechanical parameters such as particle size and distribution. The paper explains the details of an experimental study on cement and concrete using a “Stimulator” produced by grinding commercially available OPC. Stimulator content was varied between 0 and 100% in the interval of 10%. Various tests such as water requirement, setting times, the heat of hydration, chemical shrinkage and compressive strength parameters were conducted, thus determining the optimum dosage of the stimulator. Despite the reduction in the average particle size of cement by 38–47%, water requirement has shown a nominal rise of 10–17% for S40 to S50 cement mixes, respectively. Concrete Samples with the optimum dosage of stimulator depicted 20–25% lesser requirement of cement to achieve strength equivalent to that of concrete containing OPC only. This reduction in the requirement of cement quantity leads to lower cost and lower amount of CO2 released. Implementation of this method of cement production does not require the introduction of new machinery. Unlike pure OPC, the cement & stimulator mix portrayed a double peak PSD arrangement representing the participation of 2 sets of particles in the cement matrix sizes. Durability tests conducted on concrete samples with the optimum dosage of stimulator and OPC have depicted better durability than concrete samples with OPC only