Speaker
Description
With the rising requirements of lowering global CO2 emissions, cement production, which accounts for nearly 8% of global CO2 emissions is a key target for reduction. One of a most effective method of reducing emissions is to reduce use. This leads to the encouragement of finding alternative less environmentally damaging cementitious materials to reduce reliance on emission-producing cement. The most effective strategy is to reduce cement consumption by incorporating alternative, low-carbon cementitious materials. While fly ash has been widely used as a supplementary cementitious material (SCM), declining availability necessitates the exploration of viable alternatives. This study investigates the performance of Icelandic Volcanic Pozzolan (VPI) as a partial replacement for ordinary portland cement (OPC), both in binary and ternary blends. Silicon manganese slag (SiMn slag), a byproduct of silico-manganese alloy production, is used as a co-replacement material to further enhance sustainability and resource utilization. Six different mortar combinations were tested, incorporating 50% to 90% total OPC replacement levels. Compressive strength development was studied at 3, 7, 28, and 56 days. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis of the 28-day samples were conducted to study the composition of the microstructure. Isothermal calorimetry was used to compare the heat development changes due to incorporation of SCMs. The results indicate that VPI and SiMn slag show promising potential as partial replacements for OPC, with 50% VPI replacement yielding a notable increase in compressive strength and favorable microstructural characteristics. The results imply that VPI and SiMn combination could serve as a viable and sustainable alternative to conventional cement in certain applications, potentially reducing clinker use and associated CO₂ emissions.
