Abstract
This study examines whether cellulose nanocrystals (CNCs) can be used in ordinary portland cement (OPC)-limestone (LS) systems to reduce the carbon footprint of concrete. LS replacement levels between 0 and 30% were evaluated along with CNC dosage rates between 0 and 1% CNC solids per binder volume. Isothermal calorimetry, thermogravimetric analysis, ball-on-three-ball flexural strength, and electrical resistivity tests were used to quantify the performance of the mixtures. The results showed that the addition of CNCs to OPC-LS mixtures resulted in enhanced clinker hydration and up to a 38% increase in the 28-day bulk resistivity. It is demonstrated that a mixture for which 22% of the OPC was replaced with LS and containing 0.2% CNC had an equivalent performance in terms of transport properties compared to the 100% OPC system. This could potentially reduce embodied carbon content by approximately 19.4% when compared to the pure OPC system.