Carbon Sequestration Strategies in Cement Based Material: Carbon Nano Platelet Admixture Interaction and Long term Carbonation of CO2 Injected Concrete Blocks

Two novel approaches to sequester carbon in concrete were examined in this study. First, carbon nano platelets exposed to CO2-laden flue gas were explored for possible use as a concrete additive to improve mechanical properties. However, carbon nano platelets also have the potential to interfere with the performance of air entraining admixtures (AEAs) in concrete. The capacity for carbon to adsorb AEAs is already widely recognized in terms of unburnt carbon residues present in coal combustion fly ash. In this research, adjustments to Vinsol resin and synthetic AEA dosages necessary to maintain adequate air void parameters in mortars were determined using a combined adsorption isotherm test based on chemical oxygen demand (COD). Second, the long-term carbonation of industrially produced concrete blocks manufactured using early-age CO2 injection was explored using an accelerated carbonation chamber. Carbonation rates were found to be similar for CO2-injected and non CO2-injected blocks.M.A.S