Synergistic Effects of CO2 Curing and Recovered Carbon Black Nano additives on Early Age Performance of Cementitious Composites

Both CO2 curing, a potential precast plant treatment, and nano-additives can enhance the strength and reduce the porosity of cementitious composites. However, their simultaneous application may lead to interactions that influence curing effectiveness, particularly as nanoparticles may alter the effectiveness of CO2 curing. This study investigates the combined effects of CO₂ curing and nanomodification on the early-age strengths of precast cementitious composites, given its importance for precast industry productivity. Mortar and paste batches incorporating recovered carbon black (rCB), a nanomaterial derived from recycled waste rubber, were prepared with 0% and 2% rCB by cement weight. Specimens form each mixture were subjected to both normal curing and CO2 curing. Compressive strength of mortars and thermogravimetric analysis of cement paste were performed at 7 days. The results indicate that rCB additive can enhance the early-age strength of CO2-cured cementitious composites, presenting a potential opportunity for waste valorization of a recovered nanomaterial.