Enhancing the performance of calcium aluminate cement using Vitamin-C as a multifunctional admixture

Vitamin-C (VC) is a water-soluble vitamin abundantly found in various plants. In this work, VC is explored as a green and multifunctional admixture for enhancing the performance of calcium aluminate cement (CAC). Experimental results demonstrate that VC adsorbs onto cement particle surfaces, thereby prolonging the setting time and enhancing the flowability of CAC paste. Furthermore, the presence of VC∼Al 3 + /Ca 2+ chelates promotes the hydration of CAC for a longer age, leading to an increased amount of hydration products. Consequently, porosity is reduced, and the hardened pastes exhibit a higher elastic modulus, contributing to enhanced compressive strength. More importantly, by adding VC, the autogenous shrinkage of CAC is effectively mitigated. For example, a 0.9 % VC addition can extend the setting time more than three times, increase 28 d compressive strength by 9.6 %, and decrease 28 d autogenous shrinkage by 47.7 %. These findings highlight the multifunctional role of VC as a retarder, plasticizer, strength enhancer, and autogenous shrinkage reducer in CAC systems, offering a green and efficient approach to optimizing CAC performance. • Vitamin-C (VC) can be used as a green and multifunctional admixture for calcium aluminate cement (CAC). • The addition of VC prolonged the setting time, improved flowability, and mitigated autogenous shrinkage of CAC. • CAC samples with VC achieve refined pore structure and enhanced mechanical properties. • Both the eco-efficiency and cost-effectiveness of CAC were promoted by adding VC.