Effect of calcium acetate on some properties of blended portland cement

Tóm tắt

The objective of this study is to evaluate the influence of calcium acetate (CA) content on certain properties of blended Portland cement. The investigated CA dosages were 0%, 0.3%, 0.6%, and 1.0%. The properties examined include water of consistency, setting time, heat of hydration during the first 24 hours, compressive strength at 1, 3, 7, and 28 days, and soundness. The results indicate that increasing CA content from 0% to 1.0% reduces the water of consistency by approximately 2%. While CA has a negligible effect on the initial setting time, it shortens the final setting time by around 20 minutes. An increase in CA content accelerates the early-stage hydration rate but subsequently leads to a reduction in both the peak temperature and the total heat released within the first 24 hours. CA adversely affects the 1-day compressive strength; however, it slightly enhances strength at 3 and 7 days when used at 0.3% and 0.6% dosages. A significant improvement in 28-day compressive strength is observed, particularly at 0.6% CA, which yields the highest enhancement (an increase of 23.8% compared to the control sample). CA does not significantly impact the soundness of the cement, and all tested samples satisfy the requirements of TCVN 6260:2020. Based on the findings, a CA dosage of 0.6% appears optimal, as it minimizes 1-day strength reduction while providing superior strength development at later ages (3, 7, and 28 days) compared to the 0.3% and 1.0% CA mixtures.