Title: Utilization of Waste CO₂ Generated Vaterite in Blended Cements

Author(s): Ying Wang, Jesus Gonzalez, Craig W. Hargis

Publication: Symposium Paper

Volume: 362

Issue:

Appears on pages(s): 854-870

Keywords: cement, early age strength, setting time, sustainability, vaterite

DOI: 10.14359/51742014

Date: 6/17/2024

Abstract:
This paper discusses the results of a 5-10% vaterite replacement of SCMs in certain blended cements. In cement-fly ash blended cement, a 10% vaterite replacement of fly ash achieved a 40% higher strength at 1 day and maintained a consistently higher strength than the cement-fly ash blended cement control through 56 days. A 10% vaterite replacement of slag in a cement-slag blended cement achieved approximately 20% higher strength at 3 days. For a cement-slag-fly ash blended cement, a 10% replacement of fly ash with vaterite achieved a 30% to 50% strength increase through 7 days, and a 50 to 110-minute reduction in the initial setting. The bulk resistivity of all the blended cement was increased after including vaterite, indicating the potential for better durability. The alkali-silica reaction test resulted in low amounts of expansion confirming the vaterite-blended cements’ durability. Hydration analysis using isothermal calorimetry and thermogravimetry also showed extra early-age hydration reactions due to vaterite inclusion. Using vaterite in blended cement can help reduce the embodied carbon and enhance many of the engineering properties, such as setting time, early-age strength, and durability.