Activation of low-carbon emission cements

Paper ID : 1080-ISCH

Authors

mostafa abbas * haayk elmaide

Abstract

Cement production is responsible for approximately 8% of global CO2 emissions. High-belite cement offers lower emissions and energy consumption compared to traditional Portland cement. However, its slow early strength development hinders widespread adoption. This study explores the role of carbonate salts as sources of Li₂O, SrO, and BaO dopants to enhance early strength development in belite by stabilizing a highly reactive polymorph (α'-C₂S) at room temperature. A reference belite is prepared by burning calcite and quartz in a 2:1 mole ratio for 1.5 hours at 1200°C. Belite polymorphs formed in the presence of Li₂CO₃ with 1% Li₂O (as a fluxing and doping agent) and SrCO₃ and BaCO₃ (with amounts equivalent to 8% SrO and 8% BaO, respectively, as mineralizers) were identified. The thermal behavior of the belite mixes and pure carbonates was recorded at temperatures up to 1300°C. The polymorphs formed were defined using X-ray Rietveld analysis and examined via scanning electron microscopy. It was found that β and γ polymorphs formed equally in the belite doped with strontium, while α' appeared in the presence of barium. The decomposition of Li₂CO₃ to Li₂O was inhibited by strontium and barium carbonates due to the increased partial pressure of CO₂, which stabilized the melt.

Keywords

belite, polymorphism, fluxing agent, carbonates, dopants

Status: Abstract Accepted (Poster Presentation)