The compressive strength, reaction kinetics and phases evolution of CO2-cured cement pastes at low temperatures

Abstract

Abstract In this investigation, the phase evolution, reaction kinetics, and compressive strength of CO2-solidified cement paste at different temperature ranges (1–20 °C) were explored. Results indicated that temperature and time of carbon curing have a substantial impact on the carbonation process. When the curing temperature increased, the structure, size, and quantity of calcium carbonate polymorphs, as well as their decomposition temperature alter. Vaterite is easier to form when cured at a temperature of 1 °C. Furthermore, although the carbonation process is separated into two stages, it is primarily regulated kinetically by product layer diffusion with an activation energy of about 51.9 kJ/mol. Temperature influences not only the microstructure and reaction process but also the compressive strength and carbonation products, which follow a particular rule as the temperature changes. This research has significant implications for the enhancement of early strength and construction efficiency of building materials in low-temperature environments.