Work

The influence of low temperature rise polymer on early cement hydration from the point of view of hydration kinetics and thermodynamics

Year: 2024

Type: article

Abstract: The key to studying the influence mechanism of additives on the cement hydration process lies in revealing the influence process of admixtures on the evolution of chemical driving forces of relevant phases in the cement hydration process. This study is the first to adopt the Krstulovic-Dabic (K-D) kinetic model to investigate the hydration mechanism and kinetic parameters of a cement system with a low-temperature polymer (CAMC). Gibbs Energy Minimization Selektor (GEMS) was used for pore solution composition analysis of cementitious system and calculation of saturation index. The results show that the exponent and reaction rate constant of the (K-D) model decrease with the increase of hydration age and CAMC content, with K1 significantly greater than K2 and K3 being the smallest. The saturation index of calcium hydroxide (CH) and ettringite (AFt) is greater than 0, indicating that both phases are supersaturated in all samples. The transition time from supersaturation to undersaturation of gypsum is delayed, confirming the delayed consumption of gypsum by CAMC. This provides new insights into the effects of admixtures on cement hydration and the mechanisms of cement hydration.

Source: Case Studies in Construction Materials

DOI: 10.1016/j.cscm.2024.e03466