A new hydration kinetics model of composite cementitious materials, Part 2: Physical effect of SCMs

Abstract

This paper is the second part of an overall research project that aims to model the hydration kinetics of composite cementitious materials. The new hydration kinetic model of Portland cement was constructed in the first part of this research project. The aim of this part is to characterize the physical effect of SCMs by modifying some kinetic parameters of the hydration kinetic model of cement. In this paper, the filler effect of SCMs is attributed to the “dilution effect”, “nucleation effect” and “accelerated dissolution effect”. The dilution effect is considered by introducing the actual water/cement ratio into the kinetic model. The nucleation surface area, nucleation and growth rates are modified to account for the nucleation effect and accelerated dissolution effect of fillers. The simulative fit results show that the extra contribution of SCMs due to their filler effect on hydration of cement at early ages has an upper limit: at most 20% extra nucleation surface area, 30% extra nucleation ratio and 40% extra growth ratio of calcium silicate hydrate (CSH). The new modified kinetic model and the value‐taking method of the newly introduced parameters are verified by simulative fitting to the kinetic data from reference. The apparent activation energies of the nucleation rate, growth rate, and diffusion rate are approximately 35 kJ/mol, 36 kJ/mol and 38.5 kJ/mol, which are slightly smaller than those of the pure Portland cement reported in the first part of this research project.

New synthetic glass-based supplementary cementitious materials derived from basalt composition

“…The filler effect of SCMs is a combination of three effects described as dilution, nucleation and accelerated hydration. The influence of SCMs on accelerating the early hydration of cement is well described elsewhere [44].…”

Preparation of Nano Calcite by the Carbon Capture Technology to Improve the Performance of Ultrahigh-Performance Concrete Containing Calcined Clay

“…This difference is attributed to the physical action (filling effect) produced by the nano-CaCO 3 . Generally, this filling effect is divided into three different mechanisms: dilution, accelerated dissolution, and nucleation. , First, when nano-CaCO 3 is added, the cementitious material content in the UHPC decreases correspondingly, thereby increasing the effective water–cement ratio of the mixture. Second, the particle size of the nano-CaCO 3 is smaller, and the spacing between the cementitious material particles decreases with the presence of the nano-CaCO 3 .…”

Influence of Zinc-Saturated Zeolite on Portland Cement Hydration Kinetics

“…e proposed kinetic model can be applied to Portland cement without additives, while with the addition of saturated zeolite, some modifications of Jander's model should be conducted to ensure the scientific and accurate characterization of the hydration of cement [29,30].…”