Hydration Kinetics for Alkaline Activation of Slag from Color Variation Data

• Published in: Molecules (Basel, Switzerland) Vol. 26; no. 12; p. 3764
• Main Authors: Ding, Zhaoyang, Zhou, Jinghai, Su, Qun, Sun, Hong, Zhang, Yichao, Wang, Qing, Bian, Hongguang, Dong, Fengxin
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 21.06.2021; MDPI
• Subjects: alkali-activated slag; average pixel value; Cement; Chemical reactions; Color; color variation; Differential equations; Digitization; Heat; Hydration; hydration kinetics; Image analysis; Image processing; Kinetics; Krstulovic–Dabic kinetic model; Parameters; Reaction kinetics; Slag; Sodium hydroxide; Variation
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules26123764

In this study, we explore a new method based on color variation data to derive the kinetics of the entire process of the hydration of alkali-activated slag (AAS). Using this image analysis technique, we can monitor the induction period that cannot be observed using conventional microcalorimetry techniques. Color variation was recorded across a sequence of 9999 images, which were processed via MATLAB software package. Further, an average pixel value (APV) was determined to represent the color in each image. Reaction parameters, such as color variation velocity v(t), reaction speed ε(t), and hydration degree α(t), that govern the entire hydration process were determined. On the basis of the reaction parameters and a Krstulovic–Dabic kinetic model, integral and differential equations were derived to simulate the three basic processes of AAS hydration. Equations describing the reaction kinetics of AAS with solutions of three different concentrations of NaOH were extracted using this method.