STUDY ON IMPROVEMENT OF INITIAL HYDRATION OF CEMENT AND NUCLEATION EFFECT BY USIBG WASTE CONCRETE POWDER

• Published in: Cement Science and Concrete Technology Vol. 78; no. 1; pp. 70 - 78
• Main Authors: FUJIMAKI, Tatsuya, SAITO, Tsuyosi, KAMIMURA, Koya, HOSOKAWA, Yoshifumi
• Format: Journal Article
• Language: English; Japanese
• Published: Japan Cement Association 31.03.2025
• Subjects: C-S-H; Conduction calorimeter; Fractal; Nucleation seeding; Waste concrete powder; Water vapor adsorption; α-C2SH
• ISSN: 0916-3182; 2187-3313
• DOI: 10.14250/cement.78.70

In this study, the hydration promoting effect of α-C2SH prepared from waste concrete powder was examined in terms of the reaction rate of C3S and heat of hydration. In addition, the fractal dimension, a measure of the complexity of the hardened cement paste surface, was calculated for the prepared samples and analyzed in relation to the hydration promotion effect as a measure of the complexity of the C-S-H generated by the hydration of C3S on the particle surface. The results showed that the addition of α-C2SH prepared from waste concrete fines shortened the induction and acceleration phases in the early stages of hydration. In addition, regardless of the specific surface area and average particle size of the additive, the surface fractal dimension Ds in the initial stage of hydration increased rapidly, especially for the additive that showed an accelerating effect on hydration.