Abstract
The rheological properties of cement-based materials made with manufactured sand vary with the content and physio-chemical properties of microfines in the sand. However, the evaluation of rheological properties regarding the structural build-up at early-age hydration remains challenging for the cementitious materials prepared with different manufactured sands, due to complicated underlying structuration mechanisms. This paper studies the effect of disparate microfines of different manufactured sands on the non-linear growth of static yield stress of cement pastes at rest. The paste mixtures were prepared with 0.40 and 0.275 water-to-cement mass ratio (W/C) and had a fixed mini-slump flow of 240 ± 5 mm. Test results show that the additional microfines facilitate the rapid early increase of static yield stress over 10 min rest, due to the intensified flocculation between total solid particles and simultaneously the greater strengthening of the agglomerating network by rapid cement hydration. Besides, the microfines promote the exponential growth of static yield stress over 10 to 120 min rest, given the accelerated particle network densification by the continuous cement hydration. Qualitative approaches describing the enhancement of flocculation by rapid early hydrates and the particle network densification during the succeeding early-age hydration are proposed to evaluate the rapid increase and exponential growth of static yield stress, by taking into account the evolving ratio of solid particles to excess interstitial solutions and the degree of cement hydration.
Recommended Citation
J. Zhu et al., "Underlying Mechanisms of the Effect of Microfines of Manufactured Sand on Non-linear Structural Build-up of Cement Paste," Cement and Concrete Research, vol. 190, article no. 107812, Elsevier, Apr 2025.
The definitive version is available at https://doi.org/10.1016/j.cemconres.2025.107812
Department(s)
Civil, Architectural and Environmental Engineering
Keywords and Phrases
Hydration degree; Microfines; Microstructure densification; Particle flocculation; Structural build-up
International Standard Serial Number (ISSN)
0008-8846
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2025 Elsevier, All rights reserved.
Publication Date
01 Apr 2025
Included in
Civil Engineering Commons, Engineering Education Commons, Materials Science and Engineering Commons, Structural Engineering Commons, Transportation Engineering Commons
Comments
Department of Education of Shandong Province, Grant 2023CEM010