Mechanism of Clinker Particle Distribution on Hydration and Crack Resistance of Cement

Abstract

With the rapid development of high-performance portland cement, its crack resistance has become a key concern in construction engineering. Clinker particle size is a critical factor regulating cement hydration behavior and crack resistance, yet its intrinsic mechanism remains to be clarified. This study aimed to reveal this mechanism and provide support for anticracking cement development. Portland cement clinker was classified into coarse and fine powders via preliminary grinding + precise separation. Two cements were prepared by mixing 95% of each clinker with 5% gypsum. Comprehensive tests for clinker and cement were conducted. Results showed clinker particle size induced significant differences. Coarse clinker had lower C 3 S / C 3 A but higher C 2 S than fine clinker. Correspondingly, the coarse cement exhibited lower early hydration activity and early strength but sustained later hydration and higher later strength growth. In crack resistance, the coarse cement outperformed fine cement: smaller 120-d drying shrinkage, longer cracking time, and narrower crack width. Controlling clinker particle size to the coarse range effectively improves cement crack resistance while ensuring later strength, providing technical guidance for low-crack, high-durability portland cement production.