Early-age monitoring of cement-microcement compositions

combined evaluation of chemical reaction and viscoelastic changes during the hardening

Abstract

Enhancing cement efficiency in concrete and mortar is crucial for reducing the environmental impact of construction by minimizing binder consumption without compromising performance. This study examines the reaction kinetics and hardening of pastes made with two types of Portland cement, each with distinct particle size distributions and mineralogical characteristics. The chemical contribution to hardening was monitored using isothermal calorimetry, while in-situ X-ray diffraction was used to monitor the formation of hydrated compounds. Physical changes were assessed by oscillatory rheometry, focusing on the elastic storage modulus (G'). The detected proportions of portlandite and ettringite influenced the initial reaction stages but had little effect on heat release. The combined analysis reveals the correlation between physicochemical parameters and microstructural changes, emphasizing their role in agglomeration and flocculation forces that accelerate paste hardening.