Mechanical behaviour of C-S-H agglomerates at multiscale

Calcium-Silicate-Hydrate (C-S-H) is the primary binding phase in cement and plays a crucial role in lifecycle performance of concrete. Understanding its multiscale mechanical properties is essential for optimizing its performance. In this study, we employed atomic force microscopy (AFM), nanoindentation and oedometric test to characterize multi-scale mechanical behaviours of C-S-H with different chemical composition and micro-structure. Moreover, a calculation framework is used to bridge inter-scale gaps. Our results reveal the complex hierarchical features of C-S-H and its impact on mechanical properties including elastic, plastic, and viscous responses. We also identify the critical role of chemical composition including calcium-to-silica ratio and water content on the observed mechanical behaviours. Additionally, our multiscale model provides a valuable tool for rational design of C-S-H-based materials with tailored mechanical properties at less material cost.