Spatial Gradient Analysis of Single-Particle Hydration and Inter-Particle Interactions in Cement–Fly Ash–Slag System Using BSE-EDS Images
Year: 2026
Type: article
Abstract: Ion diffusion, the precipitation of hydration products, and interactions between different reactive particles are critical for optimizing the design of low-carbon cementitious systems. However, at the sub-micron scale, the complex spatial and chemical interactions among diverse components at an early age remain challenging to quantify. In this study, a machine learning-assisted BSE-EDS analytical method was applied to quantify both the phase assemblage and the spatial element features of cement-fly ash-slag ternary systems. The equidistant strip delineation of single-particle and rectangular inter-particle path methods were employed to quantify ionic diffusion gradients in the ternary systems. Single-particle strip analysis quantified the hydration front of clinker, slag and fly ash, while inter-particle analysis identified a persistent calcium-starvation zone at slag-fly ash interfaces. This region is characterized by exceptionally high Si/Ca ratios and a lower average atomic number and material density due to ionic diffusion limitations. These findings identify the slag-fly ash interface as the primary microstructural weak link, providing a robust methodology for capturing the chemical heterogeneities and optimizing the design of sustainable cementitious materials.
Source: Materials
DOI: 10.3390/ma19102161
Authors: Lixuan Mao, Zheyuan Cao, Lihui Li, Bin Zhang, Fuqiang He
Language: English
Subfield: Civil and Structural Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W7161947294