A python tool to determine the thickness of the hydrate layer around clinker grains using SEM-BSE images

TL;DR

This paper introduces a Python software tool that automatically measures the hydrate layer thickness around clinker grains in SEM-BSE images, enabling reliable, reproducible analysis of cement hydration over time.

Contribution

The study presents a novel automated method for measuring C-S-H layer thickness around clinker grains with minimal manual intervention, improving accuracy and efficiency.

Findings

C-S-H layer increases from 0.45 to 3.04 micrometers over 28 days

Automated tool reduces manual measurement errors and effort

Measurement feasibility decreases in older specimens due to pore space limitations

Abstract

To accurately simulate the hydration process of cementitious materials, understanding the growth rate of C-S-H layers around clinker grains is crucial. Nonetheless, the thickness of the hydrate layer shows substantial variation around individual grains, depending on their surrounding. Consequently, it is not feasible to measure hydrate layers manually in a reliable and reproducible manner. To address this challenge, a software has been developed to statistically determine the C-S-H thickness, requiring minimal manual interventions for thresholding and for setting limits like particle size or circularity. This study presents a tool, which automatically identifies suitable clinker grains and and perform statistical measurements of their hydrate layer up to a specimen age of 28 days. The findings reveal a significant increase in the C-S-H layer, starting from 0.45 micrometer after 1 day and reaching 3.04 micrometer after 28 days. However, for older specimens, the measurement of the C-S-H layer was not feasible due to limited pore space and clinker grains.