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

Area of Science:

• Materials Science
• Civil Engineering
• Chemical Engineering

Background:

• Accurate simulation of cementitious material hydration requires understanding calcium-silicate-hydrate (C-S-H) layer growth around clinker grains.
• Manual measurement of C-S-H layer thickness is unreliable due to significant variations around individual grains and surrounding conditions.

Purpose of the Study:

• To develop and present a software tool for automated, statistical measurement of C-S-H layer thickness.
• To overcome the limitations of manual measurement in terms of reproducibility and feasibility.

Main Methods:

• Development of a software tool for automated identification of clinker grains.
• Statistical measurement of C-S-H layer thickness with minimal manual intervention for thresholding and parameter setting (e.g., particle size, circularity).
• Application of the tool to specimens up to 28 days of age.

Main Results:

• The software successfully automates the measurement of C-S-H layer thickness.
• A significant increase in C-S-H layer thickness was observed, from 0.45 µm at 1 day to 3.04 µm at 28 days.
• Measurement feasibility was limited in older specimens due to reduced pore space and clinker grain availability.

Conclusions:

• The developed software provides a reliable and reproducible method for quantifying C-S-H layer growth.
• The findings quantify the dynamic growth of C-S-H layers during early cement hydration.
• Further research may be needed to adapt the method for aged cementitious materials.