Large SEM-BSE images of hydrated alite of ages from 1 day up to 1 year

This dataset contains 8-Bit SEM-BSE images of commercially available tricalcium silicate (C₃S; alite, MIII polymorph; Vustah, Czech Republic). The alite was mixed with a water/binder ratio of 0.5. The paste was the cast in small sealed containers, which were submersed with water. The specimens were stored at 22 ± 2°C.

After the desired hydration times (1, 7, 14, 28, 84, 365 days) the hydration was stopped by immersing the prisms in isopropanol and drying them at 60°C for 12 hours. The dried prisms were then embedded in low viscosity epoxy resin and mechanically polished using diamond paste with a grain size down to 0.25 µm. Finally, the specimens were coatet with a thin layer of carbon to avoid charging.

The images were acquired at 10 kV (7 days, smaller image), 12 kV (7 - 365 days) and 15 kV (1 days) using a CBS (concentric backscatter, 14-365 days) and a ABS (1 and 7 days) detector within a Thermofischer Helios G4 UX.

Table 1: Basic information like resolution, size and phase composition of the images.

The proportions of pores, hydrates and unhydrated clinker shown in Table 1 are the result of manual thresholding of denoised versions of these images and may therefore differ to own measurements.

The scaling is backed into the file and can be read using ImageJ/Fiji.

The unstitched files are provded as 7z archives. The sub-images were arranged in a 10 x 10 grid, with the exception of the 7 days image, which was arranged in a 9x9 grid. The pixel scaling of these files is the same as in the larger files. The unstitched files for the 1 day specimen can be provided on request.

Internal note

These files are included in the following MAPS datasets:

• 2019_04_15 FK C3S 1d
• 2019_04_23 C3S 7d 15 BIB
• 2023_05_24 C32-C2S 14-84 d
• 2023_06_08 C2S-C3S 28d-1year
• 2023_07_18 C3S 7d, C2S 1d, 7d, 3C3S-1C2S 7d

Changelog

• 2023-08-03, V1.1 Added new dataset (C3S 7d_2.tif).
• 2024-02-07, V1.1 modified description (error in hydrate/C₃S measurement for the 14 days dataset)