Synchrotron X-ray micro-tomography investigation of the early hydration of blended cements: A case study on CaCl2-accelerated slag-based blended cements

In situ X-ray Micro-Tomography (XMT) analyses with a pixel size of 0.325 µm were conducted on slag-based blended cements containing 75% Ground-Granulated Blast-Furnace Slags (GGBS) and 25% Ordinary Portland Cement (OPC), or without CaCl2 acceleration. Results show the identification main cementitious phases need to perform data repeatability tests in order allow their quantification. Investigation early hydration during first 31 h by image subtraction showed (i) dissolution OPC/GGBS, (ii) precipitation hydrates including C-S-H, (iii) accelerating effect CaCl2, (iv) phase-identification based specific grey level.