Synchrotron X-ray micro-tomography investigation of the early hydration of blended cements: A case study on CaCl2-accelerated slag-based blended cements. (28th February 2022)

• Record Type: Journal Article
• Authors: Poirier, Mathilde; Blotevogel, Simon; Noiriel, Catherine; Bonnin, Anne; Kaknics, Judit; Olbinado, Margie; Steger, Laurent; Patapy, Cédric; Cyr, Martin
• Is Part Of: Construction & building materials. Volume 321(2022)
• Publication Date: 2022-02-28
• Subjects: In situ X-ray computed micro-tomography -- Low-carbon cement -- Early hydration -- Microstructure -- Repeatability -- Image subtraction; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2022.126412
• Languages: English
• ISSNs: 0950-0618

Abstract

Graphical abstract: Highlights: Synchrotron X-Ray Micro-Tomography investigation of blended cements. Data repeatability tests are necessary to allow phase quantifications. A transitional dense phase was identified in the pore space of slag-OPC blends. Image subtraction allows to investigate the early hydration of blended cements. Grey levels of dissolved and precipitated phases were identified. Abstract: 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% of Ground-Granulated Blast-Furnace Slags (GGBS) and 25% of Ordinary Portland Cement (OPC), with or without CaCl2 acceleration. Results show the identification of the main cementitious phases and the need to perform data repeatability tests in order to allow their quantification. Investigation of the early hydration during the first 31 h of hydration by image subtraction showed (i) the dissolution of OPC/GGBS, (ii) the precipitation of hydrates including C-S-H, (iii) the accelerating effect of CaCl2, and (iv) phase-identification based on their specific grey level.