An atomistic building block description of C-S-H - Towards a realistic C-S-H model. (May 2018)

• Record Type: Journal Article
• Authors: Kunhi Mohamed, Aslam; Parker, Stephen C.; Bowen, Paul; Galmarini, Sandra
• Is Part Of: Cement and concrete research. Volume 107(2018)
• Page Start: 221
• Page End: 235
• Publication Date: 2018-05
• Subjects: Crystal structure -- Cementitious systems -- Molecular dynamics -- Density functional theory -- C-S-H; Cement -- Periodicals; Cement -- Research -- Periodicals; Concrete -- Periodicals; Concrete -- Research -- Periodicals; Ciment -- Périodiques; Béton -- Périodiques; Cement; Concrete; Periodicals; 620.135
• DOI: 10.1016/j.cemconres.2018.01.007
• Languages: English
• ISSNs: 0008-8846

Abstract

Abstract: Understanding the atomistic structure of Calcium silicate hydrate (C-S-H), the main product of cement hydration, is of paramount importance to better formulate sustainable cement. The existing atomistic models are not in total agreement with experimental results and fail to explain the nanosized nature of C-S-H. Here, we present a new approach for describing the complexity of these structures at the molecular level, enabling a detailed comparison of C-S-H models. The new methodology encodes a full, large scale atomistic C-S-H structure by a simple, readable string of characters, similar to the way the base sequence in DNA encodes a vast range of different proteins. We then use the methodology to assess 14 Å tobermorite-defect structures and their stabilities using DFT and classical molecular dynamics. Finally we highlight how the model may be extended to develop reliable atomistic C-S-H models for a range of Ca/Si ratios and conditions.