Exploring the reinforcing mechanism of graphene oxide in cementitious materials through microstructural analysis of synthesised calcium silicate hydrate

• Published in: Cement & concrete composites Vol. 153; p. 105717
• Main Authors: Nithurshan, Mylvaganam, Elakneswaran, Yogarajah, Yoda, Yuya, Yano, Keiichi, Kitagaki, Ryoma, Hiroyoshi, Naoki
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2024
• Subjects: Calcium silicate hydrate (CSH); Graphene oxide (GO); Microstructure; Reinforcing mechanism; Calcium silicate hydrate (CSH); Reinforcing mechanism; Graphene oxide (GO); Microstructure
• ISSN: 0958-9465
• DOI: 10.1016/j.cemconcomp.2024.105717

Graphene oxide (GO) has been shown to enhance the mechanical properties and durability of cementitious materials, although the exact reinforcement mechanism is not fully understood. Given the critical role of calcium silicate hydrate (CSH) in determining these materials' properties, this study investigates the microstructural changes in CSH with the incorporation of GO. Using a co-precipitation method, CSH samples with and without GO were synthesised and characterised through thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and nuclear magnetic resonance (29Si NMR and 1H NMR). The results demonstrated that GO incorporation enhances the polymerisation and crystallinity of CSH, as evidenced by TGA and XRD. FTIR and SEM analyses indicated that the CSH structures became more ordered and denser with GO addition. NMR analysis further confirmed improved structural order and reduced interlayer spacing. Overall, incorporating GO into CSH significantly increases crystallite size and promotes a more ordered CSH structure. These effects collectively result in enhanced load transfer, improved crystal interlocking, and a synergistic improvement in the mechanical properties and durability of cementitious materials.