Preparation of Regular Cement Hydration Crystals and Ordered Microstructures by Doping GON and an Investigation into Its Compressive and Flexural Strengths

Abstract

Abstract:In this work, we found that by controlling the size of the graphene oxide nanosheets (GON) at 5-140 nm, 5-260 nm and 5-410 nm, respectively, we could prepare regular shaped cement hydration crystals with the shape of nano-needle-like, flower-like, and polyhedron-like crystals, respectively. Together, these crystals formed an ordered structure of cement composites on both the micro and macro levels, and the compressive and flexural strengths of the cement composites obviously increased when compared to the control samples. Our results indicated that the smallest structural unit of regular crystals was the nano-polyhedron-like crystals, which consisted of AFt, AFm, CH, and crystallization C-S-H, and could assemble into regular needle-like crystals, flower-like crystals, and polyhedron-like crystals, as well as an ordered structure on the micro and macro levels. Most of the C-S-H was transferred into a monoclinic system crystals and the remainder played the role of an adhesive in the forming process of regular crystals and structure. The cracks and holes in the cement composites disappeared by the self-repairing effect of the growing hydration crystal. The results indicate that ordered structural cement composites with defect-free structures and high strength can be prepared using GON with a suitable size range.

A holistic review of cement composites reinforced with graphene oxide

“…Cui et al [78] further disagreed with Lv et al [5]that the crystalline or petal-shaped substances were not part of hydration products, but just calcium carbonate due to the carbonation reaction when preparing the sample of cement composites. The understanding of the formation mechanism and shapes of hydration products were further explored by Lv et al [44,57] focusing on controlling the shapes of hydration products by doping GO nanosheets. The formation mechanism of cement hydration products involving GO is illustrated in Fig.8.…”

“…For example, Lu Z. and Li Z have co-authored in multiple publications[42,[54][55][56]. Lv S. has been leading the research within the cluster in multiple research outputs[4][5][6]15,41,[44][45][57][58][59]. Quantitative measurements provided in…”

Effect of Graphene Oxide/Graphene Hybrid on Mechanical Properties of Cement Mortar and Mechanism Investigation

“…In comparison to control specimen, FTIR was used to determine the functional groups. The results of FTIR spectra presented in Figure 3c indicate that in comparison to GR, GO carried more functional groups, including carboxyl groups (-COOH, 3200, 1582 cm −1 ), carbonyl groups (C=O, 1720 cm −1 ), hydroxyl groups (-OH, 1416 cm −1 ), and ether bonds (-C-O-C-, 1260, 1110 cm −1 ) [29][30][31]. The existence of large amounts of functional groups in GO resulted in excellent hydrophilicity, improved stability in aqueous solutions, and showed potential as dispersant for other nano-materials.…”

Creep behavior of graphene oxide reinforced cement composites: Experiments, numerical simulations, and prediction models

“…10 As a derivative of graphene, GO can modify the microstructure of cement composites at the nanoscale, [11][12][13][14][15] developing the microstructure of hydrate products from needle-like rods to ordered structures, such as flower-shaped and lamellar, promoting the growth of hydrate products, filling pores, and regulating hydrate products to achieve property control in cement composites. [16][17][18] However, to the best of our knowledge, the enhancement of GO in the creep behavior of cement composites has not been studied.…”