Z.Y. Lu, Z.J. Li, H.Y. Ma
The Hong Kong University of Science and Technology, Hong Kong
pp. 197 - 200
Keywords: graphene oxide, cementitious materials, mechanical behavior, thermal behavior
With the rapid development of the infrastructure, Portland cement has widely been used for building and construction. High performance cement and concrete is urgently needed to satisfy the high-rise buildings, marine tunnel and cross-sea bridges. However, several limitations of cementitious materials still need to be resolved. Firstly, although the compressive strength of cementitious composites can be significantly improved to a high level, the brittleness and lack of flexural/tensile strength are hardly to be satisfied. Secondly, a common method to improve the tensile strength and toughness of the cementitious composite is by adding fibers, such as polyvinyl alcohol (PVA) fibers, steel fibers and carbon fibers. In particular, Strain Hardening Cementitious Composites (SHCCs) can be obtained when PVA fibers are incorporated into cementitious materials. However, how to improve the bonding between the fiber and cement matrix in SHCCs is still under investigation. Moreover, in terms of the building energy conservation, phase change materials (PCMs) for latent heat thermal energy storage (LHTES) in buildings has been widely studied due to the advantages of high heat energy storage and constant temperature during phase change process. However, the leakage problem after melting and the lower thermal conductivity of PCMs are the two main drawbacks limiting wide application. Therefore, it is very important and urgent to develop an improved method, not only encapsulating the PCMs composites, but also improving the thermal conductivity of the PCMs composites. Graphene oxide (GO) is a two-dimensional single layer material with sp2-bonded carbon atoms, decorated by a large number of covalent oxygen-containing groups-hydroxyl, carbonyl and carboxyl. The exceptional mechanical and thermal properties of GO make it a good candidate for a wide range of applications, such as polymer composite materials, energy storage, biomedical applications and catalysis. In this paper, three perspective applications of GO in the cementitious materials are discussed. Firstly, the mechanical behavior of the GO reinforced cement paste is investigated. In addition, the improved bonding between the fiber and cement matrix by GO incorporation is studied. Finally, the effect of GO on leakage-bearing and thermal conductivity of PCMs composites for building and construction is discussed. In conclusion, GO has a great potential in building applications in the future.