Nano reinforced cement and concrete composites and new perspective from graphene oxide

As structural materials, cementitious materials are quasi-brittle and susceptible to cracking, and have no functional properties. Nanotechnology is introduced into cementitious materials to address these issues. Nano materials, especially nano carbon materials (NCMs) were found to be able to improve/modify the mechanical property, durability and functional properties of cementitious materials due to their excellent intrinsic properties and composite effects. Here, this review focuses on the recent progress of fabrication, properties, and structural applications of high-performance and multifunctional cementitious composites with NCMs including carbon nanofibers, carbon nanotubes and nano graphite platelets. The improvement/modification mechanisms of these NCMs to composites are also discussed.

Review of nanocarbon-engineered multifunctional cementitious composites

Reactive molecular dynamics and experimental study of graphene-cement composites: Structure, dynamics and reinforcement mechanisms

Incorporating graphene oxide in cement composites: A study of transport properties

Cement based composite materials (CBCM) with superior mechanical strength and excellent durability are always desirable in practical applications. Although considerable research has been reported in the past decades about the use of Nano materials (NMs) for strength and durability enhancement of cement matrix, there is little information available on the use of graphene nano-sheets and their derivatives (GND) in cement-based materials. Particularly the role of GND in hydration processes and their mechanisms of strengthening in cement matrix are unclear. In this paper, a critical review on recent research findings about GND modified cement-based materials was conducted. The review mainly discussed the influence of GND on properties of cement matrix including microstructure, hydration, mechanical properties, etc. The information revealed in this paper would not only provide a comprehensive understanding of the effect of GND on cement composites, but also provide valuable ideas and guidance for similar studies in the future.

A critical review on research progress of graphene/cement based composites

Effect of graphene oxide nanosheets of microstructure and mechanical properties of cement composites

An aqueous dispersion of graphene oxide (GO) nanosheets with different oxygen content was obtained from graphite via oxidation and ultrasonication. The effects of GO nanosheets on the microstructure and mechanical properties of hardened cement paste were determined by scanning electron microscope, X-ray diffractometer and tensile/flexural/compressive strength investigations. The results indicate that GO nanosheets can regulate the formation of flower-like crystals and distinctly improve the tensile, flexural and compressive strengths of the corresponding hardened cement paste: when the oxygen content of GO was 25·45% and its dosage was 0·02% by weight of cement, the tensile strength and flexural strength increased by 197·2% and 184·5% respectively. These results suggest that GO nanosheets can significantly improve the toughness of hardened cement paste. A working mechanism is proposed by which GO may regulate the formation of hydration crystals by a template effect and thus exhibit significantly enhanced ...

Regulation of GO on cement hydration crystals and its toughening effect

Preparation and characterization of polycarboxylate superplasticizers of IPCs (copolymer of itaconic acid and allyl polyoxyethylene ether) and MPCs (copolymer of maleic anhydride and allyl polyoxyethylene ether) are shown. The difference between IPCs and MPCs is that half of the carboxyl groups of IPCs indirectly connect to the main chains through methylene. The effects of the carboxyl group-main chain connection mode on the properties of IPCs and MPCs were investigated by assessing the paste fluidity and the pore diameters and compressive strength. The interaction between IPCs (MPCs) and cement were revealed by zeta-potential and the adsorption amount. The results indicated that the indirect connection mode favorably improved paste fluidity, decreased pore diameters, and increased the compressive strength compared with the direct connection mode. This is likely because that when carboxyl groups are connected to the main chains indirectly, more moving space allows easier adsorption on cement particles. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Chaochao Qiu

Papers

Effect of graphene oxide nanosheets of microstructure and mechanical properties of cement composites

Regulation of GO on cement hydration crystals and its toughening effect

Effects of connection mode between carboxyl groups and main chains on polycarboxylate superplasticizer properties

Preparation method of graphene oxide/amphoteric chitosan intercalation composite for sewage treatment

A weighted adaptive transfer learning for tool tip dynamics prediction of different machine tools