An Investigation Into the Physical and Mechanical Properties of Cement Paste Reinforced by TiO2–GO Nanocomposite

Document Type : Original Research

Authors
Iran University of Science and Technology
Abstract
Portland cement is a crucial mineral chemical that is globally produced in large quantities. It has been reported that in 2011, approximately 3.6 billion tons of Portland cement were produced, and its demand continues to grow. However, this industry's expansion has resulted in increased environmental risks. Therefore, it is important to conduct research to enhance the sustainability of this product. The utilization of nanomaterials in cement and concrete materials has received significant attention in recent years. Employing nanotechnology to modify cement-based materials can significantly enhance the efficacy of this inorganic binder. Primarily, nanoparticles possess the capability to fill the porosity within the cement structure and exhibit pozzolanic properties that reinforce concrete. Additionally, the high specific surface area of nanomaterials facilitates increased reactivity at the nanoscale, thereby enhancing cement hydration and subsequently improving its mechanical properties.


Despite cement and concrete being known for their strength, they are also inherently brittle, which hinders their mechanical performance. In recent years, various nanomaterials have been utilized to address this weakness due to their high specific surface area and strengthening capability in different matrices, including cement. This study aims to evaluate the impact of incorporating a binary nanocomposite of titanium dioxide nanoparticles and graphene oxide to enhance the mechanical properties of the Portland cement.






For hybridization, electrostatic adsorption mechanism was used to connect TiO2 nanoparticles on graphene sheets and synthesize TiO2GO nanocomposite. In this work, TiO2 powder was processed in nitric acid to accumulate protons in the form of H+ functional group on the surface of nanoparticles and make it positively charged. On the other hand, chemically produced GO suspension has an intrinsic negative charge due to the formation and presence of hydroxyl groups (OH) on its surface. Therefore, the combination of these two charged substances with the opposite charge under several hours of stirring causes them to be connected and attracted to each other through electrostatics.
Cement paste with a water-to-cement ratio of 0.38 was prepared and hydrated for different durations (7, 14, and 28 days). Nanostructured reinforcement with a fixed concentration of 0.05 wt.% GO and varying concentrations of 0.5, 1, and 1.5 wt.% TiO2 were added to the cement. The resulting cement paste samples were analyzed for compressive strength, porosity, and microstructure. The study revealed that the sample containing 1 wt.% TiO20.05 wt.% GO exhibited the best mechanical behavior, with a 55% higher compressive strength compared to the unreinforced cement sample. Furthermore, this sample had the lowest porosity. Microstructural analyses indicated that the reinforced sample had a reduced porosity, improved hydration acceleration, and enhanced overall integrity of the structure, leading to the significant improvements in its mechanical properties.

Keywords

Subjects


1. T. Mendes, D. Hotza, and W. Repette, "Nanoparticles in cement based materials: a review", Reviews on Advanced Materials Science, 40, 89-96, 2015.
2. S. Maheswaran, B. Bhuvaneshwari, G. Palani, R. Nagesh, S. Kalaiselvam, "An overview on the influence of nano silica in concrete and a research initiative", Research Journal of Recent Sciences, 2, 17-24, 2013.
3. A. Romani, "Graphene oxide as a cement reinforcing additive, preliminary study", MSC Thesis, Politecnico Di Milano, 2015.
4. G. Bastos, F. Patiño-Barbeito, F. Patiño-Cambeiro, J. Armesto, "Nano-Inclusions Applied in Cement-Matrix Composites: A Review", Materials, 9, 1015, 2016.
5. Z. Metaxa, M. Konsta-Gdoutos, S. Shah, "Carbon nanofiber-reinforced cement-based materials", Transportation Research Record: Journal of the Transportation Research Board, 114-118, 2010.
6. M. J. Hanus, A. T. Harris, "Nanotechnology innovations for the construction industry", Progress in Materials Science, 58, 1056-1102, 2013.
7. M. I. Katsnelson, "Graphene: carbon in two dimensions", Materials Today, 10, 20-27, 2007.
8. C. Lin, W. Wei, Y. H. Hu, "Catalytic behavior of graphene oxide for cement hydration process", Journal of Physics and Chemistry of Solids, 89, 128-133, 2016.
9. L. Tang, J. Liu, N. Wang, L. Ye, "Pre-Study of Graphene-Enhanced Cementitious Materials", Technical Report, Chalmers University of Technology, 2014.
10. Q. Wang, J. Wang, C. Lu, B. Liu, K. Zhang, C. Li, "Influence of graphene oxide additions on the microstructure and mechanical strength of cement", New Carbon Materials, 30, 349-356, 2015.
11. A. Nazari, S. Riahi, S. Riahi, S. F. Shamekhi A. Khademno, "Assessment of the effects of the cement paste composite in presence TiO2 nanoparticles", Journal of American Science, 6, 43-46, 2016.
12. L. Wang, H. Zhang, Y. Gao, "Effect of TiO2 nanoparticles on physical and mechanical properties of cement at low temperatures", Advances in Materials Science and Engineering, Article ID 8934689, 2018.
13. S. I. Ghazanlou, M. Jalaly, S. Sadeghzadeh, A. H. Korayem, "High-performance cement containing nanosized Fe3O4–decorated graphene oxide", 260, 120454, 2020.
14. L. Zhao, X. Guo, C. Ge, Q. Li, L. Guo, X. Shu, et al., "Mechanical behavior and toughening mechanism of polycarboxylate superplasticizer modified graphene oxide reinforced cement composites", Composites Part B: Engineering, 113, 308-316, 2017.
15. X. Li, A. H. Korayem, C. Li, Y. Liu, H. He, J. G. Sanjayan, et al., "Incorporation of graphene oxide and silica fume into cement paste: A study of dispersion and compressive strength", Construction and Building Materials, 123, 327-335, 2016.
16. X. Li, Z. Lu, S. Chuah, W. Li, Y. Liu, W. H. Duan, et al., "Effects of graphene oxide aggregates on hydration degree, sorptivity, and tensile splitting strength of cement paste", Composites Part A: Applied Science and Manufacturing, 100, 1-8, 2017.
17. S. Sharma, N. Kothiyal, "Influence of graphene oxide as dispersed phase in cement mortar matrix in defining the crystal patterns of cement hydrates and its effect on mechanical, microstructural and crystallization properties", RSC Advances, 5, 52642-52657, 2015.
18. M. E. Abrishami, V. Zahabi, "Reinforcing graphene oxide/cement composite with NH2 functionalizing group", Bulletin of Materials Science, 39, 1073-1078, 2016.
19. T. M. Fayyad, J. M. Lees, "Experimental investigation of crack propagation and crack branching in lightly reinforced concrete beams using digital image correlation", Engineering Fracture Mechanics, 182, 487-505, 2017.
20. J. Beaudoin, P. Gu, R. Myers, "Flexural strength of cement paste composites containing micron and sub-micron nickel particulates", Cement and concrete research, 27, 23-27, 1997.