The improvement of mechanical properties of conventional concretes using carbon nanoparticles using molecular dynamics simulation
Authors: Mahyuddin K M Nasution
As&#x27;ad Alizadeh
Maboud Hekmatifar
Teimour Ghahari Iran
Davood Toghraie
Roozbeh Sabetvand
Liang Zhao
Pavel Kamenskov
Journal: Scientific Reports (2021)
Discipline: Multidisciplinary
Keywords: mechanical properties; carbon nanoparticles; concrete matrix; molecular dynamics method; stress-strain diagram
Affiliations: School of Civil and Architectural Engineering, Yangtze Normal University, Chongqing, 408100, China. ., DS & CI Research Group, Universitas Sumatera Utara, Medan, Indonesia., Department of Mechanical Engineering, Khomeinishahr Branch, Islamic Azad University, Khomeinishahr, Iran., Department of Energy Engineering and Physics, Faculty of Condensed Matter Physics, Amirkabir University of Technology, Tehran, Iran., Department of Propaedeutics of Dental Diseases, Sechenov First Moscow State Medical University, Moscow, Russia., Department of Mechanical Engineering, Khomeinishahr Branch, Islamic Azad University, Khomeinishahr, Iran. ., Department of Mechanical Engineering, Urmia University, Urmia, Iran.

Abstract:  In the present study, the improvement of mechanical properties of conventional concretes using carbon nanoparticles is investigated. More precisely, carbon nanotubes are added to a pristine concrete matrix, and the mechanical properties of the resulting structure are investigated using the molecular dynamics (MD) method. Some parameters such as the mechanical behavior of the concrete matrix structure, the validation of the computational method, and the mechanical behavior of the concrete matrix structure with carbon nanotube are also examined. Also, physical quantities such as a stress-strain diagram, Poisson's coefficient, Young's modulus, and final strength are calculated and reported for atomic samples under external tension. From a numerical point of view, the quantities of Young's modulus and final strength are converged to 35 GPa and 35.38 MPa after the completion of computer simulations. This indicates the appropriate effect of carbon nanotubes in improving the mechanical behavior of concrete and the efficiency of molecular dynamics method in expressing the mechanical behavior of atomic structures such as concrete, carbon nanotubes and composite structures derived from raw materials is expressed that can be considered in industrial and construction cases. 

Retracted: No

PubPeer comments:
 The data claimed in **Table 1 (Lennardu2013Jones potential coefficients are used in this study)** are not supported by any references. ![file] ![file] ![file] References [28] and [29] were also checked, but none of the data claimed in Table 1 were found in these two references: ![file] , 
 **The formula (2) was not found in the claimed reference [29].** ![file] ![file] ![file] , 
 [Expression of Concern] , dated July 05, 2022. (Highlighting mine.) The Editors are issuing an Editorial Expression of Concern to alert readers that this article shows substantial indication of **irregularities in authorship during the submission process**. Readers should also note that the source of the coefficients used in Table 1 was omitted and is Rappu00e9 et al. 1992 [1]. Davood Toghraie agrees with this statement. Liang Zhao, Mahyuddin K. M. Nasution, Maboud Hekmatifar, Roozbeh Sabetvand, Pavel Kamenskov, Asu2019ad Alizadeh Teimour Ghahari Iran have not responded to correspondence about this statement. [1] Rappu00e9, A. K., Casewit, C. J., Colwell, K., Goddard, W. A. III. Skiff, W. M. UFF, a full periodic table force field for molecular mechanics and molecular dynamics simulations. J. Am. Chem. Soc. 114(25), 10024u201310035 (1992). , 
 From an atomic point of view, carbon nanotubes are cylindrical molecules with open or closed ends. In general, carbon nanotubes can be divided into three general categories: zig-zag carbon nanotubes, chiral carbon nanotubes and armchair carbon nanotubes [6, 7]. [6] Muhammad Adnan, A. A theoretical study of the size effect of carbon nanotubes on the removal of water chemical contaminants. J. Res. Sci. Engi. Technol.6(04), 21u201327 (2018). [7] Aghili, A., Kamrani, M.R. Modeling of the thermal degradation of poly (methyl methacrylate) and its nanocomposite with multi-walled carbon nanotubes. Adv. Appl NanoBio-Technologies.2(3), 22u201334 (2021). Of the  three general categories, [6] mentions none, [7] mentions only armchair nanotubes. These references do not appear very relevant to the specific context in which they are cited. , 
 In addition to the molecular dynamics method, there are other methods for studying micro- and nano-scale currents [19,20,21]. [19] Zajmi, L., Ahmed, F.Y., Jaharadak, A.A. Concepts, methods, and performances of particle swarm optimization, backpropagation, and neural networks. Appl. Comput. Intell. Soft Comput.. https: doi.org 10.1155 2018 9547212 (2018). [20] Tjahjono, T., Elveny, M., Chupradit, S., Bokov, D., Hoi, H. T., Pandey, M. Role of cryogenic cycling rejuvenation on flow behavior of ZrCuAlNiAg metallic glass at relaxation temperature. Trans. Indian Inst. Met.https: doi.org 10.1007 s12666-021-02395-3 (2021). [21] Ozkaya, S.G., Baygin, M., Ozdemir, M.A., Kazaz, I. Image processing based analysis of the compressive strength for the stones used in historical masonry structures. Int. J. Comput. Sci. Software Eng..6(10), 216u2013222 (2017). No obvious relevance of these references to  micro- and nano-scale currents, whatever that means, nor to the topic of the study. , 
 By done these final calculations, we conclude simulated structures in current computational work can be used in actual applications [35, 36, 37, 38, 39]. [35] Alirezaie, A., Hajmohammad, M.H., Hassani Ahangar, M.R., Esfe, M.H. Price-performance evaluation of thermal conductivity enhancement of nanofluids with different particle sizes. Appl. Therm. Eng..128, 373u2013380 (2018). [36] Oveissi, S., Eftekhari, S.A. Toghraie, D. Longitudinal vibration and instabilities of carbon nanotubes conveying fluid considering size effects of nanoflow and nanostructure. Physica E.83, 164u2013173 (2016). [37] Hemmat Esfe, H., Bahiraei, H., Mahian, O. Experimental study for developing an accurate model to predict viscosity of CuOu2013ethylene glycol nanofluid using genetic algorithm based neural network. Powder Technol.338, 383u2013390 (2018). [38] Esfe, M.H., Karimpour, R., Abbasian Arani, A.A., Shahram, J. Experimental investigation on non-Newtonian behavior of Al2O3 -MWCNT 5W50 hybrid nano-lubricant affected by alterations of temperature, concentration and shear rate for engine applications. Int. Commun. Heat Mass Transfer.82, 97u2013102 (2017). [39] Esfe, M.H., Abbasian Arani, A.A., Firouzi, M. Empirical study and model development of thermal conductivity improvement and assessment of cost and sensitivity of EG-water based SWCNT-ZnO (30%:70%) hybrid nanofluid. J. Mol. Liq.244, 252u2013261 (2017). It is unclear what the above sentence means. What is clear, however, is that studies of rheological characteristics of nanofluids are irrelevant in the present study. Four of the five references are to the benefit of a certain MH Esfe, the remaining one is a self-citation to one of the co-authors, a certain D Toghraie. , 
 Equation (3) of this paper is nonsense. ![file] The correct form from ref. [30] is as follows: ![file] --- ![file] , 
 A Tersoff potential involves three-atom interactions. It would be helpful to know to which triples in the system it is applied, and what are the constituent parameters. Is Tersoff potential applied on top of the Lennard-Jones, instead of Lennard-Jones, or else? Overall, could the authors provide the full LAMPPS input? ![file] ,