RESEARCH PAPER Concrete Pipes Reinforced with AL 2 O 3 Nanoparticles Considering Agglomeration: Magneto-Thermo-Mechanical Stress Analysis Ali Heidarzadeh 1 • Reza Kolahchi 1 • Mahmood Rabani Bidgoli 1 Received: 13 August 2016 / Revised: 12 November 2016 / Accepted: 19 November 2016 Ó Iran University of Science and Technology 2016 Abstract Concrete pipes can be used in many industries which are exposed to different mechanical and thermal loadings. However, in the present work, stress analysis of concrete pipes reinforced with AL 2 O 3 nanoparticles is presented considering agglomeration effects. The pipe is subjected to mechanical, magnetic and thermal loadings. All the equivalent mechanical and thermal properties of structure are obtained using the Mori–Tanaka model. Based on the equilibrium equation, the governing equation is derived. Using an exact solution, the stresses and radial displacement distributions of the structure are calculated. Presenting the effects of AL 2 O 3 nanoparticles volume percentage and agglomeration on the stresses and radial displacement of concrete structure were the main novelties of this study. Numerical results indicate that with increasing 20% AL 2 O 3 nanoparticles volume percentage, the effective stress decreases to 84.8%. Considering 75% agglomeration of AL 2 O 3 nanoparticles leads to 19.54% increase in the effective stress of concrete structure. In addition, the dimensionless radial displacement of structure at the outer surface decreases to 92.49% with increasing 20% AL 2 O 3 nanoparticles volume percentage and increa- ses by 33.55% in the inner surface with considering 75% agglomeration effects. Keywords Concrete pipe  AL 2 O 3 nanoparticles  Mori– Tanaka model  Stress analysis 1 Introduction Nanotechnology has a significant impact on the construc- tion sector. Several applications have been developed for this specific sector to improve the durability and enhanced performance of construction components, energy efficiency and safety of the buildings, facilitating the ease of main- tenance and to provide increased living comfort. Nanoparticles of TiO 2 , AL 2 O 3 or ZnO are applied as a final coating on construction ceramics to bring this characteristic to the surfaces. Stress analyses of different structures have been studied by many researchers. Mechanical and thermal stresses in a functionally graded hollow cylinder were investigated by Jabbari et al. [1]. Analysis of the thermal stress behaviour of functionally graded hollow circular cylinders was presented by Liew et al. [2]. You et al. [3] presented elastic analysis of internally pressurized thick-walled functionally graded spherical pressure vessels. Dai et al. [4] studied exact solu- tions for functionally graded pressure vessels subjected to a uniform magnetic field. Ghorbanpour Arani et al. [5] investigated the effect of material in-homogeneity on the electro-thermo-mechanical behaviours of functionally gra- ded piezoelectric rotating shaft. Also, they [6] studied electro-thermo-mechanical behaviours of functionally gra- ded piezoelectric spheres using the analytical method and ANSYS software. Retrofit design of damaged pre-stressed concrete cylinder pipes was presented by Lee and Lee [7]. With respect to the developmental works on elastic analysis of the cylinders, it should be noted that none of the research mentioned above has considered composite & Reza Kolahchi r.kolahchi@gmail.com Ali Heidarzadeh aliheydarzade56@yahoo.com Mahmood Rabani Bidgoli rabbanee1@gmail.com 1 Department of Civil Engineering, Jasb Branch, Islamic Azad University, Jasb, Iran 123 Int J Civ Eng DOI 10.1007/s40999-016-0130-2