In this book, mathematical modelling and numerical study of concrete beams with nanoparticles in structures are presented. The main purpose of this book is discussing about various theories of beams for static and dynamic analysis. This is an essential and basic book for Msc. and PhD. students for developing their works in the field of mathematical modelling and numerical study of structures. Here, various theories of beams such as classical, Timoshenko, sinusoidal and higher-order are presented. Due to using nanoparticles in concrete beam, different models are discussed for obtaining the effective material properties of nanocomposite structures such as Mori-Tanaka, mixture, micro-electromechanical and Halpin-Tsai. This book can be further developed for concrete plates and shells.