Prediction Of The Elastic Modulus Of Concrete With Polygonal Aggregates

Concrete is one of the most widely used building materials in civil engineering,and the elastic modulus is an important parameter for the stiffness assessment of engineering structures.Predicting the elastic modulus of concrete using theoretical methods can not only save a lot of material resources and manpower,but also reduce the influence of environmental and human factors.Therefore,by simulating the mesostructure of concrete with computer programme and by using the fast Fourier transform method,the quantitative relationships between the macroscopic elastic modulus and mesostructure of concrete are studied,which provides a theoretical basis for the optimum design of the properties of concrete.Based on the mesostructural simulation of concrete with polygonal aggregates,the fast Fourier transform method is used to predict the elastic modulus of concrete and the effects of various factors on it is analyzed.First,by introducing the periodic boundary conditions,polygonal aggregates with various sizes are generated and distributes within a square element.The mesostructure of concrete is formed by coating eachaggregate with an interfacial transition zone of thickness h.Second,a computational method is discussed for the average stress,average strain,and elastic modulus of one-dimensional bars and two-dimensional heterogeneous materials subjected to external forces.The validity of the numerical method is preliminarily verified through comparing the numerical results with the analytical solutions.Third,this numerical method is further applied to the mesostructure of three-phase concrete and the elastic modulus of concrete is obtained.By comparing the numerical results with two sets of experimental data collected from the literature,the validity of this numerical method is verified.Finally,based on numerical results,the main factors that affect the elastic modulus of concrete are discussed.