Research Of Micromechanics Constitutive Model Of Concrete Mixing With Superfine Particle

As the traditional construction material, concrete is widely used and can not be substituted at present. Adding a certain percent of mineral admixtures such as fly ash and sillica fume can improve the concrete strength and durability. These particles added become the sixth indispensable additional component in high performance concrete.In this treatise, concrete is taken as multilevel two-phase composite with aggregates as dispersed phase and cement paste as continuous phase or matrix in conventional micromechanics models and the interfacial transition zone (ITZ) between them was overlooked. In order to evaluate the effective elastic modulus, a three-phase sphere model is proposed and ITZ is assumed to be a uniform layer for simplicity .The three-phase sphere model is divided into two two-phase sphere models, and relations between macroscopic and microscopic mechanics parameters fields are analyzed based on the micromechanics. Micromechanics equations are established and solved by using the self-consistent method and generalized self-consistent method. The effect of such factors as the ITZ thickness, largest aggregate diameter and aggregate grading on concrete moduli is discussed.This treatise is aimed to predict effective modulus of concrete mixing with superfine particles in order to guide structure design and improve constitutive properties.