Mathematical expressions from national codes show that concrete elastic modulus is a function of concrete compressive strength. But concrete, regarded as a three-phase composite material, has elastic properties directly affected by the interfacial transition zone (ITZ), which is characterized by its higher porosity in comparison to the cement paste. Micromechanical models such as the Mori-Tanaka and three-phase sphere may be applied with good results when used to analyze the concrete. This paper presents a study on the evolution of the concrete elastic modulus, this study is carried out by the application of normative expressions and micromechanics models. Compared to the experimental results, a good fitting of micromechanical modeling with ITZ included is observed. Additionally, the quality of the NBR 6118:2003 and CEB-90 expressions is confirmed.
concrete; elastic modulus; normative expressions; micromechanic; interfacial transition zone