Abstract: Based on the simulation technique of concrete mesostructure,a Monte Carlo’s approach is presented for the calculation of the area fraction of interfacial transition zone in concrete.Calculated results demonstrate that the area fraction of interfacial transition zone increases,for a given aggregate area fraction,with the decrease of the minimum aggregate diameter and increases,for a given minimum aggregate diameter,with the increase of the aggregate area fraction.By applying mathematical regression,a simple calculation formula of the area fraction of interfacial transition zone is given.

Key words: interfacial transition zone, computer simulation, concrete, Monte Carlo&rsquo, s approach