The maturity method based on the Arrhenius law makes it possible to predict the concrete's compressive strength, Young's modulus, tensile strength, thermal coefficient evolution in a structure on the basis of a 20 °C characterization. In this paper, The LeMaHe Inverted Siphon Project using the maturity method the maturity method in a conservative way to predict the concrete characteristics (Young's modulus, tensile strength, thermal coefficient) in situ, which are needed in cracking control simulation.