Prediction system for compressive concrete strength in aged structural member is proposed. This system is composed of models of rate of hydration, cement paste phase composition, heat production, specific heat, compressive strength, vapor desorption isotherm, coupled heat and moisture transfer. Each model is verified through experimental data. This system is aiming for the structural member which can not be accessed or can not be evaluated by the core sample test. Using non-destructive data or quality control sample's data, this system might illustrate the distribution and development of concrete strength in structural member properly. From the calculation results for a concrete member exposed to high temperature condition, strength development as well as distribution is quite sensitive to the boundary condition, and this concludes that the evaluation of structural member under such special condition needs precise boundary conditions.
