The evaluation of the dynamic modulus of elasticity of twelve different concrete mix proportions as a function of the density and degradations due to freeze/thaw cycles is presented in this paper. Pore system and saturation are the main factors for concrete freeze-thaw resistance. The frequency analysis of ultrasonic waves in concrete after every 25 cycles was done. Dynamic modulus of elasticity was determination by resonance frequency analysis. This parameter is 35-50% smaller for concrete with recycled bricks as aggregate than ordinary concrete. For all concrete mixes dynamic and static (measured by destructive testing) modules of elasticity were compared.