Abstract
In this paper, we propose a method to evaluate the distribution of dynamic elastic modulus of prismatic concrete specimen with square cross-section based on two different vibration modes by resonance method. We often have experiences that the dynamic elastic modulus obtained from longitudinal vibration is higher than that of flexural vibration on the deterioration test. We assume that the difference is due to the distribution of the dynamic elastic modulus produced inside the specimen. The influences of the distribution on the dynamic elastic modulus are different between the longitudinal vibration mode and the flexural vibration mode. We make models of the concrete specimen that dynamic elastic modulus varies toward the inside of the specimen linearly, and simulate such vibration modes of the specimen, the longitudinal, flexural and torsional vibrations by dynamic finite element method. We derive an approximate expression to evaluate the distribution of the dynamic elastic modulus in terms of the frequencies of the flexural and longitudinal vibrations.
