In the uses of atomic energy, the protection of living from harmful radiation produced by nuclear reactions is extremely important. Gamma ray is one of the emitted radiations of high penetration power. The appropriate material for gamma-ray shielding should have a high density so one of the popular solutions is concrete. In the case of existing reinforced concrete structures with high-density concrete, a deterioration of concrete could be found so a non-destructive measurement for strength and quality of concrete becomes necessary. However, the current equations for rebound hammer and ultrasonic pulse velocity methods are derived from normal-density concrete so they might give erroneous results for high-density one. This study shows measured results of high-density concrete using barite for an improvement of current code in the future.