Using mold specimens according to JASS 5N T-601, and core specimens taken from the walls specimens, experiments investigating the effect some factors, such as the specimen size, water-binder ratio and cement type on the dry density were carried out. Then a testing method for the measuring dry density of shielding concrete was examined by using the core specimens. As a result, by using the core specimens taken from existing concrete structures, the authors could measure the dry density of shielding concrete based on the method of JASS 5N T-601.
