2023 Volume 18 Issue 3 Pages 239-251
The strength of construction materials at historical sites built since the Edo era was investigated using the rebound hammer test and evaluated with regard to construction age, facility usage, and kind of materials. The tested materials were rocks (andesite, granite, and sandstone) at 18 sites, concrete at 23, and brick at 9. The strength of the first strike was smaller than that obtained with subsequent hits at the same position. The strength increased by increasing the number of hits until it became constant after several strikes. The mean values and coefficient variations of the strength for stone and brick were not influenced by the age of construction or facility type. An unique relationship has been observed between unconfined compressive strength and dry density for rocks and bricks. This relationship does not depend on the rock type of stone or on the ordinary, burned, or refractory bricks of the bricks.
