Abstract
It was investigated that the applicability as aggregate for concretes of molten slag which treated the illegal dumped waste in the prefectural border between Iwate and Aomori with three facilities. According to the result of this experiment, it was showed that elution of deleterious material did not exceed soil environmental standards. Moreover, the physical properties as aggregate of these slags have satisfied many standards about application of molten slag. However, compressive strength of concrete specimen reduces by use of molten slag. The observation of the microscope showed that the slag surface is smooth. It was guessed that the roughness on the surface of slag is related to the strength reduction of concrete. Furthermore, resistance to freezing and thawing may reduce, when slag is mixed in large quantities. In this experiment, many cracks and air bubbles were seen inside the specimen before freezing and thawing test. It was thought that the resistance to freezing and thawing of concrete was inferior with the cause of these cracks and air voids.
