Abstract
Clay roofing tiles have been widely used for roof of detached houses. After the Hanshin·Awaji great earthquake, there is a sharp decrease in demand for clay roofing tile, because it's weight per unit area is the heaviest among all kinds of roofing materials. In the development of a light clay roofing tile with high mechanical strength, it is not convenient to use raw materials of high grade due to an increase of the production cost. In this study, the usually employed raw materials, which contained a large fraction of quartz grains with large size, were ground by wet ball milling, and the influence of the maximum quartz grain size on the mechanical strength of the roofing tile bodies was studied. Upon grinding the quartz of raw material to a smaller grain size, a roofing tile body with high mechanical strength could be obtained. The flaw size for mechanical strength of the roofing tile body seems to mainly depend on the maximum quartz grain size.
