Abstract
Under high temperature laboratory conditions, the experiment followed close on the previous paper was excuted to measure the thermal conductivity of the cement-mortar and concrete which are composed of fluvial sand and gravel; Such sandy materials are prevailingly used for their aggvegates in Japan. These fundamental data are used essentially to estimate the temperature-rising in the interior of the members of the concrete structures which are on fire. The experiments show that the value of the thermal diffusivity of concrete at 700〜800℃ is reduced to one half, that is, 0.0012〜0.0013m^2/h_T while it amounts to 0.0031〜0.0033M^2/h at room temperature. In the case of light weight concrete (pumice or coal as hes concrete), its value corres ponds to about 60 perceut of that of that thermal diffusivity of the common concrete.
