Abstract
Existing study far fire-resistant concrete has been done already. but it is not found out how the waste tyre mixing concrete will be acted against fire. This waste tyre concrete molds under the condition of $0^{\circ}C,\;200^{\circ}C,\;400^{\circ}C,\;600^{\circ}C$ were heated in gas oven. It was worried about that they might be fractured down at about $800^{\circ}C$ so that they can not be tested. compressive strength for the test molds are made with commercially used $180kg/cm^2,\;210kg/cm^2,\;240kg/cm^2,\;270kg/cm^2$ mixing saw dust with proportion such as 0.05%, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0% compressive strength at $200^{\circ}C$ was approximately 20% from the original, while approximately 30% deoreased at $400^{\circ}C$. their results are not quite different from the normal concrete condition even though they contains saw dust in it. The higher strength the concrete has, the less strength was decreased. There are almost no difference in strength under the condition of less than $400^{\circ}C$, but damage of concrete structure could be considerable large with more than $400^{\circ}C$.