| 摘要 |
<p>PROBLEM TO BE SOLVED: To simplify work for preventing damages due to heating from outside by laying heat insulation layer over a layer in corporating a heat absorbing material containing moisture in a bag and a heat insulation layer blocking vapor around the outer periphery of a cable protection pipe. SOLUTION: A first heat insulation layer 3 is provided on the outer periphery of a cable protection pipe 1 built in a communication cable 2, and heat resistant films 3a, 3b prohibiting the passage of steam are formed on the inner and outer surfaces of this heat insulation layer 3. At the outer side of a heat resistant film 3b, a heat absorbing material 12 formed with a number of bags 11 containing moisture 10 comprising a liquid or a gelled substance is provided, and a second heat insulation layer 13 is provided on its outer periphery. If a fire from the outside spreads to the surface of the fireproof heat insulation member, heat is effectively absorbed by the moisture 10 inside the bag 11 of the heat absorbing material 12, high temperature steam occurred as a result of the breakage of a bag 11 by a pressure is prevented by the heat resistant films 3a, 3b, and the temperature rise of the cable protection pipe 1 can be prevented.</p> |
