2002 年 51 巻 10 号 p. 1123-1128
The delaminating and peeling concrete accidents for the tunnels or the bridges are the social problem in Japan. It is desirable to develop the concrete structures with high durability and high serviceability. The polypropylene fiber is believed to be one among the synthetic fiber to prevent the spalling of concrete fragment. As polypropylene fiber is elastic and flexible, it does not pierce the hands or the feet of the workers. It is easy to treat. The wide use of the polypropylene fiber is expected. However, the melting point of the polypropylene fiber is very low. It's about 160-170°C. The resistance to the fire accident of concrete with polypropylene fiber is very important for the safety of the public. In this study, the effect of temperature on the concrete strength and vapor explosion was examined. The air space by the vapored polypropylene fiber sets free vapor pressure of moisture in concrete. It is shown that the low melting point of the polypropylene fiber is not disadvantage at the fire accident on concrete structures.