FraMCoS 7 2010 Jeju, South Korea

Fire resistance of tunnel concrete depending on various heating curves and fire resistance methods

This study is to investigate experimentally fire resistance characteristics of small size tunnel con- crete structure depending on types of heating curve such as RABT and RWS and fire resistance method to ob- tain safety of tunnel concrete against fire.…

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Year 2010
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Abstract

This study is to investigate experimentally fire resistance characteristics of small size tunnel con- crete structure depending on types of heating curve such as RABT and RWS and fire resistance method to ob- tain safety of tunnel concrete against fire. The fire resistance methods applied in this study include addition of polypropylene (PP) fiber, attachment of fire proof board and application of spray on materials, respectively. As for the fire resistance characteristics according to RABT heating curve, both of PP fiber addition and fire proof board attachment methods resulted in favorable spalling prevention effect, while spraying method had severe spalling over 100mm depth occurred along with exposure of structural concrete including spray coat. For the influence of RWS heating curve, although PP fiber addition had fair spalling prevention, surface of concrete was melt up to 5 mm of its thickness due to extremely high temperature. Application of spraying method re- sulted in severe spalling to the depth around 100 mm and re-bar was exposed. Attachment of the fire proof board method had no effect on spalling prevention. The fire proof board was detached from the concrete and then concrete was exposed to abrupt high temperature and severe spalling occurred. Accordingly, existing spalling prevention method including PP fiber addition and fire proof board attachment is not available under extremely high temperature exposure and it is thought that special preparations for the concrete are needed to secure stability against extremely high temperature exposure condition like RWS curve.