抄録
FRP panel materials that contribute to the drastic weight reduction of slabs for high-rise buildings were designed. To comply with building codes, materials must pass the 2-hour fire test per ISO834. As a strategy for that, firstly the structure where a foam core material is sandwiched between FRP skin layers and the outermost surfaces are covered with fire-resistant covering materials such as gypsum board was proposed. In that case, the FRP skins as well as the foam core are never exposed to flames directly whereas the temperature of FRP skins rise up to around 200 ℃ due to heat conduction somewhat reduced by the fire-resistant covering materials in case of fire. Therefore, the FRP skin should have a glass transition temperature (Tg) of at least 250°C or higher to support the load. So, secondly, we proposed a new resin system that gives a high Tg and can be molded by an ordinary molding process. Some kind of poly-functional acrylic resins with a rigid backbone have relatively low viscosity and can be cured at moderate temperature in the presence of an organic peroxide and a reductant, which means it is applicable to VaRTM as matrix resin. Moreover, after curing, the resin exhibited Tg-less thermal properties that means it is always in the glassy state and has high moduli in the whole temperature range below its thermal decomposition temperature. The CFRP specimen with this newly developed Tg-less acrylic resin as the matrix exhibited a flexural modulus of 18 GPa even at 300°C, which was equivalent to as much as 82% of the flexural modulus at 30°C.
