Abstract
The tensile stress and shearing stress on the interface between the GRC casting forms and the concrete of the reinforced beam during fires were calculated by finite element method. Two types of GRC casting formworks were selected to improve joining performance between GRC and concrete. One was putting embossment and the other was burying wire net on the inside surface of GRC casting formworks. Fire resistance test was carried out on reinforced concrete beams covered with these GRC casting formworks and also to the reinforced concrete beam without GRC formwork. From these tests it was recognized that GRC formwork in which wire net was buried showed good joining performance between GRC and concrete. GRC formwork which has embossment on inside surface showed a little separation because the ascent of the temperature of the steel showed lower than in the other specimens and this fact was confirmed by the inspection of the specimen after the heating test but it was not so serious. It can be considered that RC beams using GRC permanent formworks have the similar degree of fire resistance properties with the conventional RC beam without formworks.
