▎ 摘　　要

NOVELTY - The girder comprises a box beam main body. The bottom board and the web board form a box chamber. An arch structure is arranged in the chamber, two arch feet of the arch structure are connected to the bottom boards, and the arch feet on both sides of the arched structure are all connected to each other. The arch structure is connected to a lower edge of the top surface of the box beam. USE - Fiber concrete box girder with arch in box chamber for bridge (claimed). ADVANTAGE - The polypropylene fiber concrete arch structure in the box chamber can provide the additional supporting point of the top plate, so that the transverse bending rigidity of top plate can be improved effectively. The transverse damage of the box beam top plate with large transverse width can be avoided. The area of the cross section of box beam can be increased. The shearing resistance of the beam is improved. The arch structure can adapt to the box chambers of various sizes. The top plate is made of graphene, fully using the graphene of high compressive resistance and tensile strength and good impermeability of the concrete, which can effectively reduce the thickness of the plate and improve the anti-cracking performance. The web plate and the bottom plate are made of steel fiber concrete. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a bridge. DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of a fiber concrete box girder. 1Comprising graphene concrete top plate 2Steel fibre concrete bottom plate 3Steel fibre concrete web 4Polypropylene fibre concrete arch structure