Abstract:
A bar arrangement and anchorage structure of a concrete filled steel tube column and a reinforced concrete flat plate having a shear head is provided to arrange and anchor reinforcing bars of a reinforced concrete flat plate to a concrete filled steel tube column stably, and to shorten a period of construction and to increase the efficiency of a joint by reducing a field work. A bar arrangement and anchorage structure of a concrete filled steel column and a reinforced concrete flat plate having a shear head is used for anchoring reinforcing bars(22) of a reinforced concrete flat plate, to a concrete filled steel tube column(10) which is composed of a steel tube having a hollow and filled with concrete in the hollow, wherein a shear head(11) composed of a beam member to be buried under the reinforced concrete flat plate is integrated to the concrete filled steel tube column at the side of the concrete filled steel tube column, on a joint between the concrete filled steel tube column and the reinforced concrete flat plate, holes are formed to face each other on the outer circumferential surface of the concrete filled steel tube column to make the reinforcing bars of the reinforced concrete flat plate penetrate the concrete filled steel tube column, and the reinforcing bars of the reinforced concrete flat plate are inserted to the holes at the outside of the concrete filled steel tube column and arranged to pass through the facing holes via the inside of the concrete filled steel tube column to have shear resistance with the combination of the outer circumferential surface of the concrete filled steel tube column and the anchor end of the reinforcing bar, and shear resistance with interaction between the reinforcing bar and the concrete filled in the column, thereby to prevent the shear failure of the reinforced concrete flat plate structure.
Abstract:
A joint structure between a CFT(concrete filled steel tube) column and a RC(reinforced concrete) flat plate with a compression zone reinforced by high-strength concrete is provided to transfer shear force by load added on a slab to a CFT column between a CFT column and a RC flat plate and to secure sufficient stability against punching shear. The invention relates to a joint structure between a CFT(concrete filled steel tube) column(10) composed of a steel pipe having a hollow and filled with concrete(1) in the hollow and a RC(reinforced concrete) flat plate(100) composed of a reinforced concrete slab, wherein a compression zone(200) on a joint between the CFT column and the RC flat plate is made of high strength concrete having the larger strength(42Mpa~80Mpa) than the strength of ordinary concrete on another zone of the RC flat plate to increase punching shear strength, deformation capacity and energy absorption capacity. In addition, a shear head(20) composed of a steel beam is installed on the side of the CFT column integrally to be buried under the RC flat plate on a joint between the CFT column and the RC flat plate to push out the dangerous cross section of punching shear, thereby to increase stability against the punching shear, and a horizontal support member(30) composed of a beam is connected between shear heads of the adjacent CFT columns to support each CFT column, thereby to secure stability of the CFT column while erecting a CFT column or performing successive construction and to function as a suspension member when punching shear failure occurs on the RC flat plate, thereby to prevent the chain breakdown of buildings.
Abstract:
A joint structure of a concrete filled steel tube column and a reinforced concrete flat slab using a shear head is provided to maximize merits of a CFT(concrete filled steel tube) column and merits of a joint structure of a RC(reinforced concrete) flat slab, to transfer shear force by load added on a slab between a CFT column and a floor slab and to secure sufficient safety against punching shear. A joint structure of a CFT(concrete filled steel tube) column and a RC(reinforced concrete) flat slab using a shear head is formed by installing a shear head(20) composed of a beam having the appointed length to be buried under a RC flat slab on a joint of a CFT column(10) composed of a steel tube having a hollow(12) filled with concrete(1) and a RC flat slab composed of reinforced concrete slab. The shear head is fixed to a joint(15) formed on the side of the CFT column integrally to be projected in the direction of the RC flat slab as much as the distance from the front of the CFT column to a critical section of punching shear calculated by a plan, so that the critical section of punching shear on the joint structure of the CFT column and the RC flat slab is located on the outside of an end of the shear head.