| 摘要 |
PROBLEM TO BE SOLVED: To improve deformation capability and eliminate the risk of causing internal cracks and the subsequent occurrence of explosion rupture even in a fire by filling a steel pipe with concrete where steel fibers longer than the standard maximum aggregate particle size by a specified value are mixed. SOLUTION: A steel pipe 1 is filled with concrete 6 where steel fibers longer than standard maximum aggregate particle diameter by 0-5mm. The mixing rate of steel fibers ranges from 0.2% to 1.0% to the volume of concrete 6. The hole diameter of a concrete placing hole 3 of a diaphragm 2 provided in the steel pipe l is 120mm or more and 18% or more the concrete 6 sectional area. Further, the hole diameter of air vent holes 4... provided in the diaphragm 2 is larger than the length of the steel fiber by 20%. Thus, it is possible to eliminate the fear of blocking the placing holes 3 of the diaphragm 2 provided in the steel pipe 1 and improve the deformation capability, thereby eliminating the risk of internal cracks and the subsequent occurrence of explosion rupture even under the high temperature condition. |
