COMPOSITE BEAM AND PCa COMPOSITE BEAM MEMBER CONSTITUTING THE SAME, AND COMPOSITE RIGID-FRAME STRUCTURE

摘要

PROBLEM TO BE SOLVED: To narrow a cross sectional area of a beam or improve its strength to secure fire resistant performance, and effectively prevent occurrence of cracking.SOLUTION: A composite beam 2 includes: a beam center part 21 made of high strength concrete and arranged in a sectional center part; and a beam peripheral part 22 made of concrete having a higher water cementitious material ratio and lower strength than those of the high strength concrete and arranged in a peripheral part of the sectional area so as to cover the whole peripheral surface of the beam center part 21. The composite beam 2 is constituted to have a beam main reinforcement 26 and a stirrup 27 arranged only in the beam peripheral part 22.SELECTED DRAWING: Figure 5