PURPOSE: To improve the efficiency of the execution of work and strength by placing concrete including steel fibers with specifically set linear diameters and lengths, on deck plates laid on the upper surfaces of steel frame beams.

CONSTITUTION: Steel fibers 31 with the linear diameters of 0.3 - 1.0 mm and the lengths of 25 - 100 mm, having hooks 32 at both ends are arranged. After that, on the upper surfaces of steel frames 1, corrugated deck plates 2 finished with hook channels, embossed patterns, or the like are laid and are fixed by plug welding or the like. After that, the steel fibers 31 are mixed in concrete 3 and it is placed to specified thickness on the deck plates 2. As a result, work for arranging reinforcements in site is saved, and the efficiency of work can be improved, and bending strength is improved, and cracks can be reduced.