PURPOSE: To improve durability by doubly arranging reinforcing bars for shearing of short span beams.

CONSTITUTION: Beam main reinforcements 3 of beams in short spans made of reinforced concrete are constrained by the reinforcing bars for shearing 4. Closed type reinforcing bars for shearing 5 or spiral type reinforcing bars for shearing are disposed doubly on the outer circumferences of the reinforcing bars for shearing 4. Flat bars are buried to the upper and lower sections of the reinforcing bars for shearing 4 respectively while the flat bars may also be connected by a long bolt mutually. Concrete is placed, and a beam 2 is constructed while the slits 6 of concrete are formed to the connecting end faces of columns 1 and the beam 2. Accordingly, shear rupture is prevented in the short-span beam made of reinforced concrete, and rupture in bending, in which the short-span beam is broken gradually, can be generated even when the short- span beam is broken while adhesive cleavage yield strength required for a reinforced-concrete ultimate-degree type design can be increased.