抄録
The plastic design methods of reinforced concrete slab have been based on Johansen's yield-line theory. However, A. J. Ockleston found that ultimate strength obtained by his experimental studis reached several times the calculated value by the yield-line theory, and this difference was due to the arching action in the slab. In this paper on reinforced concrete square slabs with four edge beams, the influences of the rigidity of edge beams, and the thickness of slab on elastic and plastic behavior of slab, especially mechanism of failure, ultimate strength and arching action were discussed. For this purpose four square slabs were tested and the next results were obtained. 1) In the case of a slab, even if flexural rigidity of edge beams is considerably large, the elastic deflection is large as compared with four-edge-clamped slab. 2) The slabs are divided into four triangular parts by the diagonal cracks at the final failure stage. 3) The ultimate strength of square slab with edge beams is far in excess of that predicted by Johansen's yield-line theory considering only the bending strength and the main reason for this is the arching action induced in the slab. 4) The effect of arching action in slab has a tendency to be large, when the thickness of slab is large, the edge beam is rigid.
