In general the ultimate strength of reinforced concrete slabs shows larger values than the bending strength obtained from the yield line theory of Johansen. The cause of this difference is explained as an arching action due to the development of compression membrane forces in the slab. Relevantly in this report we describe the derivation of equations of load-deflection curves capable of reflecting the degree of restraint of both rotation and horizontal movement of- edge-restrained reinforced concrete slabes. Then we compare the curves resulting from the equations with experimental curves. As a result, the curve of calculated values is generally in a fairly good agreement with the curve of experimental values.
