Reinforced concrete construction

Claim 1

A concrete panel suitable for incorporation into a composite concrete two-way slab system, which comprises: a generally planar relatively thin sub-slab having a generally flat upper surface; a series of reinforcing bars embedded within said sub-slab and extending transversely substantially entirely thereacross and in a generally parallel alignment with each other; each of said bars having two end portions and an intermediate portion therebetween; the intermediate portion of each of said bars being wholly embedded in said sub-slab and lying generally parallel and adjacent to said lower surface; each of said end portions being bent upward in a continuous curve through an angle of at least 180° with the center point of the bend being above the upper surface of said sub-slab and the lower portion of said continuous curve being embedded in said sub-slab; the length of the free portion of each of said end portions being equal to at least six times the diameter of the bar; and the height of said bend being sufficient to provide a confined bearing load to concrete filled within the bend in a composite system lower than the allowable confined bearing load of the concrete fill.