Patent ID: 7770250

Claim:
A concrete building system comprising: a set of parallel spaced apart strip footers; one or more precast concrete sections supported by the footers in predetermined alignment; each precast concrete section having a top slab integrally connected to a pair of flared legs, the top slab having a uniform thickness, an inner surface, an upper surface, a first end and a second end, the distance between the first end and the second end defining an effective span; each leg having a length, a uniform thickness, an inner surface, an outer surface, a top portion and a bottom portion, the bottom portion being supported by a footer and the distance between the bottom portions of the legs defining a bottom-of-leg span; each leg depending from an end of the top slab at an effective flare angle to form a corner; a pair of haunch sections; each haunch section being integrally formed between the top slab and one of the legs whereby the haunch section extends from the inner surface of the top slab near an end to the inner surface of the top portion of the leg nearest that top slab end and results in a corner thickness greater than the uniform thickness of the top slab and the leg to which it is integrally formed; a rise defined by the vertical distance between the bottom portion of the flared legs and the inner surface of the top slab; and the length of the effective span being between 60 and 90 percent of the bottom-of-leg span.