Abstract: To erect concrete structures, precast concrete beams are formed, columns having void spaces therein are erected and angle irons are temporarily mounted to said columns at beam level wherein said beams may be temporarily supported. At least one beam is positioned orthogonal to a column near the void in the column supported by the angle iron and cast-in-place concrete fills the void between the ends of said beams and said columns. In another embodiment, the columns are solid and the beams have openings of such a size as to fit around the columns so that they can be lowered to the proper beam height about the column and fastened, with the other ends of the beam being joined to adjacent beams.