of the u03b3 elements centralizing and positioning them in fig2 one sees a further variant of base module u03b3 the wings of this element present a plurality of upstanding ribbing projections 109 that can extend partially or through the complete length of the wings these ribbing projections 109 give origin to an analogous plurality of ducts recesses 110 which can constitute both the seating place of reinforcement and seatings of passage of service installations fig2 represents an example of assemblage of a u03b3 element with a first execution form of wall beam the latter is composed by a vertical slab form 111 that at its height presents two projection ribs 112 and 113 rib 112 being lowered with respect to rib 113 that form between them a longitudinal seat or recess 114 the wing 103 b of element u03b3 surmounts the lowered projection rib 112 and there rests as can more clearly be seen in fig2 the longitudinal seating or recess 114 will include a reinforcement steel cage and a joining casting beam of the structure in the case of not wanting to surmount wing 103 c fig2 the wall beam 111 c will have two projection ribs 112 c and 113 c of equal dimensions still presenting a longitudinal seat or recess 114 c in fig2 a further variant of the wall beam is represented in this case the zone presenting the seating or recess 114 d is prolonged in relief for an interval 115 of length equal to the lesser wing of the element u03b3 to which it will be put side by side in this way foreseeing a lateral opening 116 it is possible to carry the beam perimetrically in respect to the element u03b3 in fig2 the preparation of a connection casting.