ABSTRACT
Precast columns are the main vertical-load-carrying members in skeletal frames. The maximum axial force and bending moment carried by the column in its temporary condition may be much more onerous than in service. Column loads derived from wind loads acting on the incomplete frame, overturning moments due to spurious inclinations, or ‘lack of plumb', and imbalanced loads at beam positions. The stability of unbraced pin-jointed structures is provided entirely by columns designed as cantilevers for the full height of the structure. The line of load application is at the centroid of the flooring system. Partially braced structures are used in situations where stability walls are architecturally undesirable, or structurally unnecessary, in a certain part of a structure. The structural design of precast columns is no different to ordinary reinforced concrete columns, once the different loading history that a precast column experiences during manufacture, transportation and erection, has been catered for.
