Practical design of prefavricated reinforced or prestressed concrete columns for industrial and commercial buildings

Abstract

An algorithm is presented for second-order-theory design of reinforced or prestressed concrete prefabricated columns of rectangular cross-section, such as are used at industrial and commercial buildings. Tge akgorithm has been implemented in a program for compatible PCs. This program facilitates the interactive design of these elements. The column can have up to six different zones with different cross-sections and reinforcements. The loads are applied to each intermediate node and can be three forces and two moments (biaxial bending). Reinforcing steel is disposed in groups of bars selected for each zone of the column from a reinforcing rtable established by the user. This table can be consulted and modified during the design. Prestressing steel can be disposed near the corners of the cross-section and is constant along the column. Time-dependent effects (creep) are taken into account by a simple, approximate method. The user can make quick trials modifying the cross-section, the number of reinforcing steel groups and the composition of each group in each zone of the column. The program shows the total amount of teinforcement and displays iformation about the validity ot failure (by resistance or by instability) of the considered design. Thus an adequate design of the column can be obtained.