Design of partially prestressed beams using programmable calculators

This paper discusses the principles for use of programmable pocket calculators in the design of partially prestressed beams. The proposed algorithm is in accordance with both the strength and serviceability criteria of the ACI-318 building code. The program presented in this pocket paper is developed for use in the TI-59 programmable calculator. Magnetic cards are used for storage of program steps. The program steps are presented in four sets. The first set of steps deal with the design of the beam cross section, and the calculation of the areas of nonprestressed and prestressed steel; using the strength design approach. The second set deals with the calculation of the cracking moment capacity of a given beam. The third and fourth set of program steps deal with the calculation of material stresses. If a designer chooses to analyse a beam of his own choice, he can use the appropriate set of program steps. In other words design and analysis can be done independently. For each group of program steps flow charts are provided to illustrate the sequence of calculations. Design examples are worked out to illustrate the input/output data.