Basic Prestressed Concrete Design Part 5: Calculating Strength-Basic Prestressed Concrete Design

Basic Prestressed Concrete Design - Session 5 Handout

Pdf Summary

The document provides information about the design of prestressed concrete beams. It includes lectures on the basics of prestressing, prestressing materials, simple examples, loads, code requirements, and design examples. The design procedure involves calculating the nominal and design moment strengths of the beams, determining the stress in the prestressing steel, checking service load conditions, adjusting the number of strands required, calculating prestressing loss, checking release conditions, checking ultimate load conditions, and checking shear. The document also discusses the difference between reinforced concrete design and prestressed concrete design, highlighting factors such as the shape of the stress-strain curve and the presence of compression-controlled or transition sections in prestressed beams. The stress in the prestressing steel is calculated using either the approximate method or the strain compatibility method. The document provides equations, formulas, and diagrams to aid in the calculation of stresses and moments. It also discusses the development length of the strands and the ductility provision for composite members. The design example provided demonstrates the steps involved in calculating the ultimate moment capacity of a prestressed concrete beam and checks if it meets the required capacity at different sections along the beam. The document concludes with a question-and-answer section for further clarification.

Keywords

prestressed concrete beams

design examples

stress in prestressing steel

service load conditions

ultimate load conditions

shear

compression-controlled sections

strain compatibility method

development length

ultimate moment capacity