Title: Softening of Concrete in Torsional Members- Prestressed Concrete
Author(s): Thomas T. C. Hsu and Y. L. MO
Publication: Journal Proceedings
Appears on pages(s): 603-615
Keywords: angle of twist; beams (supports); building codes; compressive strength; computer programs; cover; cracking (fracturing); prestressed concrete; reinforced concrete; shear properties; stress-strain relationships; structural design; thickness; torsion.
Based on equilibrium and compatibility conditions, as well as a new stress-strain relationship for softened concrete, a new truss model theory for nonprestressed concrete was presented in the first paper of this series. This model accurately predicts the torsional behaviors of 108 test beams available in the literature. The design recommendations for nonprestressed concrete was proposed in the second paper of this series. In this third paper of the series, the truss model theory developed for nonprestressed concrete members is extended to include uniformly prestressed concrete by using the concept of the decompression of concrete for prestressing steel. This generalized theory accurately predicts the torsional behavior of 50 uniformly prestressed concrete test beams available in the literature. A set of tentative design recommendations is proposed for prestressed concrete members subjected to torsion.