Title: Use of Large Tendons in Pre-Tensioned Concrete

Author(s): Niels Thorsen

Publication: Journal Proceedings

Volume: 52

Issue: 2

Appears on pages(s): 649-659

Keywords: no keywords

DOI: 10.14359/11622

Date: 2/1/1956

Abstract:
The use of a few large tendons in pre-tensioned concrete construction instead of many small ones, cuts field costs and simplifies design. This is especially true for heavy members. Physical properties of tendons are tabulated for average plant-produced steels based on stress-relieved and as-drawn material. Precautions and tests for evaluating tendons are discussed. It is shown that the bond in the end zones of a pre-tensioned member differs from the bond in the interior zones. Both types of bond can be determined by a curve indicating the maximum tension which can be absorbed in a tendon, without slip, at various distances from theend of a member. Methods of determining such curves or part thereof are explained. When using large tendons, secondary stresses in end zones of pre-tensioned members become important and may cause cracking if special care is not taken in the design. The use of a few general rules to prevent such cracks are indicated. A few examples of practical applications of large tendons are described Some future possibilities are discussed such as the use of bond breaking devices in end zones of pre-tensioned members and curved tendons.