Report R 74 Prestressed concrete - friction losses during stressing

Publication Year

1978

Document Status

Current

Abstract

The Report presents a review of information and data on factors influencing friction losses during prestressing and draws particular attention to two very important factors: workmanship and tendon surface condition. In Part 1, the available data on friction coefficient and 'wobble' factor are examined and values are proposed for use in design. Some further test results examining the effects of tendon type and surface condition are presented in Part 2. Part 3 summarises tests undertaken to examine the effect on serviceability and ultimate load of beams with incomplete bond between tendon and grout, arising, for example, from incomplete removal of a protective oil film applied to a tendon. Part 4 is a guide to good practice in post-tensioned concrete construction and includes precautions to be taken during the storage, handling and positioning of tendons, and recommendations for site tensioning and for subsequent grouting operations.

ISBN

9780860170662

Publisher Information