CONCRETE

[:ru]Кларк Г.[:en]Clark, G.[:] [:ru]президент fib (Международная федерация железобетона); директор Ramboll Group AS, Великобритания[:en]President, fib (the International Federation for Structural Concrete); Director, Ramboll Group AS, UK[:]

Alitinform №4-5 (31) 2013 г. 62-71 p.

Abstract

Post-tensioned concrete bridges are now subject to significant scrutiny by owners, designers and maintaining authorities as a result of some defects appearing in their original construction. These defects are mainly related to poor grouting or corrosion protection of the prestressing tendons, but some are a result of poor design details and workmanship aspects of their construction. Many of these structures are now more than 50 years old and their condition, and their ability to last for many years, is crucially dependant on the quality of protection to the prestressing tendons, which needs to be assured as it can be very variable.
Significant inspection programmes have been carried out in many countries of the world to investigate these defects, and to prepare repair and management plans. This paper describes some experiences from such inspections carried out by Ramboll and others and some of the resulting action taken to repair or replace the structures. Significant lessons have been learnt and whilst current design and construction standards have been improved, there are experiences to share from which further international research and improvement can be considered.

Key words:

prestressed concrete; grouting; tendons; concrete corrosion