Bond Stress of presressing Units in Posttensioned Concrete Bridges

The time between prestressing tendons and the injection of the ducts in concrete post tensioned bridges may be several weeks. During this time, it is necessary to protect tendons against weathering and atmospheric humidity. Tendons should be protected with various oil based agents, which can have influence on their bond with a construction.This paper deals with the calculation of bond stresses in post tensioned concrete bridges and will try to find out whether a lower bond capacity caused by the use of oil emulsions is sufficient or not.