Discussion and Application of the Friction of Extra Long Prestressed Tendons with the Wall of Duct

Based on the analysis of a great number of data from site tests and with reference to relevant research works at home and abroad, the friction factor of extra long prestressed tendons with the wall of duct is presented. The effect on the friction factor μ, which is caused by the stress level of prestressed tendons, is also discussed. The suggested measures in the conclusion may be taken as important referential materials to the design and construction of extra long prestressed concrete structures.