Bibliography: p. 6.
|Other titles||Unbonded tendons.|
|Statement||[FIP Commission on Prestressing Steels and Systems, Ad-Hoc Committee on Durability of Unbonded Tendons].|
|LC Classifications||TA445.5 .F43 1986|
|The Physical Object|
|Pagination||6 p. ;|
|LC Control Number||86670098|
Protective coating Sheathing Sheathing inspection After the tendon has been installed in the formwork, and before concreting begins, the sheathing for each tendon should be inspected for possible damage. Any large damaged areas should be cleaned and the strand inspected for damage or corrosion. Ad-Hoc Committee on Durability of Unbonded Tendons. Corrosion protection of unbonded tendons. London: T. Telford, (OCoLC) Document Type: Book: All Authors / Contributors: Fédération internationale de la précontrainte. Commission on Prestressing Steels and Systems. Ad-Hoc Committee on Durability of Unbonded Tendons. ISBN. A-Z of books and conference proceedings; About our eBooks; ICE bookshop; Book series; Subjects. All Subjects; Buildings and structures; Coastal and offshore engineering; Development, planning and urban engineering; Energy; Corrosion protection of unbonded tendons; 8. PROTECTIVE MATERIAL. BASIC REQUIREMENTS FOR CORROSION PROTECTION 2 2 Taking into account the above research, the basic requirements for protecting unbonded tendons are as follows. (a) The main cause of corrosion is the penetration of moisture to the tendon, either .
Depending on the filler materials and strands, corrosion protection methods for post-tensioning tendon can be classified into: (i) grouted (bonded) tendon; (ii) unbonded tendon with flexible fillers; and (iii) extruded greased sheathed-strand (GSS) tendon with grouting as shown in Figure 4. adequate level of corrosion protection. Corrosion is an electrochemical process that degenerates the prestressing steel. The primary and secondary barrier against corrosion is the grease and tendon sheathing. The main objective of corrosion protection is to keep water away from the prestressing steel, especially when the. more, Maryland, following demolition conﬁrmed that no signiﬁcant corrosion had occurred on the unbonded tendons over the year service life (Suarez and Posten, ). The distinguishing characteristic of an unbonded tendon is that, by design, it does not form a bond along its length with the surrounding concrete. Our unbonded systems feature ” and ” diameter strands coated with a layer of specially formulated grease. The outer layer is seamless plastic extruded in one continuous operation to provide protection against corrosion. Each tendon is precisely coiled, cut, labeled, color-coded and delivered to the construction site.
Source: ACCELERATED LOW WATER CORROSION- A Matter of National Importance, 1 Jan (3–45) INTRODUCTORY NOTES Source: Design and management of post-tensioned concrete bridges, 1 Jan (9–58). Corrosion Inhibitor. The organic corrosion inhibitor shall be Visconorust or equivalent, (which surpasses the corrosion inhibitor standard in ACI Bldg. Code , Sec. , and the specification for “Unbonded Single Strand Tendons”, revised July by the Post-Tensioning Institute.) The corrosion inhibitor shall have a. The utilization of unbonded tendons is now standard practice for concrete structures. Because of their excellent performance record and their economical and versatile application, the total use of unbonded tendons increased from approximately tons in to over , tons of prestressing steel in , adding up to over 1 billion. PRESTRESSED UNBONDED TENDONS The evaluation of prestressed unbonded tendons for corrosion can be accomplished visually for short distances only by exposing the tendons, usually at the high or low points of the tendon’s drape. Although moisture is .