THE EFFECT OF CATHODIC POLARIZATION UPON BOND STRENGTH OF PRE-TENSIONED TENDON IN CONCRETE

Pull-out tests were performed upon concrete block specimens that contained either a centrally aligned seven wire pre-stressing ten or the central straight wire there from (no pre-tension) subseque to these having been subjected to various levels of cathodic polarization. The polarization utilized current densities of 50, or 2,500 mA/sq.m (4.6, 46, and 230 mA/sq.ft) (steel surface area basis) with charge density transfers extending to 13,994 A-h/sq.m (1300 A-h/sq.ft), where the latter is equivalent to 160 years of polarization at a current density of 10.8 mA/sq.m (1 mA/sq.ft). T ultimate bond strength occurred when the tendon or wire began to at the unloaded end (0.025 mm (0.001 in.) free end slip). In one of tendon pull-out specimens, ultimate bond strength decreased wi increasing total charge density transfer, whereas in a second set increased. Bond strength of wire specimens of both sets was approximately independent of total charge density transferred. In cases the data scatter was large relative to the absolute value o strength, thus making definition of any trend uncertain. Both friction from compressive stresses across the steel-concrete surf which developed from concrete shrinkage, and mechanical interlock associated with the spiral tendon, contributed to bond. The exten which concrete filled the re-entrant space between adjacent wires influenced bond in the case of the tendon specimens. It was concl that no practically significant bond loss results from cathodic polarization of pre-tensioned tendons in concrete. For the cover abstract see ITRD E117314.

• Corporate Authors:

  Federal Highway Administration

  Turner-Fairbank Highway Research Center, 6300 Georgetown Pike
  McLean, VA  United States  22101
• Authors:
  • DOHLEN, K
  • Hartt, W H
• Conference:
  • PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON CORROSION AND REHABILITATION OF REINFORCED CONCRETE STRUCTURES HELD 7-11 DECEMB 1998, ORLANDO, FLORIDA, USA
• Publication Date: 1999

Language

• English

Media Info

• Features: References;
• Pagination: 25 p.

Subject/Index Terms

• TRT Terms: Adhesion; Cables; Cathodes; Concrete; Conferences; Pretensioning; Steel; Strength of materials; Wire
• ITRD Terms: 5942: Adhesion; 4530: Cable; 4755: Concrete; 8525: Conference; 6951: Electrode; 4798: Pretensioning; 4542: Steel; 5544: Strength (mater); 4520: Wire
• Subject Areas: Data and Information Technology;

Filing Info

• Accession Number: 00943264
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, , USDOT
• Created Date: Jun 11 2004 12:00AM