The results of a study on the use of cathodic protection on prestressed and post-tensioned concrete bridge members are summarized. Previous laboratory tests to evaluate hydrogen embrittlement of high strength steel embedded in concrete have proven that cathodic protection will generate hydrogen on high-strength steel in concrete if the potential is more negative than the thermodynamic hydrogen evolution potential. The hydrogen generated will enter the steel and cause a loss in ductility that will adversely affect the steel's performance if a notch is present. Full-scale beams were constructed to further study those phenomena. Four pretensioned beams were constructed. In addition, two post-tensioned slabs were constructed to evaluate cathodic protection of anchorages and tendons encased in metal or plastic conduits. Cathodic protection currents were supplied by IR drop-free potential controlled rectifiers. Good potential control at control points was achieved by using externally mounted silver-silver chloride reference electrodes and a conductive gel bridge. However, inconsistent potential control occurred at locations other than at the control points. Later in the study, constant current power supplies were used on two of the beams. Hydrogen entering the steel as the result of corrosion appears to have masked the presence of hydrogen that might have been produced by cathodic protection. The analysis also revealed that there was corrosion of some pretensioned wires at crossings with interior steel reinforcing bars due to interference (stray current) caused by cathodic protection application. Analysis of the post-tensioned slabs indicated little effect of cathodic protection on tendons inside plastic or metal ducts from the application of cathodic protection. Beneficial effects were noted on anchor points where mortar was in contact with the metal.


    Access

    Download

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Cathodic Protection of Prestressed Bridge Members—Full-Scale Testing


    Additional title:

    Transportation Research Record: Journal of the Transportation Research Board


    Contributors:


    Publication date :

    1996-01-01




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English



    Cathodic Protection of Prestressed Bridge Members—Full-Scale Testing

    Funahashi, Miki / Young, Walter | Transportation Research Record | 1996



    Cathodic Protection for Protecting Prestressed Concrete

    Katawaki, K. / Sakomoto, H. / Ishikawa, A. et al. | British Library Conference Proceedings | 1993


    Cathodic Bridge Deck Protection

    L. Smith | NTIS | 1990


    Localized cathodic protection of simulated prestressed concrete pilings in seawater

    Chaix, O. / Hartt, W.H. / Kessler, R. et al. | Tema Archive | 1995