A survey is reported of the electric potential and chloride content of 14 sections of continuously reinforced concrete pavement (CRCP) on interstate routes in Iowa. The projects were selected on the basis of age and the source of the aggregate content in the concrete. Five test locations for each project were selected; all locations were to the right of the midpoint of the righthand lane. Details of core drilling electrical potential measurement are briefly described. Concrete samples for chloride determination were obtained at 2 points on cracks and 2 points between cracks. The average electrical potential readings, the chloride content, and the crack spacing are summarized in tables. The study indicates that electrical potential greater than -0.35 volt provides a high level of assurance that corrosion is active. A chloride content of one or more pounds per cubic yard of concrete supplies the environment for corrosion but does not mean that active corrosion is occurring. The results of the Iowa survey do not indicate serious, wide-spread corrosion of the longitudinal reinforcement in CRCP. The results suggest that corrosion could be a matter of concern in the future. It is also true that while a potential of -0.35 volt indicates a high probability of corrosion in a bridge deck, it has not been proven that this same value holds true for CRCP.

Media Info

  • Features: Figures; Tables;
  • Pagination: 21 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00135036
  • Record Type: Publication
  • Created Date: Aug 11 1976 12:00AM