Evaluations of Sacrificial Anodes for Cathodic Protection of Reinforced Concrete Bridge Decks

Evaluations of Sacrificial Anodes for Cathodic Protection of Reinforced Concrete Bridge Decks
Author: David Whiting
Publisher:
Total Pages: 105
Release: 1995
Genre: Concrete bridges
ISBN:

Laboratory evaluations were carried out on a series of anode materials, including aluminum, magnesium, and zinc alloys. Anode/steel couples were placed in simulated concrete environments consisting of sealed containers filled with silica sand treated with a mixed alkali-chloride solution. Measurements of current flow, circuit resistance, potential, and depolarization were made over a period of 18 weeks. Based on results obtained, aluminum and zinc anodes were found to hold the most promise for use as galvanic anodes in reinforced concrete bridge decks. A series of reinforced concrete test slabs were produced for evaluation of the candidate materials. Normal-weight structural concrete, structural lightweight concrete, free-draining concrete, and free-draining latex-modified concrete overlays were placed over the anodes to serve as riding surfaces. Performance of the cathodic protection (CP) systems was evaluated using current flow and depolarization techniques.

Development of a New Sacrificial Cathodic Protection System for Steel Embedded in Concrete

Development of a New Sacrificial Cathodic Protection System for Steel Embedded in Concrete
Author: M. Funahashi
Publisher:
Total Pages: 178
Release: 1997
Genre: Concrete bridges
ISBN:

This is the interim report for a study to evaluate the use of sacrificial cathodic protection for reinforced and prestressed concrete bridge members. Cathodic protection (CP) using impressed current is an accepted and common method used to provide corrosion protection to steel in concrete. This study examined the performance of existing sacrificial alloys in different environments for sacrificial CP, and developed new sacrificial alloys for protecting steel in concrete. The study consisted of both laboratory and field tasks. The first task consisted of tests to identify suitable environments for sacrificial alloys. In the second task, two bridges with a zinc sacrificial anode in the Florida Keys were inspected and tested. Data on anode current output, anode and cathode potential, and anode and cathode depolarization were recorded.