Numerical evaluation of the capacity of galvanic anode systems for patch repair of reinforced concrete structures

Materials and Corrosion, vol. 71, pp. 726–737

Abstract

Abstract Cathodic protection (CP) is an electrochemical repair or corrosion prevention technique for steel structures exposed to a corrosive environment. For reinforced concrete (RC) usually impressed current CP is used, due to the comparably high resistivity of the concrete, serving as electrolyte. Nevertheless, the market provides a wide range of galvanic anode systems for RC structures. Their most common use is the application within the framework of partial concrete replacement due to chloride‐induced corrosion. This patch repair is often accompanied by the so‐called anode ring effect, causing accelerated corrosion of the rebar in the substrate concrete in the vicinity of repair patches. This is caused by the cathodic capabilities of the repassivated rebar. Galvanic anodes are reported to prevent this effect. In this paper, a numerical model is proposed, which is capable of determining the effectiveness of the method dependent on, for example, the type and quantity of anodes, rebar content, and geometry or climatic conditions. The method is presented for a specific set of input parameters and the applicability is discussed against the background of different protection criteria.

Authors 2

1. Christian Helm corresponding Aachen Institute of Building Materials Research

   RWTH Aachen University

   Affiliation as printed

   Institute of Building Materials Research RWTH Aachen University Aachen Germany

   Institute of Building Materials Research, RWTH Aachen University, Aachen, Germany

2. Michael Raupach Aachen Institute of Building Materials Research

   RWTH Aachen University

   Affiliation as printed

   Institute of Building Materials Research RWTH Aachen University Aachen Germany

   Institute of Building Materials Research, RWTH Aachen University, Aachen, Germany