25 years Composite Microcapillary Matrix

The concept of the micro-capillary matrix is based on the formation of a micro-capillary matrix by impregnation of the concrete adjacent to the anode/concrete interface with an alumo-silicate binder that forms acid-resistant zeolite-like structures that act as a sponge that pulls the alkaline concrete pore solution towards the anode/concrete interface neutralizing the anodically produced acid. Evaluation of laboratory scale probes by ESEM/RDX revealed the formation of zeolite-like structures in the concrete pore space; references are cited in the paper. Electrochemical evaluation proved that long-term current densities of 35 mA/m2 and short-term current densities of > 100 mA/m2 are supported without loss of performance. Since 1998, the CAS Composite Anode has been applied in 96 projects protecting the steel in concrete in parking decks, road and highway bridges, seaside apartment buildings, concrete basins of swimming pools, concrete retaining walls, and marine civil structures.

Presented at ICCRRR 2024:

"CAS Composite Anode – 25 years of experience with the concept of microcapillary
matrix applied to carbon-based conductive coatings for the CP of steel
in concrete,
Part 1: Physico-chemical and electrochemical evaluation
Part II: selected field experiences"

W. Schwarz¹⁾, N. Katsumi¹⁾, A. van den Hondel²⁾, H. Esteves³⁾

¹CAS Composite Anode Systems GmbH, Vienna, Austria
²Cathodic Protection Supplies, Rotterdam, Netherlands
³Catodica, Mönchengladbach, Germany

 25 years Composite Microcapillary Matrix