Corrosion Propagation of Rebar Embedded in High Performance Concrete

The FDOT has been using supplementary cementitious materials while constructing steel reinforced concrete marine bridge structures for over 3 decades. Previous findings indicated that such additions in concrete mix makes the concrete more durable. To better understand corrosion propagation of rebar in high performance concrete: mature concrete samples that were made (2008/2009) with Portland cement, a binary mix, a ternary mix and recently prepared (April 2016 with 50% OPC + 50% slag and 80% OPC + 20% Fly ash) concrete samples were considered. None of these concretes had any admixed chloride to start with. An accelerated chloride transport process was used to drive chloride ions into the concrete so that chlorides reach and exceed thechloride threshold at the rebar surface and initiate corrosion. Electrochemical measurements were taken at regular intervals (during and after the electro-migration process) to observe the corrosion propagation in each sample.