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19 NACE INTERNATIONAL: VOL. 55, NO. 10 MATERIALS PERFORMANCE OCTOBER 2016 Information on corrosion control and prevention crete core sample is taken for chloride analysis, a f inal corrosion potential con- tour map is produced, and the lengths and widths of the concrete cracks are measured for all the specimens. Key parameter values to note at this point are combined macrocell currents after repair to the end of testing, chloride contents at the end of testing, and crack dimensions at the end of testing. The top layer of con- crete above the steel reinforcing bars is then removed from the specimens so the steel bar is visible (both front and back) and can be photographed in 6-in (152- mm) increments. Using tables in M-82 as a guideline, the surface corrosion of the steel in each slab is classif ied by percent- age of surface area corroded and degree of corrosion damage. According to the conference paper, the sacrif icial anodes are considered effective if the difference in the combined macrocell currents after repair is less than that in the control slabs, and crack- ing in the slabs with the anodes is reduced. Since considerable corrosion could occur before the repair treatment, there could be corrosion on the reinforc- ing bars in both the control and sacrif i- cial anode slabs. Providing a consistent test set-up so that different sacrif icial anodes in con- crete can be compared under the same test conditions is important for several reasons, Berke says. It provides a stan- dard method with a rigorous, unbiased test protocol that everyone can use to test planned concrete repairs with sacrif icial anodes. It also provides a method to test and compare anode materials to deter- mine if one material outperforms another. Additionally, the test protocol can be used to develop new sacrif icial anode materials for concrete repairs. Contact Neal S. Berke, Tourney Consulting Group—e-mail: NBerke@ TourneyConsulting.com. References 1 M-82, "Standard Protocol to Evaluate the Performance of Corrosion Mitigation Tech- nologies in Concrete Repairs" (Washington, DC: U.S. Bureau of Reclamation, 2014). 2 N.S. Berke, D. Little, B.E. Bucher, K.F. Von Fay, "Test Protocol to Evaluate the Effectiveness of Embedded Sacrificial Anodes in Rein- forced Concrete," CORROSION 2016 paper no. 7524 (Houston, TX: NACE International, 2016). 3 B. Elsener, "Macrocell Corrosion of Steel in Concrete—Implications for Corrosion Moni- toring," Cement and Concrete Composites 24, 1 (2002): pp. 65-72. —K.R. Larsen Applied Graphene Materials plc The Wilton Centre Redcar Cleveland TS10 4RF United Kingdom +44 (0)1642 438214 info@appliedgraphenematerials.com www.appliedgraphenematerials.com Create new barriers… • Significantly enhanced anti-corrosion and barrier properties • Very low loading additions • Other multi-functional performance gains with graphene • Dispersions developed and tailored to customers' requirements • Extensive in-house coatings and product integration expertise • Commercialised graphene production Tomorrow's anti-corrosion material. Today.