Tecnotest AG 1 article published in JoVE Engineering Experimental Protocol to Determine the Chloride Threshold Value for Corrosion in Samples Taken from Reinforced Concrete Structures Ueli M. Angst1, Carolina Boschmann1, Matthias Wagner2, Bernhard Elsener1,3 1Institute for Building Materials, ETH Zurich, 2Tecnotest AG, 3Department of Chemical and Geological Science, University of Cagliari We propose a method to measure a parameter that is highly relevant for corrosion assessments or predictions of reinforced concrete structures, with the main advantage of permitting testing of samples from engineering structures. This ensures real conditions at the steel-concrete interface, which are crucial to avoid artifacts of laboratory-made samples.