Originated in the Nordic Countries Nord Test is a trademark of conformity assessment. The emphasis of Nord Test is to develop, promote and innovate Nordic test methods and pre-normative activity. SCOPE: This procedure is for determination of the chloride migration coefficient in concrete, mortar or cement-based repair materials from non-steady-state migration experiments. FIELD OF APPLICATION: The method is applicable to hardened specimens cast in the laboratory or drilled from field structures. The chloride migration coefficient determined by the method is a measure of the resistance of the tested material to chloride penetration. This non-steady-state migration coefficient cannot be directly compared with chloride diffusion coefficients obtained from the other test methods, such as the non-steady-state immersion test or the steady-state migration test. DEFINATONS Migration: The movement of ions under the action of an external electrical field. Diffusion: The movement of molecules or ions under a concentration gradient or, more strictly, chemical potential, from a high concentration zone to a low concentration zone. SAMPLING: The method requires cylindrical specimens with a diameter of 100 mm and a thickness of 50 mm, sliced from cast cylinders or drilled cores with a minimum length of 100 mm. Three specimens should be used in the test. TEST METHOD: Principles: An external electrical potential is applied axially across the specimen and forces the chloride ions outside to migrate into the specimen. After a certain test duration, the specimen is axially split and a silver nitrate solution is sprayed on to one of the freshly split sections. The chloride penetration depth can then be measured from the visible white silver chloride precipitation, after which the chloride migration coefficient can be calculated from this penetration depth. Apparatus: • Vacuum container: capable of containing at least three specimens. • Vacuum pump: capable of maintaining a pressure of less than 50 mbar (5 kPa) in the container. • Migration set-up: includes the following parts: – Silicone rubber sleeve: inner/outer diameter 100/ 115 mm, about 150 mm long. – Clamp: diameter range 105 - 115, 20 mm wide, stainless steel. – Catholyte reservoir: plastic box, 370 × 270 × 280 mm (length × width × height). – Plastic support. – Cathode: stainless steel plate about 0.5 mm thick. – Anode: stainless steel mesh or plate with holes about 0.5 mm thick. • Power supply: capable of supplying 0 - 60 V DC regulated voltage with an accuracy of ±0.1 V. • Ammeter: capable of displaying current to ±1 mA. • Thermometer or thermocouple with readout device capable of reading to ±1 °C. • Any suitable device for splitting the specimen. • Spray bottle. • Slide caliper with a precision of ±0.1 mm. • Ruler with a minimum scale of 1 mm. • Equipment for chloride analysis as required by the test method employed.