Chloride contamination of reinforced concrete structures, usually caused by deicing salts or marine exposure, is recognized as a major contributor to structural deterioration by causing reinforcing steel corrosion. To assess the future life and to determine the remedial requirements of a chloride-contaminated concrete structure, we need a comprehensive knowledge of the chloride ion content and the extent of corrosion activity. A quick, simple test has been developed to make chloride analyses without a chemistry laboratory setup.
DETAILS OF TEST METHOD
Dry powder samples can be obtained conveniently using a percussion drill. Chlorides are extracted from the powder by immersion of 10 grams of powder in 50 milliliters of extraction solution, immediately shaking vigorously for 1 minute, and then taking a reading. The chloride electrode is inserted into the solution, and the chloride content is displayed directly on a precalibrated digital readout meter.
HOW TO CHECK BY TITRATION
If it is thought necessary to check the results by the titration method, there are two ways to proceed. First, a large enough powder sample can be taken by drilling multiple holes in the same area and blending the powders together. Then divide the powder and have it analyzed by both methods. If there is no extra powder available, an acid extraction and titration may be done directly on the already extracted sample.