ABSTRACT
It has been established that the depth of carbonation in concrete can be assessed visually by means of a spray test (5). In this test an indicator solution such as phenolpthalein is sprayed on to a freshly broken surface of concrete and those areas on the concrete which turn pink in colour indicate alkaline concrete with pH more than 9.5 or 10. It was found from the present study that the spray test was very useful in identifying areas where the pH of concrete has been lowered significantly by heavy chloride intrusion. The spray test was used as a rapid method for identifying the damaged areas and the depth of concrete cover that had been affected in these areas. Samples of concrete were taken both from damaged and undamaged areas and tested in laboratory. The soluble chloride was found to be as high as 28000 ppm, and pH value between 8 and 9.5 for the damaged concrete.
