Bridges and buildings require periodic tests to analyse their integrity. Most of the bridges are subjected to adverse weather conditions which compromise their load carrying capacity as time goes. Some of the tests done on these bridges are; 1. Carbonation test- this is a test that is used to estimate the effective good cover of concrete. The test is usually done using the phenolphthalein indicator which turns it's colour to pink in regions where carbonation has not occured due to the alkaline nature of cement.