This is a partial destructive test that is used to determine the Concrete durability of reinforced concrete structures that have been exposed to certain environmental conditions, for example in carbonating environments. Carbonation-induced corrosion affects all structures where the moisture saturation level of the capillaries is suitable for supporting both CO2 ingress and steel oxidation. These conditions are typically found in the externally exposed elements of structures and buildings which may be exposed or sheltered from rain, which accounts for around 2/3 of all structural concrete used. The service life of most reinforced concrete building structures is, therefore, normally governed by cover carbonation and subsequent reinforcement corrosion (Hobbs et al, 1998).
For purposes of this test, concrete core samples will be extracted for the reinforced concrete elements then a chemical agent - Phenolphthalein indicator is applied on the cored samples so as to determine the carbonation depth.