New Indicator Method for Determining Carbonization Zones in Concrete and Reinforced Concrete Structures

Abstract

The article considers a new indicator method for identifying zones of carbonization (neutralization) of concrete, which can be successfully applied in the practice of inspections of building structures made of concrete and reinforced concrete (at the field and laboratory stages of work). The aspects of the occurrence and course of the carbonization (neutralization) process are considered. The cases of its influence on the durability of concrete and reinforced concrete building structures of various objects (industrial, transport, civil, hydraulic, linear) are analyzed. Carbonization can lead to leaching of concrete under certain conditions. This is followed by damage of armature in reinforced concrete structures. The objects of the survey using the new method are considered. A comparison of the effectiveness of this method with the phenolphthalein test method is made. The disadvantage of the phenolphthalein test method (PPTM) is that it does not allow to understand the full picture of the pH distribution of concrete over layers, because the indicator has 1 working color transition interval. The difference of the new method consists in higher accuracy: the method allows to identify areas in which the corrosion process of concrete associated with the mass transfer of the target component during carbonization is just beginning or is fully proceeding. In addition, it helps to assess the condition of the protective layer of concrete at the current time. The new method is promising, because it allows assessing the condition of the examined reinforced concrete structures for their durability and degree of damage. The results of the study can be used in organizing the repair of concrete and reinforced concrete building structures.