ABSTRACT
This chapter describes the mechanism of deterioration due to some of the processes concrete. Calcium hydroxide is produced during the hydration of Portland cement. This calcium hydroxide rests in the pores of concrete and it is this pore solution that provides alkalinity to the concrete. Carbonation can occur in two ways: surface carbonation and carbonation through the cracks. The behavior of carbon dioxide in a crack is different from the behavior of carbon dioxide in contact with a concrete surface exposed to the atmosphere. Corrosion of reinforced steel is an electrochemical process. Alkali ions present in Portland cement may react with some of the siliceous constituents that may be present in some of the aggregates, leading to expansion and cracking. Cavitation makes the concrete surface irregular and pitted in comparison to the erosion where solid particles in fluid erode the surface in a rather regular manner.
