Diagnosis and rehabilitation of real reinforced concrete structures in coastal areas

Abstract

A diagnosis and rehabilitation study of two reinforced concrete structures located in coastal areas in two different climates is presented. Building 1 was constructed in the north of Chile in 1949, at a distance of 600 m from the coastline, in a seismic zone. Cracks, steel corrosion, loosening of concrete cover and slab deformations have been identified. Building 2 was constructed in Habana City, Cuba, in 1973. It is located at <100 m from the shore. The structure of building 1 shows severe localised damage: loosening of reinforced cover and intense reinforcement bar corrosion due to high deposits of sea salts. High chloride and sulphate content in the concrete mass, low compressive strength in walls and slabs, high level of steel corrosion and zones with the existence of rust instead of steel were reported. A structural rehabilitation project to ensure an increase in service life is not possible. On the contrary, in case of building 2, a possible rehabilitation procedure is recommended. Elimination of chloride contaminated concrete and the use of special mortar is an option, and electrochemical chloride extraction and incorporation of sacrificial anodes is another. An important conclusion is made: the use of chloride and sulphate contaminated aggregates is more dangerous than the penetration of these two contaminants from the external environment for buildings constructed in coastal zones.