Effect of distance from sea on chloride aggressiveness in concrete structures in brazilian coastal site

Abstract

The distance of concrete structures from the sea is an important aspect when studying the deleterious effect of airborne salinity in marine environment zone. It permits to know how the durability of structures is affected by increasing the distance from the sea. This paper presents results of an experimental work on assessing the effect of the distance from sea on chloride aggressiveness, considering both the airborne salinity and chloride content in concrete specimens located at different distances from sea. This study has been carried out at Joao Pessoa, capital of the State of Paraiba, located in the northeast part of Brazil. The results indicated a drastic reduction of chloride deposition from marine aerosol, especially along the first 200 meters from the sea. Similar behavior was observed in the concrete specimens, even though the reduction has been less pronounced. Although more research is necessary, the differences in the rates of chloride decrease may be explained by different reasons, including the different chloride concentration in air and on concrete surface, the phenomena related to the skin effect and surface washing by rain.