CHLORIDE PENETRATION INTO CONCRETE STRUCTURES IN MARINE ATMOSPHERE ZONE - INFLUENCE OF ENVIRONMENTAL CHARACTERISTICS

摘要

Chlorides from the sea are transported inland by the wind and represent an important source of degradation of concrete structures in marine atmosphere zone. This work studied the penetration of chlorides into concrete specimens exposed in marine atmosphere zone in Northeast of Brazil, at four different distances from the sea. Periodically, chloride profiles were obtained. At the same time, carbonation front advance was measured. Atmospheric salinity and climatic parameters were also systematically monitored. Results of four years of exposure time show that there is a strong decrease in chloride penetration into concrete, which is connected with the disposability of chlorides in atmosphere. However, this decrease does not follow a linear relation with the chlorides present in atmosphere. The influence of surrounding environment is more pronounced in surface concrete, which contributes to the skin effect and to stronger variations of surface chloride content.