Behaviour of Surface Chloride Concentration in Concretes Subjected to Field Exposure in Marine Atmosphere Zone

Abstract

Surface chloride concentration (Cs) is one of the parameters that feed models used to simulate chloride ingress into concrete. Therefore, understanding its behaviour over time is important for a more accurate forecasting. This work is part of a larger researcher project that aims to analyse the transport of chlorides into concrete in marine atmosphere zone based on long-term field exposures. The present paper focuses on the behaviour of Cs along 12.5 years. Prismatic concrete specimens with three different mixtures were exposed at places located at four different distances from the sea. Climatic variables and chloride deposition on the wet candle were parameters used to characterise the environment. Periodically, samples from concrete surface were extracted from the specimens and chemically analysed. Results show that Cs increases along the years and suggests a tendency of stabilisation over time, although this level could not be reached in the present exposure period. The relationship between Cs and chloride deposition rate on the wet candle was analysed and it was observed that the function ���� = ��0 + ������. (������)�� is the one that best fits to experimental data.

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