Construction Materials, Vol. 4, Pages 194-215: Study of Concrete Reinforcement with the Addition of Pozzolans against the Penetration of Chlorides Using Electrochemical Impedance Spectroscopy

Construction Materials, Vol. 4, Pages 194-215: Study of Concrete Reinforcement with the Addition of Pozzolans against the Penetration of Chlorides Using Electrochemical Impedance Spectroscopy

Construction Materials doi: 10.3390/constrmater4010011

Authors: Anilé Ossorio Domínguez Romildo Dias Toledo Filho José Antônio da Cunha Ponciano Gomes Ralph dos Santos Silva Eduardo Alencar de Souza Adriana Barbosa da Silva

The present work analyzes the behavior in terms of corrosion resistance of three reinforced concrete formulations over a period of 1 year. The samples were subject to a monitoring methodology using the Electrochemical Impedance Spectroscopy (EIE) technique, working only with the real component over time. Three mixtures were used, one conventional without pozzolanic addition (REF) and two others with pozzolanic additions, rice husk ash (RHA) and metakaolin (MK). Prototypes were created and exposed to the action of a 165 g/L NaCl sodium chloride solution. The characterization of the materials was carried out by determining the chloride diffusion profile (ASTM 1556), analyzing images using tomography and with the support of analytical techniques such as X-ray fluorescence and X-ray diffraction. The monitoring methodology using EIE demonstrated the positive effect of the insertion of pozzolans, rice husk ash (RHA) and metakaolin (MK) in delaying the process of chloride diffusion in the concrete, resulting in greater resistance to corrosion. The EIE also showed that the active mineral addition in concrete, resulting in aluminum-silicic composition (MK), had a predominant protective effect on the steel/concrete interface against the attack of chloride ions.