Método electroquímico para evaluar el efecto de la contaminación por CO2 sobre el deterioro de estructuras de concreto reforzado en la costa del Pacífico colombiano

Abstract

A electrochemical method to evaluate the carbonatation effect from CO2 atmospheric on degradation of concrete structures in Colombian pacific coast, mainly, on the penetration and the effective diffusion coefficient of chloride ion in concrete specimens made with Portland cement type I, with water/cement relationships: 0.4, 0.5 and 0.6. Samples with 28 days of curing were exposed to accelerated carbonation for two different fronts of carbonation: 5 mm (Face A) and 10 mm (Face B). The tests were carried out in an atmosphere of 25% CO2 and relative humidity between 55-65%. The penetration depth of the front was determined with phenolphthalein and carbonated and non carbonated samples, were characterized by XRD and SEM. Accelerated Chloride Migration Test (ACMT), Rapid Chlorides Penetration Test (RCPT) and penetration chlorides tests by immersion, in order to determine the income of the Cl- ion through the cement matrix and determine the effective diffusion coefficient of this type of concrete. Beside, colorimetric and potentiometric titration tests were carried out. There was a marked influence on the ability of chloride ion penetration through the cement matrix, in relation to passing current charge. It was corroborated by comparison of current charges calculated of the methods RCPT and ACMT, the influence of temperature on the diffusive capacity of the ions.