Pedro Castro-Borges

Reinforced Concrete Durability in Marine Environments DURACON Project: Long-Term Exposure

This paper presents the results, after a long-term evaluation in marine environments, from an Ibero-American project called “Effect of the environment on reinforcement durability” (DURACON). This p...

Concrete Carbonation in Ibero-American Countries DURACON Project: Six-Year Evaluation

Concrete carbonation data from 16 test sites in 9 countries (Bolivia, Chile, Colombia, Costa Rica, Mexico, Spain, Uruguay, Portugal, and Venezuela) were compared to identify concrete performance du...

Concrete Carbonation in Mexico and Spain: DURACON Project, Four Year Evaluation

This work is part of the DURACON Ibero-American project, which seeks to characterize concrete durability under environmental conditions, based on reinforced concrete sample exposure in at least two different atmospheres (marine and urban), for each of the 11 countries in the project. Specimens were exposed to the environmental conditions of 13 Mexican sites (8 urban and 5 marine atmospheres). Concrete specimens were 15 x 15 x 30 cm, with 6 rebars each, and three concrete covers (15, 20 and 30 cm). Two concrete mixtures were used with water/cement ratios of 0.45 and 0.65, respectively. Six reinforced and six plain concrete specimens were placed on each exposure site. Environmental data was collected on each exposure site, including rainfall, relative humidity, time of wetness, temperature, wind velocity, and carbon dioxide/chloride concentrations. Corrosion rates and potentials, as well as concrete resistivity were measured in the reinforced samples. Carbonation depths were measured on the plain ones. The present work focused on the measurements of environmental parameters during the first two years of exposure to analyze the potentiality and the probability of carbonation-induced corrosion, and the evaluation of the corrosion initiation period for the reinforcing steel on the 13 Mexican exposure sites.

The Use of Polarization Resistance to Evaluate the Environmental Impact on Reinforced Concrete Structures in the Iberoamerican Region

This work presents the three-year results of the project: Effect of the environment on reinforcement durability (DURACON), which is investigating the influence of the meteorochemical parameters of marine and coastal-marine environments on concrete durability performance, by measuring the electrochemical parameters (corrosion rate and corrosion potential) of the embedded reinforcing steel. To that effect, concrete specimens were exposed to the marine environments making a total of 21 test stations distributed among ten countries (Argentina, Bolivia, Chile, Colombia, Costa Rica, Mexico, Spain, Uruguay, Portugal and Venezuela). This paper presents the reinforcement electrochemical evaluation, which allows identifying its corrosion activation. The chloride ions concentration which induces the reinforcement corrosion is also presented, depending on the environment to which the concrete specimens were exposed.