This work presents the preliminary results of the project: Effect of the environment on reinforcement durability (DURACON), which presents the physicomechanical and chemical characterization of the types of concrete prepared in the participating countries, as well as of the environment to which they are exposed. These results show the potentiality and probability of future reinforcement corrosion, depending on the type of mixture and the environment to which it is exposed.
To that effect, concrete specimens, with and without reinforcement, were prepared for electrochemical and physical/mechanical/chemical tests using the existing materials in each participating country, following premises that enabled the preparation of similar concrete samples. So two water/cement (w/c) ratios (0.45 and 0.65) were selected, where the concrete with w/c = 0.45 had to have a minimum cement content of 400 Kg/m3 and the one with w/c = 0.65 a compressive strength of 210 Kg/cm2. Portland I cement was used and the aggregate was silica type crushed with a 13-mm.
Maximum 1 Members of DURACON Project: Carmen Andrade/ International Coordinator Subprogram XV Corrosion, Environment Impact on Materials; Oladis T. de Rincón Internacional Coordinator DURACON; Mirta Barboza, Fabián Irassar/Argentina; Juan C. Montenegro/Bolivia; Maryangela G. de Lima, Paulo Helene/Brazil; Rosa Vera, Ana M. Carvajal/Chile; Ruby M. de Gutiérrez, Silvio Del Vasto/Colombia; Isabel MartÍnez, Marta Castellote/Spain; Andrés Torres, Pedro Castro/Mexico; Isabel DÍaz/Perú; Manuela Salta, Paula de Melo/Portugal; Gerardo RodrÍguez/Uruguay; Miguel Sánchez, Emilia A. de Partidas, Rafael Fernández/Venezuela.
Nominal Size (MNS) and quartz sand. The specimens were exposed to two types of environments, urban and marine (at least two stations for each country), making a total of 53 test stations distributed among twelve countries (Argentina, Bolivia, Brazil, Chile, Colombia, Cuba, Mexico, Spain, Uruguay, Paraguay, Portugal and Venezuela).The environment was evaluated using ISO Standard 9223 and the concrete was characterized by measuring compressive strength, modulus of elasticity, total and effective porosity, chloride permeability according to ASTM standards, as well as resistance to water absorption, using the Fagerlund method.
After a one-year exposure, the results of the corrosion potentiality and probability analysis of the reinforcement in the different test stations show that, for marine atmospheres, the most aggressive environment is at the Cabo Raso station in Portugal, inducing the greatest steel-corrosion probability and the least aggressive is the one at ValparaÍso in Chile. For carbonation, it was determined that the concrete prepared in Venezuela is the one that has the greatest probability of causing corrosion by carbonation of the reinforcement, with the station at Cali, Colombia being the one that would least induce corrosion of the reinforcement.
Originally, it was thought that the useful life of steel rod reinforced concrete as a building material was unlimited. However, premature deterioration caused by reinforcement corrosion is being reported in an increasing number of structures. In general, this corrosion is caused by the destructive attack of chloride ions penetrating either by diffusion from the outside or by incorporation into the concrete mix and/or carbonation of the concrete cover on the reinforcement.
Research on reinforcement corrosion is driven by the quest for a methodology that would provide a precise and correct answer to what causes corrosion. The diversity of procedures and products on the market provide a broad research field ?from theoretical foundations
