This article presents the study of the behaviour of reinforced concrete steels, used in constructions in Senegal, under the effect of corrosion. The study is carried out on locally manufactured steels from three (03) companies located in Senegal and on control bars imported from France. Type 1 (E1), Type 2 (E2) and Type 3 (E3) steels are locally manufactured and Type 4 (E4) steels come from France. For each type of steel, samples with diameters of 8 mm, 10 mm and 12 mm were used. Mass losses were evaluated after immersion of these samples in a corrosive solution. For each type of steel and for all the diameters studied, the corrosion rate that initiates cracking of the asphalt concrete was evaluated from the actual diameter of the bars and the thickness of the nominal coating. From the mass lost over time, correlations between duration and mass loss were established for all diameters of the different types of steel. These relationships made it possible to calculate the time required to reach the corrosion rate that initiates concrete cracking. The results indicate that 66.67% of the steels studied, of local manufacture, have a corrosion time that initiates cracking of concrete lower than that of the control bars imported from France. Type E1 steels with a diameter of 8 mm have a duration to reach the corrosion rate that causes cracking of concrete, equal to 49.71% of the duration of type E4 steels. These results indicate that the steels used in construction in Senegal do not have the same behaviour vis-à-vis corrosion.

The behavior of Fe500-3 iron was studied in the interstitial solution of mortar concrete, formulated from sand, cement, water, admixtures and in the presence of a clay (attapulgite) added as corrosion inhibitor. Indeed, in most cases in Senegal, mixing water and sand used in concrete formulations for buildings are subject to no treatment. The study solution was synthesized from these concretes at the 3rd, 7th and 28th day of wet cure. Fe500-3 iron corrosion tests in the interstitial concrete solution were carried out by monitoring the free corrosion potential, Tafel polarization curves and electrochemical impedance spectroscopy measurement. The protective power of attapulgite was also evaluated by electrochemical methods with different levels of inhibitor (0 to 20%). The measurements reveal a probable attack of Fe500-3 iron at the 3rd and 7th day of cure in the absence of inhibitor and the protective effect of the interstitial solution of the concretes without inhibitor at the 28th day of cure by the formation of a protective layer on the iron surface. The results also showed the corrosion inhibition effect of the clay on the 3rd and 7th day of cure by the formation of a protective film on the surface of the metal. The layer thickness increases with the content of the clay. A maximum average inhibitory efficiency of about 87.8% was obtained at the 7th day of cure at the 20% clay content.