MEASUREMENTS AND STUDYING CORROSION POTENTIAL OF REINFORCED CONCRETE SAMPLES PREPARED WITH AND WITHOUT A GREEN INHIBITOR AND IMMERSED IN 3.5% NaCl SOLUTION

In recent years the use of inhibitors in producing high performance concrete has increased significantly as a result of chloride and sulphate attacks. The effectiveness of an organic inhibitor extracted from a cheap organic waste of orange peel (so-called "green" inhibitor) was added to the fresh concrete. Two types of superplasticizers (Mapei Dynamon SR 31 and Oxydtron) were also used to reduce the water during concrete hardening. Then the concrete samples were immersed partially in 3.5% NaCl aqueous solutions for six months and every two weeks the corrosion potentials of the samples were regularly measured against a saturated calomel electrode. Results showed that the samples with Oxydtron had better ability to resist corrosion than the samples prepared with Mapei Dynamon SR 31, and samples with green inhibitor had less negative corrosion potentials (and even less with increasing concentration of inhibitor) than that of the reference sample (0% inhibitor).