EFFECT OF FLY ASHES ON THE CORROSION OF REINFORCING STEELS ABSTRACT
In order to determine the effect of fly ashes on the corrosion of reinforcing steel, two groups of concrete samples with defferent chloride ion concentrations were prepared. The former concrete block was prepared from normal Portland cement without any addition. The latter concrete block was prepared by adding 30 % fly ashes instead of concrete. Then, corrosion rates of reinforcing steels were measured . The corrosion rates were measured according to the galvanic current method between the former concrete block (prepared from the Portland cement) and the latter concrete block (with 30 % fly ashes and varied chloride ions). The corrosion potentials have been measured by applying ASTM C-876 method for 180 days. As a result of these experiments, it is found that, above the 1.5 kg/m3 chloride ions concentration, the reinforcing steels in the normal concrete has lost their passive form. But, when 30 % fly ashes were added to the concrete content, this chloride ions concentration limit (causing to reinforcing steel corrosion) has increased from 1.5 kg/m3 to 2.5 kg/m3.
Keywords: Corrosion, reinforcing steels, fly ashes.