Abstract
The solution leaked from municipal solid wastes incineration（MSWI）fly ash and the roadbed solution scattered anti-freeze agent in the winter are chloride salt solution of high concentration. Also several kinds of salts are included. In this study, the influence of such highly-concentrated salts solution on the steel corrosion in concrete was investigated. In order to simulate MSWI fly ash, highly concentrated solution almost saturated was made of sodium chloride, potassium chloride and calcium chloride. The usefulness to the durability by the mix with fly ash was also compared. In the experiments, firstly the corrosion of rebar in concrete mixed with highly-concentrated salt solution was evaluated. Next the corrosion of rebar in concrete immersed in highly-concentrated salt solution was evaluated. Furthermore the influence of rebar in concrete with crack was evaluated. Based on the results obtained, it was verified whether a calculation model of the corrosion rate under chloride ion concentration less than 5.0kg/m3 established by JCI（Japan Concrete Institute）can be applied or not for highly concentrated salt solution composed of various kinds. As results, it could be cleared that the corrosion rate in a saturated salt solution was high, the influence of salt kinds on the corrosion was insignificant, the steel corrosion in concrete with coal fly ash was reduced in comparison with that of normal concrete, and the effect of chloride concentration on corrosion rate can be described by published equation regardless of the kinds of salt.
