The use of ground blast furnace slag, chrome slag and corn stem ash mixture as a coating against corrosion

The ground blast furnace slag (GBFC), chrome slag (CS) and corn stem ash (CSA), produced following a number of processes, were mixed with pitch in different proportions in order to increase adherence. Iron plates were then coated with this mixture. The coated and uncoated plates were left to corrode in a NaCl solution (35 g/L NaCl). The potential differences of the specimens were measured after they were kept in the solution for a month by electrodes. The potential difference for the uncoated iron plates (iron plates without GBFC, CS and CSA) was approximately 0.501 V. For those coated with pitch, this value was 0.363 V. On the other hand, the potential difference of the coated iron electrodes was determined to be 0 V revealing the absence of corrosion after the NaCl solution treatment and the suitability for the use of the ground blast furnace slag, chrome slag and corn stem ash as coating materials.

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► Ground blast furnace slag (GBFC), chrome slag (CS) and corn stem ash (CSA) are examined for corrosion resistant coat.
► Cases tested are bare iron, pitch coated iron and iron coated with foregoing stuff.
► Potential differences were 0.501, 0.363 and 0 V, repectively, the last meaning no corrosion.
► The corrosion rate decreased with the increase of reactive SiO2 in the coat material.
► GBFC, CS and CSA are advisable coating materials against corrosion of rebars in concrete.