Title: Chloride Induced Corrosion of Steel Bars Embedded in Ecocement-Blast-Furnace Slag Mortars
Author(s): K. 0. Ampadu, Kazuyuki Torii, and Takashi Kubota
Publication: Symposium Paper
Appears on pages(s): 681-698
Keywords: blast-furnace slag; chloride ions; differential scanning
calorimetry; ecocement; half cell potential; linear polarization resist-ance;
steel corrosion; x-ray diffraction
Synopsis: Ecocement is a new type of hydraulic cement made from incinerator ashes. In this study, the effect of blast-furnace on the corrosive behaviour of steel bars embedded in mortars made from two types of ecocement; rapid hardening type with high chloride content, and NPC type with low chloride content, was investigated. Cement-slag mortars were prepared with both types of cement. The mortar specimens, with mild steel and stainless steel bars embedded, were placed in an environmental chamber under severe saline conditions. The corrosion of the mild steel bars was monitored by electro-chemical measurements. Chloride concentration profiles in cylindrical mortar specimens were also measured after the exposure period. The results of the various tests clearly indicate the beneficial effect of slag on the time of corrosion initiation and the degree of corrosion of the steel bars.