Influence of temperature on electrochemical remedial measures and complex deterioration due to chloride attack and ASR

• Complex deterioration of chloride attack and ASR was affected by temperature.
• Rise in electrolyte temperature from 30 to 40 °C improved penetration of lithium.
• 40 °C electrolyte of LiNO3 was most effective to suppress expansion due to ASR.

Complex deterioration mechanism due to both chloride attack and ASR are greatly affected by environmental temperature. In this study, the influence of environmental temperature on concrete expansion and steel corrosion was experimentally investigated. As a result, some protection effect against steel corrosion was found in the cases of storage at 30 °C or 40 °C, although ASR expansion was promoted. This would be caused by the formation of alkali silica gel around the steel. As a remedial measure against such a complex deterioration, electrochemical penetration of lithium from the electrolyte solution was also investigated. It was clarified that electrolyte temperature greatly affected the extent of lithium penetration and the treatment at 40 °C remarkably accelerated lithium penetration into concrete compared with the case of 30 °C. Regarding the kind of lithium salt, LiNO3 solution was most effective among a number of different kinds of lithium salt.