Influence of Rapid Changes of Moisture Content in Concrete and Temperature on Corrosion Rate of Reinforcing Steel

Electrochemical tests on corrosion rate of reinforcement were performed on six concrete specimens reinforced with a single bar equipped with temperature and concrete moisture sensors. The specimens were kept in a climatic and corrosion chamber where ambient temperature was changing discretely in a temperature range of 7 °C ÷ 35 °C, and similarly humid conditions were changing in a range of 30% ÷ 90%. The tests were also conducted on specimens immersed in water at 7 °C and 35 °C. Temperature and moisture content in concrete at the bar surface were monitored throughout the tests. The objective of this work was to analyse the influence of rapid changes in climatic conditions maintained for a few-day cycles, on corrosion rate of reinforcement in concrete. The tests demonstrated that the current corrosion process models for concrete reinforcement which assumed an immediate response of corrosion rate to a change in climatic conditions, was correct only for temperature.