Experimental investigation on the short-term impact of temperature and moisture on reinforcement corrosion

• Reinforced specimens at different relative humidities and temperatures were studied.
• Passive reinforcement bars were not affected by variations in temperature and relative humidity.
• Active reinforcement showed a temperature dependent behaviour.
• Temperature dependency could be described by the Arrhenius equation. Moisture dependent activation energy was found.

In this study, reinforced concrete specimens with and without mixed-in chlorides were conditioned at different relative humidities and subsequently subjected to varying temperatures. Results of the study confirmed that neither temperature nor moisture content have a major impact on the corrosion state and rate of passively corroding reinforcement. For actively corroding reinforcement, a temperature and moisture dependent corrosion rate was observed. The temperature dependency could be described by the Arrhenius equation with moisture dependent activation energies of approximately 10 kJ/mol at 75% RH and 35–40 kJ/mol above 85% RH.