Abstract
Changes in temperature due to global warming could increase the risk of corrosion damage to critical reinforced concrete (RC) infrastructure and impose challenges to the corrosion protection of bridges exposed to extensive amounts of de-icing salt in the winter. The chloride threshold limit (CTL) of a steel reinforcing bar (rebar) indicates its corrosion resistance to chlorides. CTL is one of the governing parameters determining the time to corrosion initiation. This study presents an experimental investigation of the temperature dependency of CTL for six types of rebar, including four grades of stainless steel subjected to pitting corrosion characterized by the potentiodynamic polarization method. The temperature was an important influencing factor on the CTL of alloys. As expected, the corrosion resistance of the rebars (i.e., CTL) decreased with higher temperatures.
Additionally, the temperature dependence of the CTL was found to vary significantly among the six alloys. This study suggests that the temperature variation in the atmosphere can affect the corrosion resistance of rebar materials used in concrete, hence, changing the service life of these structures. The effect of temperature on CTL of reinforcing steel materials should be further understood and considered when selecting these alloys for more extended service design of concrete structures.
