Winter Leaves Behind Corrosion From Road Salt
A large part of the United States experienced an exceptionally harsh 2013 - 2014 winter. Chicago's severe experience forced the city to use three times the amount of road salts used in the previous winter. Road salts eventually seep into concrete and initiate corrosion of the underlying steel rebar. The high concentrations of road salts used by the city has caused a notable degradation of some bridges and concrete structures. Crews have been asked to knock off loose concrete from the bottom of bridges before it falls and causes injury. The corrosion decreased the service life of some structures as much as five to ten years.
The use of hot-dip galvanized rebar may have prevented the severe cracking and spalling now being observed in Chicago. While black steel or epoxy coated rebar may have been the least expensive solution for normal conditions in this area, extreme weather may have proven to be too much. Hot-dip galvanized rebar's corrosion products migrate through the concrete matrix; reducing pressure and avoiding the spalling and cracking seen with other systems. As a corrosion protection system, a hot-dip galvanized coating on rebar protects against extreme and unforeseen weather conditions.