Problem Solving Forum
April 16 - April 20, 2018
Do the balcony floor slabs on the high-rise seaside condo I’m working on in Florida really need cathodic protection?
Selected Answers
From
Zenith Czora of Durotech Industries, Inc. on
April 17, 2018:
Cathodic protection is designed to halt all the ac ...read more
Cathodic protection is designed to halt all the active corrosion of reinforced and pre-stressed concrete slabs and prevent newly installed reinforced concrete slabs from corrosion developing. Penetration of atmospheric contaminants such as CO2 or chlorides to reach the steel bars in the presence of oxygen and moisture will cause the reinforcing steel bars to corrode. Sooner or later, cracking and spalling occur as corrosion products build up around the rebars. In aggressive environments, particularly in coastal areas where chloride contaminants from wind-borne salt spray can be severe, it is therefore very important to provide sufficient cathodic protection to all the rebars of the concrete slab balconies and to other steel structures of the building.
From
Michael Halliwell of Thurber Engineering Ltd. on
April 16, 2018:
Balconies don't usually have a lot of redundancy t ...read more
Balconies don't usually have a lot of redundancy to them (especially cantilevered ones). If you have salt water contacting the concrete, you can have chloride-induced deterioration of the concrete itself as well as of the reinforcing steel. Weakened structure with time plus little redundancy plus loading can add up to a failure. I'd say the cathodic protection would be a good idea.