Bundled reinforcing bars are normally required to have a minimum cover of at least the diameter of the bundle, except in permanent proximity to earth where the minimum will be:

• A. 3 inches
• B. 1 inch
• C. 2 inches
• D. 4 inches

Answer: (A)

Bundled reinforcing bars need concrete cover to protect the steel from moisture, chemicals in the environment, and cracking that could expose the bars. When bars are in a bundle, the usual rule is to have a cover at least equal to the bundle’s diameter to fully encase the group. But if the reinforcement is permanently in contact with the earth, that protection is increased to 3 inches to better guard against soil moisture and aggressive conditions over the life of the structure. So the minimum in permanent proximity to earth is 3 inches. The other options don’t fit because they would provide insufficient protection or exceed the specified requirement.