Which statement about concrete cover is true?

Which statement about concrete cover is true?

• A. It is measured from the concrete surface to the outermost surface of the steel.
• B. It is measured from the center of the steel to the outer surface.
• C. It is measured from the top of the concrete to the rebar.
• D. It is not important.

Answer: (A)

Concrete cover is defined as the distance from the outer surface of the concrete to the outer surface of the reinforcing steel. This measurement ensures the steel is protected from moisture, chemicals, and fire and that there is proper bonding with the surrounding concrete. The statement that best matches this definition is the one that measures from the concrete surface to the outer surface of the rebar, not to its center. Measuring to the center would understate the actual cover, and measuring only from the top surface ignores the requirement around the entire circumference of the bar. It’s also not unimportant; cover is critical for durability and structural performance, and codes specify minimum cover values based on exposure and member type.

Concrete cover is defined as the distance from the outer surface of the concrete to the outer surface of the reinforcing steel. This measurement ensures the steel is protected from moisture, chemicals, and fire and that there is proper bonding with the surrounding concrete. The statement that best matches this definition is the one that measures from the concrete surface to the outer surface of the rebar, not to its center. Measuring to the center would understate the actual cover, and measuring only from the top surface ignores the requirement around the entire circumference of the bar. It’s also not unimportant; cover is critical for durability and structural performance, and codes specify minimum cover values based on exposure and member type.