General Contractor Practice Exam

What is the minimum acceptable concrete cover over reinforcement for concrete exposed to earth?

1. 2 inches

2. 3 inches

3. 4 inches

4. 5 inches

The correct answer is: 3 inches

The minimum acceptable concrete cover over reinforcement for concrete that is exposed to earth is typically set at a depth of 3 inches. This requirement is based on the need to protect the reinforcing steel from corrosion and physical damage, as soil conditions, moisture content, and the potential for chemicals in the ground can all contribute to the deterioration of the embedded steel over time. A cover of 3 inches provides sufficient protection to mitigate the effects of the surrounding environment, enhancing the durability and longevity of the concrete structure. This standard often aligns with guidelines provided in codes from organizations such as the American Concrete Institute (ACI) or other relevant building codes. While options that suggest a greater cover exist, they are generally associated with specific conditions or environments that may require additional protection, which is not necessary for typical earth-exposed concrete.