General Contractor Practice Exam

How much concrete coverage is necessary for 5/8 inch rebar used on floors?

1. 1/2 inch

2. 3/4 inch

3. 1 inch

4. 1 1/2 inches

The correct answer is: 3/4 inch

For 5/8 inch rebar used in floor applications, a concrete coverage of 3/4 inch is specified to ensure adequate bonding, protection from corrosion, and to maintain structural integrity. This coverage helps to provide a sufficient layer of concrete over the rebar, which prevents moisture from reaching the steel and reduces the risk of corrosion over time. The 3/4 inch coverage also fulfills other design requirements, such as spacing for thermal expansion and contraction, allowing for proper stress distribution throughout the floor. Maintaining the right coverage is crucial for the long-term durability and strength of the concrete structure, ensuring that it meets necessary safety standards and performs well under load. The other values do not provide the optimal balance between protection and structural performance; for example, 1/2 inch may not offer enough coverage to prevent corrosion, and 1 inch or 1 1/2 inches may unnecessarily increase the volume and cost of concrete.