Commercial Building Inspector B2Footings and FoundationsEasy
A commercial building inspector is reviewing the specifications for a new concrete foundation. The plans indicate the use of concrete with a specified compressive strength (f'c) of 2500 psi. What is the minimum curing period required for this concrete to achieve its design strength under normal conditions?
- A3 days
- B28 days
- C14 days
- D7 days
Show answer & explanationAnswer & explanation
Correct answer: D. 7 days
The IBC, referencing ACI 318, typically requires a minimum curing period of 7 days for concrete to achieve its specified design strength under normal conditions.
Why the other options are wrong
- A. 3 days is generally insufficient for concrete to achieve its design strength.
- B. 28 days is when concrete is typically tested for its full design compressive strength, but the minimum curing period for strength development is shorter.
- C. 14 days is a longer curing period, often used for more critical elements or in specific environmental conditions, but not the minimum for general foundations.
Concrete Curing Period
The minimum time concrete must be maintained at a favorable temperature and moisture content to ensure proper hydration and strength development.
- Essential for strength gain and durability.
- Typically 7 days for foundations under normal conditions.
- Prevents premature drying and cracking.
Memory trick: Wet Time Makes Strong Concrete