Strength tests are normally:

Strength tests are normally:

• A. The average of 2 tests at a specified time, taken from the same pour.
• B. The maximum of three tests
• C. The average of two tests from different pours
• D. A single test at 28 days

Answer: (A)

Strength tests are normally calculated as the average of two cylinders tested at the specified age from the same pour. This approach reduces the impact of small variations in mixing, placement, curing, and handling, giving a more reliable representation of that particular batch’s strength. Testing two specimens from the same pour at the standard curing period (commonly 28 days) ensures the result reflects the actual concrete that was placed, rather than differences between batches or a single anomalous specimen. If you used a single test, a random defect could skew the result; if you used tests from different pours, you’d be averaging different batches; and taking the maximum of several tests would not provide a stable or representative measure of the pour’s strength.

Strength tests are normally calculated as the average of two cylinders tested at the specified age from the same pour. This approach reduces the impact of small variations in mixing, placement, curing, and handling, giving a more reliable representation of that particular batch’s strength. Testing two specimens from the same pour at the standard curing period (commonly 28 days) ensures the result reflects the actual concrete that was placed, rather than differences between batches or a single anomalous specimen. If you used a single test, a random defect could skew the result; if you used tests from different pours, you’d be averaging different batches; and taking the maximum of several tests would not provide a stable or representative measure of the pour’s strength.