Are there any tests that may be made directly on the structure to determine if the concrete has developed adequate strength without risk of overloading or causing damage to the structure?

Q. Are there any tests that may be made directly on the structure to determine if the concrete has developed adequate strength without risk of overloading or causing damage to the structure?

A. Yes. There are several methods to estimate the in-place strength of concrete in existing construction. The methods include rebound hammer, penetration resistance, pullout, pull-off, and ultrasonic pulse velocity (ACI 228.1R). Generally, these methods require a strength relationship, which is usually established for large projects. The most accurate method is to remove and test cores in accordance with ASTM C42.

References: SP-1(02); ACI 228.1R-19; SP-168; ASTM C42

Topics in Concrete: Nondestructive Testing; Testing of Concrete