ASTM C805
Full Name
ASTM C805 – Standard Test Method for Rebound Number of Hardened Concrete
Scope
ASTM C805 describes a non-destructive test method to determine the rebound number of hardened concrete. This is done using a spring-loaded steel hammer. The hammer impacts a steel plunger in contact with the concrete surface, and the distance the hammer rebounds is measured. This rebound distance is correlated to the hardness of the concrete, which can then be used to estimate its compressive strength.
Key aspects covered by ASTM C805:
- Purpose: the main purpose is to assess the uniformity of concrete in a structure and to delineate areas of poor quality or deteriorated concrete.
- Applicability: this test method is suitable for various types of concrete, both in the laboratory and in the field.
- Limitations: this method should not be used as the sole basis for acceptance or rejection of concrete. It’s also not suitable for very soft or very hard concretes, and it can be influenced by several factors like surface moisture, smoothness, carbonation, and type of coarse aggregate.
Important considerations:
- This test method only provides an indirect estimate of compressive strength. Proper correlation between rebound number and compressive strength should be established for the specific concrete being tested.
- The test surface should be smooth, clean, and dry.
- Multiple readings should be taken at different locations on the concrete surface to get a representative value.
ASTM C805 Accredited Laboratory
Applied Testing & Geosciences, LLC is accredited for performing tests using the ASTM C805 standard.
Contact us today to learn more about our testing capabilities and how we can support your business.
Resources
Keywords
rebound hammer; rebound number; hardened concrete; compressive strength; nondestructive testing; surface hardness; correlation; calibration