ASTM C805/C805M − 13a Standard Test Method for Rebound Number of Hardened Concrete

ASTM C805/C805M − 13a Standard Test Method for Rebound Number of Hardened Concrete

Scope*
1.1 This test method covers the determination of a rebound number of hardened concrete using a spring-driven steel hammer.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard.

The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other.

Combining values from the two systems may result in non-conformance with the standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use.

It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

ASTM C805/C805M − 13a Standard Test Method for Rebound Number of Hardened Concrete

Significance and Use
5.1 This test method is applicable to assess the in-place uniformity of concrete, to delineate variations in concrete quality throughout a structure, and to estimate in-place strength if a correlation is developed in accordance with 5.4.
5.2 For a given concrete mixture, the rebound number is affected by factors such as moisture content of the test surface, the type of form material or type of finishing used in construction of the surface to be tested, vertical distance from the bottom of a concrete placement, and the depth of carbonation.

These factors need to be considered in interpreting rebound numbers.