Active Standard ASTM D5873 | Developed by Subcommittee: D18.12
Book of Standards Volume: 04.08
Historical (view previous versions of standard)
Significance and Use
4.1 The rebound hardness method provides a means for rapid classification of the hardness of rock during site characterization for engineering, design, and construction purposes, geotechnical mapping of large underground openings in rock, see Guide D4879, or reporting the physical description of rock core, see Practice D4543.
4.2 The rebound hardness number, HR, can serve in a variety of engineering applications that require characterization of rock material. These applications include, for examples, the prediction of penetration rates for tunnel boring machines, determination of rock quality for construction purposes, grouping of test specimens, and prediction of hydraulic erodibility of rock.
1.1 This test method covers the testing apparatus, sampling, test specimen preparation, and testing procedures for determining the rebound hardness number of rock material using a spring-driven steel hammer, referred to variously as a rebound hammer, impact test hammer, or concrete test hammer.
1.2 This test method is best suited for rock material with uniaxial compressive strengths ranging between approximately 1 and 100 MPa. Test Method D7012 provides more information on compressive strength of rock.
1.4 Rebound hammers are available from their original manufacturers in several different energy ranges. For a given plunger tip diameter and radius of curvature, the impact energy of the rebound hammer determines its range of applicability. Accordingly, this limitation should be kept in mind when selecting a hammer type. Earlier recommendations for rock mechanics applications were only for hammers with an impact energy of 0.735 Nm, especially on smaller core samples and weaker rocks (see also Brown 19812). Any rebound hammer may be used, however, this test method applies only to hammers with an impact energy not to exceed 0.735 Nm. Hammers with energies above 0.735 Nm tend to break the rock and are not recommended.
1.5 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.
1.6 This test method is used to test rock. For concrete testing, see Test Method C805/C805M.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
C805 Test Method for Rebound Number of Hardened Concrete
D420 Guide to Site Characterization for Engineering Design and Construction Purposes
D653 Terminology Relating to Soil, Rock, and Contained Fluids
D3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
D4543 Practices for Preparing Rock Core as Cylindrical Test Specimens and Verifying Conformance to Dimensional and Shape Tolerances
D4879 Guide for Geotechnical Mapping of Large Underground Openings in Rock
D7012 Test Method for Compressive Strength and Elastic Moduli of Intact Rock Core Specimens under Varying States of Stress and Temperatures
ISRM StandardsSuggested Method for Quantitative Description of Discontinuities in Rock Masses
ICS Number Code 13.080.20 (Physical properties of soil)