ASTM D4436-04

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D4436–04
Standard Test Method for
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Rock Bolt Long-Term Load Retention Test
This standard is issued under the fixed designation D 4436; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope* ging: Mechanical Caliper
1.1 The objective of this test method is to determine the
3. Terminology
time over which rock bolt tension decreases from the installed
3.1 See Terminology D 653 for general definitions.
value to a designated minimum value.
3.2 Definitions of Terms Specific to This Standard:
1.2 This test method is applicable to any anchor system
3.2.1 load—the total axial force on the rock bolt.
which is not fully encapsulated immediately upon installation,
3.2.2 design load—the load specified for the rock bolt
including mechanical, cement grout, resin (epoxy, polyester,
during the life of the project.
and the like) or other similar systems.
3.2.3 installation load—the load on the bolt immediately
1.3 The values stated in inch-pound units are to be regarded
after installation.
as the standard.
3.2.4 stand time—the time required for the bolt load to
1.4 All observed and calculated values shall conform to the
decrease from the installation load to the design load.
guidelines for significant digits and rounding established in
Practice D 6026.
4. Summary of Test Method
1.4.1 The method used to specify how data are collected,
4.1 A rock bolt is installed in the same manner and in the
calculated, or recorded in this standard is not directly related to
same material as its intended support use. The load on the bolt
theaccuracytowhichthedatacanbeappliedindesignorother
is monitored over a period of time, usually several weeks.
uses, or both. How one applies the results obtained using this
standard is beyond its scope.
5. Significance and Use
1.5 This standard does not purport to address all of the
5.1 Rock bolts are used for support in a variety of mining
safety concerns, if any, associated with its use. It is the
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and civil engineering situations. After a bolt is installed, the
responsibility of the user of this standard to establish appro-
load generally decreases over time due to deterioration of the
priate safety and health practices and determine the applica-
borehole wall, creep, and other factors. This process may be
bility of regulatory limitations prior to use.
arrested by fully encapsulating the bolt shortly after installa-
tion. This is generally done by pumping the bolt hole full of
2. Referenced Documents
cement grout, though synthetic resins may also be used. The
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2.1 ASTM Standards:
rate of load loss determines the interval during which the bolt
D 653 Terminology Relating to Soil, Rock and Contained
must be encapsulated during construction.
Fluids
5.2 The local characteristics of the rock, such as roughness
D 3740 Practice for Minimum Requirements for Agencies
of the borehole and induced fractures, are significant factors in
Engaged in the Testing and/or Inspection of Soil and Rock
the load loss characteristics of the bolt. To obtain realistic
as Used in Engineering Design and Construction
values, the test holes should be drilled using the same methods
D 4435 Method for Rock Bolt Anchor Pull Test
as those used for the construction boreholes.
D 6026 Practice for Using Significant Digits in Geotechni-
5.3 In establishing a testing program, the following factors
cal Data
should be considered:
D 6167 Guide for Conducting Borehole Geophysical Log-
5.3.1 Load retention tests should be conducted in all rock
types where construction bolts will be installed. If the rock is
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anisotropic, for example, bedded or schistose, the tests should
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
Rock and is the direct responsibility of Subcommittee D18.12 on Rock Mechanics.
Current edition approved July 1, 2004. Published July 2004. Originally approved
in 1984. Last previous edition approved in 1998 as D 4436 – 84 (1998).
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or For additional information see, “Suggested Method for Monitoring Rock Bolt
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Tension Using Load Cells,” Suggested Methods for Rock Bolt Testing, International
Standards volume information, refer to the standard’s Document Summary page on Society for Rock Mechanics Commission on Standardization of Laboratory and
the ASTM website. Field Tests, 1974.
*A Summary of Changes section appears at the end of this standard.
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