ASTM A981/A981M-11

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: A981/A981M − 11
StandardTest Method for
Evaluating Bond Strength for 0.600-in. [15.24-mm] Diameter
Steel Prestressing Strand, Grade 270 [1860], Uncoated,
1
Used in Prestressed Ground Anchors
This standard is issued under the fixed designationA981/A981M; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope Testing of Hydraulic Cements and Concretes
C1019 Test Method for Sampling and Testing Grout
1.1 This test method describes procedures to establish the
E4 Practices for Force Verification of Testing Machines
relativebondstrengthof0.600-in.[15.24-mm]diameter,Grade
270 [1860] steel prestressing strand in cement grout as used in
3. Terminology
prestressed ground anchors for the purpose of evaluating the
3.1 Definitions of Terms Specific to This Standard:
effects of manufacturing practices on bond strength.
3.1.1 bond strength—maximum measured load in a pull test
1.2 Thebondstrengthvaluesobtainedarenotintendedtobe
on a 0.600-in. [15.24-mm] diameter steel prestressing strand
used to design the bond length of ground anchors that depend
embedded in cement grout.
on field conditions.
3.1.2 bonded length—the length of the test strand that is in
1.3 Thistestmethodisnotintendedtobeusedasabondtest
contact with the cement grout.
for prestressed concrete applications.
4. Apparatus
1.4 The values stated in either inch-pound or SI units are to
be regarded as standard.Within the text, the SI units are shown
4.1 Equipment—A suitable tensile testing machine or load
in brackets. The values stated in each system may not be exact
frame shall be used. The loading system shall be calibrated in
equivalents;therefore,eachsystemshallbeusedindependently
accordance with Practices E4. The test system shall have
of the other. Combining values from the two systems may
sufficient capacity to prevent yielding of its various compo-
result in non-conformance with the standard.
nents and shall ensure that the applied tensile load remains
1.5 This standard does not purport to address all of the parallel to the axis of the steel prestressing strand during
safety concerns, if any, associated with its use. It is the testing.
responsibility of the user of this standard to establish appro-
4.2 Strand Displacement Measurements—Displacements of
priate safety and health practices and determine the applica-
the free end of the steel prestressing strand shall be measured
bility of regulatory limitations prior to use.
with respect to the loaded surface of the test specimen using
suitable measurement devices. Dial gages having the smallest
2. Referenced Documents
division of not more than 0.001 in. [25 µm] or linear variable
2
2.1 ASTM Standards:
differential transformers (LVDTs) with equal or superior accu-
A416/A416M Specification for Steel Strand, Uncoated
racy are examples of satisfactory devices.
Seven-Wire for Prestressed Concrete
C150 Specification for Portland Cement 5. Strand Bond Test Specimen
C511 Specification for Mixing Rooms, Moist Cabinets,
5.1 Steel Prestressing Strand—Strand shall be 0.600-in.
Moist Rooms, and Water Storage Tanks Used in the
[15.24-mm] diameter, Grade 270 [1860] and comply with
Specification A416/A416M and shall be cut from standard
production coils prior to packaging. The surface of the test
1
This test method is under the jurisdiction of ASTM Committee A01 on Steel,
samples shall not be wiped or cleaned in order to preserve their
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
A01.05 on Steel Reinforcement.
original condition. Minimum recommended sample length is
Current edition approved April 1, 2011. Published May 2011. Originally
30 in. [750 mm].
approved in 1997. Last previous edition approved in 2007 as A981 – 97 (2007).
DOI: 10.1520/A0981_A098M-11.
5.2 Test Specimen Fabrication—The test specimen shall
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
consist of the steel prestressing strand embedded in cement
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
grout and centered inside a steel pipe, 5-in. [125-mm] O.D.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. with a 0.125-in. [3-mm] thick wall, 18-in. [450-mm] long with
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
A981/A981M − 11
a 6 by 6 by 0.25 in. [150 by 150 by 6 mm] base plate welded shown in Fig. 1. A sealing agent shall be applied around the
to one end of the steel pipe, or o
...