ASTM A944-99

Standard Test Method for Comparing Bond Strength of Steel Reinforcing Bars to Concrete Using Beam-End Specimens

SCOPE
1.1 This test method describes procedures to establish the relative bond strength of steel reinforcing bars in concrete.  
1.2 This test method is intended to determine the effects of surface preparation or condition (such as bar coatings) on the bond strength of deformed steel reinforcing bars (of sizes ranging from No. 10 to No. 35 [No. 3 to No. 11]) to concrete.  
1.3 The values stated in SI units are to be regarded as the standard. The values given in brackets are for information only.  
1.4 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.

General Information

• Status: Historical
• Publication Date: 09-Nov-1999
• ICS: 91.080.10 - Metal structures
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.05 - Steel Reinforcement

Relations

• Replaced By: ASTM A944-99(2004) - Standard Test Method for Comparing Bond Strength of Steel Reinforcing Bars to Concrete Using Beam-End Specimens
• Effective Date: 10-Nov-1999
• Referred By: ASTM A775/A775M-22 - Standard Specification for Epoxy-Coated Steel Reinforcing Bars
• Effective Date: 10-Nov-1999
• Referred By: ASTM B1009-20 - Standard Specification for Titanium Alloy Bars for Near Surface Mounts in Civil Structures
• Effective Date: 10-Nov-1999
• Referred By: ASTM A1124/A1124M-23 - Standard Specification for Textured Epoxy-Coated Steel Reinforcing Bars
• Effective Date: 10-Nov-1999
• Referred By: ASTM D7913/D7913M-14(2020) - Standard Test Method for Bond Strength of Fiber-Reinforced Polymer Matrix Composite Bars to Concrete by Pullout Testing
• Effective Date: 10-Nov-1999
• Referred By: ASTM A1055/A1055M-22 - Standard Specification for Zinc and Epoxy Dual-Coated Steel Reinforcing Bars
• Effective Date: 10-Nov-1999
• Referred By: ASTM A934/A934M-22 - Standard Specification for Epoxy-Coated Prefabricated Steel Reinforcing Bars
• Effective Date: 10-Nov-1999

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: A 944 – 99
Standard Test Method for
Comparing Bond Strength of Steel Reinforcing Bars to
Concrete Using Beam-End Specimens
This standard is issued under the fixed designation A 944; 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 3.1.4 embedment length, n—the distance from the surface of
the concrete test specimen to the installed end of the steel
1.1 This test method describes procedures to establish the
reinforcing bar. This equals the sum of the lead length and the
relative bond strength of steel reinforcing bars in concrete.
bonded length.
1.2 This test method is intended to determine the effects of
3.1.5 lead length, n—the length of the test bar that is not in
surface preparation or condition (such as bar coatings) on the
contact with concrete but is between the surface of the concrete
bond strength of deformed steel reinforcing bars (of sizes
test specimen and the bonded length.
ranging from No. 10 to No. 36 [No. 3 to No. 11]) to concrete.
3.1.6 relative rib area, n—ratio of the projected rib area
1.3 The values stated in SI units are to be regarded as the
normal to bar axis to the product of the nominal bar perimeter
standard. The values given in brackets are for information only.
and the center-to-center rib spacing.
1.4 This standard does not purport to address all of the
3.2 Symbols:
safety concerns, if any, associated with its use. It is the
C = Concrete cover, mm [in.].
b
responsibility of the user of this standard to establish appro-
d = Nominal diameter of reinforcing bar, mm [in.].
b
priate safety and health practices and determine the applica-
l = Embedment length, mm [in.].
e
bility of regulatory limitations prior to use.
4. Apparatus
2. Referenced Documents
4.1 Equipment—A schematic of a suitable testing system is
2.1 ASTM Standards:
shown in Fig. 1. The loading system shall be capable of
C 192/C 192M Practice for Making and Curing Concrete
measuring the forces to an accuracy within 62 % of the
Test Specimens in the Laboratory
applied load, when calibrated in accordance with Practices E 4.
E 4 Practices for Force Verification of Testing Machines
The test system shall have sufficient capacity to prevent
E 575 Practice for Reporting Data from Structural Tests of
yielding of its various components and shall ensure that the
Building Constructions, Elements, Connections, and As-
applied tensile load remains parallel to the axis of the steel
semblies
reinforcing bar during testing.
3. Terminology
4.2 Compression Reaction Plate—The compression reac-
tion plate shall be placed a minimum clear distance equal to 0.9
3.1 Definitions of Terms Specific to This Standard:
l measured from the center of the test bar to the edge of the
3.1.1 bond strength, n—maximum measured load in a e
reaction plate.
tensile bond test of a steel reinforcing bar.
4.3 Bar Displacement Measurements—Displacements of
3.1.2 bonded length, n—the length of the test bar that is in
the loaded and free ends of the steel reinforcing bar shall be
contact with concrete.
measured with respect to the loaded and free surfaces, respec-
3.1.3 concrete cover, n—minimum distance between the
tively, of the concrete using suitable measurement devices.
surface of the test bar and the top or bottom of the test
Dial gages having the smallest division of not more than 25 μm
specimen.
[0.001 in.] or linear variable differential transformers (LVDTs)
with equal or superior accuracy are examples of satisfactory
devices.
This test method is under the jurisdiction of ASTM Committee A-1 on Steel,
Stainless Steel, and Related Alloys and is the direct responsibility of Subcommittee
5. Test Specimen
A01.05 on Steel Reinforcement.
Current edition approved Nov. 10, 1999. Published January 2000. Originally
5.1 Beam-End Specimen—The test specimen shall consist
published as A 944 – 95. Last previous edition A 944 – 95.
of the test bar cast in a block of reinforced concrete 600 6 25
Annual Book of ASTM Standards, Vol 04.02.
mm [24 6 1 in.] long by d + 200 6 13 mm [d +8 6 ⁄2 in.]
Annual Book of ASTM Standards, Vol 03.01. b b
Annual Book of ASTM Standards, Vol 04.07. wide by a minimum of d +C +l +60mm[d +C +l +2 ⁄2
b b e b b e
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A 944–99
FIG. 1 Schematic of Test Apparatus
NOTE 1—The lead length, shown in Fig. 2, is typically between 13 and
in.] high. A typical test specimen is illustrated in Fig. 2. The
100 mm [0.5 and 4 in.]. This unbonded region is used to prevent a
specimen shall be reinforced by four closed stirrups oriented
cone-type pullout failure at the surface of the concrete. Increases in lead
parallel to the sides of the specimen and two flexural steel
length generally result in an increase in bond strength.
reinforcing bars parallel to the test bar, as shown in Fig. 2.
Transverse steel reinforcing bars similar to those illustrated in 5.2 Fabrication—The concrete block shall be fabricated
using concrete designed to produce a strength at the time of test
Fig. 2 may be used to aid in fabrication and testing. The test bar
shall extend from the front surface a distance that is compatible between 31 and 38 MPa [4500 and 5500 psi]. The specimen
shall be cast in approximately equal layers not exceeding 250
with the test
...