ASTM D3931-93a(1999)e1

Standard Test Method for Determining Strength of Gap-Filling Adhesive Bonds in Shear by Compression Loading

SCOPE
1.1 This test method covers the determination of comparative shear properties of gap-filling adhesives in wood-to-wood joints at specified thicknesses of bondline in the dry condition, when tested on standard specimens under specified conditions of preparation, conditioning, and loading in compression. This test method is intended as an evaluation of gap-filling adhesives such as those used to bond plywood to lumber, lumber to lumber, and other similar materials in building constructions.  
1.2 This test method also may be used to determine shear properties of gap-filling adhesives in species of wood and in thicknesses of bondline other than those specified for the comparative tests of shear properties within this test method. All procedures specified herein are applicable, excepting requirements for wood species and specific gravity, and thicknesses of bondlines.  
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 whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Dec-1998
• ICS: 83.180 - Adhesives
• Technical Committee: D14 - Adhesives
• Drafting Committee: D14.70 - Construction Adhesives

Relations

• Replaced By: ASTM D3931-93a(2005) - Standard Test Method for Determining Strength of Gap-Filling Adhesive Bonds in Shear by Compression Loading
• Effective Date: 01-Apr-2005
• Referred By: ASTM D5574-94(2021) - Standard Test Methods for Establishing Allowable Mechanical Properties of Wood-Bonding Adhesives for Design of Structural Joints
• Effective Date: 01-Jan-1999
• Referred By: ASTM D6465-99(2016) - Standard Guide for Selecting Aerospace and General Purpose Adhesives and Sealants
• Effective Date: 01-Jan-1999
• Referred By: ASTM D3930-08(2023) - Standard Specification for Adhesives for Wood-Based Materials for Construction of Manufactured Homes
• Effective Date: 01-Jan-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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
e1
Designation:D3931–93a (Reapproved 1999)
Standard Test Method for
Determining Strength of Gap-Filling Adhesive Bonds in
Shear by Compression Loading
This standard is issued under the fixed designation D 3931; 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.
e NOTE—Keywords were added in April 1999.
1. Scope E 171 Specification for Standard Atmospheres for Condi-
tioning and Testing Materials
1.1 This test method covers the determination of compara-
tive shear properties of gap-filling adhesives in wood-to-wood
3. Terminology
joints at specified thicknesses of bondline in the dry condition,
3.1 Definitions:
when tested on standard specimens under specified conditions
3.1.1 gap-filling adhesive, n—an adhesive capable of form-
of preparation, conditioning, and loading in compression. This
ing and maintaining a bond between surfaces that are not
test method is intended as an evaluation of gap-filling adhe-
close-fitting.
sives such as those used to bond plywood to lumber, lumber to
3.1.1.1 Discussion—Close-fitting is relative to a given ma-
lumber, and other similar materials in building constructions.
terial and industry; for example, standards in construction
1.2 This test method also may be used to determine shear
differ from standards in electronics. Some adhesives will bond
properties of gap-filling adhesives in species of wood and in
by bridging without completely filling the gap; others by filling
thicknesses of bondline other than those specified for the
the gap completely.
comparative tests of shear properties within this test method.
All procedures specified herein are applicable, excepting re-
4. Significance and Use
quirements for wood species and specific gravity, and thick-
4.1 Structural design based on strength-of-materials prin-
nesses of bondlines.
ciples requires knowledge of the mechanical properties of the
1.3 This standard does not purport to address all of the
structural components, including adhesives. By nature of their
safety concerns, if any, associated with its use. It is the
use, the most important property of adhesive is shear strength.
responsibility of the user of this standard to establish appro-
4.2 Shear strength measured by this test method is suitable
priate safety and health practices and determine the applica-
for use in adhesive development, manufacturing quality con-
bility of regulatory limitations prior to use.
trol, and in materials performance specifications, as well as
structural design.
2. Referenced Documents
2.1 ASTM Standards:
5. Apparatus
D 143 Methods of Testing Small Clear Specimens of Tim-
5.1 Testing Machine, having a capacity of about 15 000 lb
ber
(6818 kg) in compression or of sufficient capacity to test the
D 905 Test Method for Strength Properties of Adhesive
adhesive in use. The machine shall be fitted with a shearing
Bonds in Shear by Compression Loading
tool containing a self-aligning seat to ensure uniform lateral
D 1151 TestMethodforEffectofMoistureandTemperature
3 distribution of the load. The machine shall be capable of
on Adhesive Bonds
maintainingauniformrateofloadingsuchthattheloadmaybe
applied with a continuous motion of the movable head to
This test method is under the jurisdiction of ASTM Committee D-14 on maximum load at a rate of 9.20 in. (5.0 mm)/min with a
Adhesives and is the direct responsibility of Subcommittee D14.70 on Construction
permissible variation of 625 %. The shearing tool shown in
Adhesives.
Fig. 1 of Test Method D 905 has been found satisfactory.
Current edition approved Dec. 15, 1993. Published February 1994. Originally
published as D 3931 – 80. Last previous edition D 3931 – 90.
Annual Book of ASTM Standards, Vol 04.10.
3 4
Annual Book of ASTM Standards, Vol 15.06. Annual Book of ASTM Standards, Vol 15.09.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D3931
3 1
Locate the testing machine in an atmosphere such that the approximately ⁄4 by 2 ⁄2 by 14 in. (19 by 63 by 356 mm) have
moisture content of the specimens, developed under the con- been found to be satisfactory for this purpose. The moisture
ditions prescribed in 7.3, is not noticeably altered during content shall be from 8 to 10 % (conditions prescribed in 7.3.1)
testing. based on ovendry weight as determined on representative
samples in accordance with the final measurement section
6. Test Specimen and Sample
under radial and tangential shrinkage and the weighing section
6.1 Test specimens for adhesive bonds shall conform to the under moisture determination in Test Methods D 143. Surface
form and dimensions shown in Fig. 1. Prepare bonded assem- the blocks just prior to gluing, preferably with a hand-feed
blies as described in 7.1. Prepare test specimens for testing as jointer. Make sure the surfaces remain unsanded and free from
described in 7.2. dirt.
6.2 Determine mean shear strengths of bonds at bondline 7.1.2 Use spacer strips to control bondlines to specified
thicknesses of 0.006 and 0.060 in. (0.15 and 1.52 mm). Tests
thicknesses between blocks. Spacers shall be wood veneer or
1 1
for strengths of bonds at other thicknesses, in addition to those plastic, and measure approximately ⁄2 by 3 ⁄2 in. (13 by 89
specified, shall be optional upon agreement between the
mm) long. Place spacers crosswise at the ends and center of the
manufacturer and the user. lower test joint block. Apply adhesive in sufficient quantity to
6.3 Test a minimum of 28 specimens, representing seven ensure squeezeout at the ends of the joint when blocks are
different bonded assemblies, to determine mean shear strengths under pressure (Note 2).
of bonds at each bondline thickness.
NOTE 2—If the adhesive is to be applied as an extruded bead, the bead
3 1
should be ⁄8 to ⁄2 in. (10 to 13 mm) in diameter to ensure squeezeout in
7. Procedure
bondlinethicknessesnear0.060in.(1.5mm).Useasmallerdiameterbead
7.1 Preparation of Bonded Assemblies: of adhesive for thinner bondlines.
7.1.1 Prepare bonded assemblies with hard maple blocks
7.1.2.1 Take care to avoid air entrapment in the bondline.
(Acer saccharum or Acer nigrum) conditioned as described in 1
Do not spread the adhesive closer than ⁄2 in. (13 mm) to any
7.3. The blocks shall have a minimum specific gravity of 0.65,
spacer because adhesive may be entrapped between block and
based on ovendry weight and ovendry volume (Note 1).
spacer, thereby increasing bondline thickness. Assemble the
blocks immediately, unless specified otherwise by agreement
NOTE 1—A method for selecting maple blocks of satisfactory specific
between the manufacturer and user of the adhesive. Apply a
gravity is described in theAppendix of Test Method D 905. For reference
tests, the specific gravity of blocks may be determined in accordance with
15-lb (7.0-kg) load uniformly over the entire bond area to
the Weight and Moisture Content Section under Nail Withdrawal of Test
ensure firm contact between spacers and blocks of the assem-
Methods D 143.
bly. Maintain the pressure on test joints at the conditions
7.1.1.1 These blocks shall be straight-grained and free of prescribed in 7.1.
defects, including knots, splits, birdseye, short grain, decay, 7.1.3 Curing time for bonded assemblies shall be as speci-
and any unusual discoloration within the shearing area. The fied by the manufacturer of the adhesive, or else 30 days in the
blocks shall be of suita
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