ASTM C1531-03

Standard Test Methods for In Situ Measurement Of Masonry Mortar Joint Shear Strength Index

SIGNIFICANCE AND USE
The masonry mortar joint shear strength index obtained by this test method is related to the masonry wall shear strength by a relationship contained within Appendix Chapter 1 of the Uniform Code for Building Conservation. The user of this standard is cautioned that the shear strength relationship contained within the Uniform Code for Building Conservation is an empirical relationship based on tests of early 20th-century unreinforced brick masonry. The relationship assumes that wall shear strength is limited by shear of the mortar joints rather than shear through the units.
For hollow ungrouted or solid unit masonry construction the shear strength index is measured only for the mortar bed joints vertically adjacent to the unit being tested. When testing hollow ungrouted masonry construction, the shear strength index is based on the horizontal interface between the mortar and the test unit and the masonry above and below the test unit. In the case of multi-wythe construction, the measured mortar joint shear strength index is applicable only to the wythe in which the test unit is located; no headers shall exist immediately above or below the test unit. The contribution of any existing collar joint mortar to the measured shear strength index is neglected, and this may lead to an overestimate of the shear strength index.
The test procedure listed for Method A may be conducted as an extension of Test Method C 1197. The two-flatjack test, conducted in accordance with Test Method C 1197, provides half of the required test setup for Method A. At the completion of the Method A test, one would know the measured normal compressive stress, the deformability of the masonry at the test, and the relationship between the expected joint shear strength index and the normal compressive stress.
SCOPE
1.1 These test methods cover procedures for the determination of the average in situ mortar joint shear strength index in existing unreinforced solid-unit and ungrouted hollow-unit masonry built with clay or concrete units. Three methods are provided:
1.1.1 Method A (with Flatjacks Controlling Normal Compressive Stress)—For determining mortar joint shear strength index when the state of normal compressive stress at the test site is controlled during the test using the flatjack method described in Test Method C 1197. Horizontal displacement of the test unit is monitored throughout the test. The test setup for Method A is shown in .
1.1.2 Method B (without Flatjacks Controlling Normal Compressive Stress)—For determining mortar joint shear strength index when using an estimate of the normal compressive stress at the location of the test site. Horizontal displacement of the test unit is not monitored during this procedure. The test set up for Method B is shown in .
1.1.3 Method C (with Flatjack Applying Horizontal Load)—For determining mortar joint shear strength index using an estimate of the normal compressive stress at the location of the test site, as shown in . Horizontal displacement of the test unit is generally not measured during this procedure.
1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.
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 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-Jan-2003
• ICS: 91.080.30 - Masonry
• Technical Committee: C15 - Manufactured Masonry Units
• Drafting Committee: C15.04 - Research

Relations

• Replaces: ASTM C1531-02 - Standard Test Methods for In Situ Measurement Of Masonry Mortar Joint Shear Strength Index
• Effective Date: 10-Jan-2003
• Replaced By: ASTM C1531-09 - Standard Test Methods for In Situ Measurement Of Masonry Mortar Joint Shear Strength Index
• Effective Date: 01-Jun-2009

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: C 1531 – 03
Standard Test Methods for
In Situ Measurement Of Masonry Mortar Joint Shear
1
Strength Index
This standard is issued under the fixed designation C 1531; 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* C 1180 Terminology of Mortar and Grout for Unit Ma-
2
sonry
1.1 These test methods cover procedures for the determina-
C 1196 Test Method for In Situ Compressive Stress Within
tion of the average in situ mortar joint shear strength index in
Solid Unit Masonry Estimated Using Flatjack Measure-
existing unreinforced solid-unit and ungrouted hollow-unit
2
ments
masonry built with clay or concrete units. Three methods are
C 1197 Test Method for In Situ Measurement of Masonry
provided:
2
Deformability Properties Using the Flatjack Method
1.1.1 Method A (with Flatjacks Controlling Normal Com-
C 1209 Terminology of Concrete Masonry Units and Re-
pressive Stress)—For determining mortar joint shear strength
2
lated Units
index when the state of normal compressive stress at the test
2
C 1232 Terminology of Masonry
site is controlled during the test using the flatjack method
3
E 4 Practices for Force Verification of Testing Machines
described in Test Method C 1197. Horizontal displacement of
2.2 Other Document:
the test unit is monitored throughout the test. The test setup for
Uniform Code for Building Conservation (Appendix Chap-
Method A is shown in Fig. 1.
ter 1, Earthquake Hazard Reduction in Existing Unrein-
1.1.2 Method B (without Flatjacks Controlling Normal
forced Masonry Buildings), International Conference of
Compressive Stress)—For determining mortar joint shear
Building Officials, Whittier, CA, 1997
strength index when using an estimate of the normal compres-
sive stress at the location of the test site. Horizontal displace-
3. Terminology
ment of the test unit is not monitored during this procedure.
3.1 Terminology defined in Terminologies C 43, C 1180,
The test set up for Method B is shown in Fig. 2.
C 1209, and C 1232 shall apply for these test methods.
1.1.3 MethodC(withFlatjackApplyingHorizontalLoad)—
For determining mortar joint shear strength index using an
4. Summary of Test Method
estimate of the normal compressive stress at the location of the
4.1 The in-place shear test is used to provide an index of the
test site, as shown in Fig. 3. Horizontal displacement of the test
in situ, horizontal shear resistance of mortar joints in unrein-
unit is generally not measured during this procedure.
forced masonry. For Method A, a single masonry unit is
1.2 The values stated in inch-pound units are to be regarded
removed from opposite ends of the chosen test unit as shown
as the standard. The values given in parentheses are for
in Fig. 1. For Method B, a single masonry unit and a head joint
information only.
are removed from opposite ends of the chosen test unit, as
1.3 This standard does not purport to address all of the
shown in Fig. 2. For Method C, head joints on both ends of the
safety concerns, if any, associated with its use. It is the
tested unit are removed as shown in Fig. 3. Ensure that the bed
responsibility of the user of this standard to establish appro-
joints are not disturbed in the unit to be tested. The test unit is
priate safety and health practices and determine the applica-
thendisplacedhorizontallyrelativetothesurroundingmasonry
bility of regulatory limitations prior to use.
using a hydraulic jack or specialized flatjacks. The horizontal
2. Referenced Documents force required to cause first movement of the test unit provides
a measured index of the mortar joint shear strength.
2.1 ASTM Standards:
2
C 43 Terminology of Structural Clay Products
5. Significance and Use
5.1 The masonry mortar joint shear strength index obtained
bythistestmethodisrelatedtothemasonrywallshearstrength
1
These test methods are under the jurisdiction of ASTM Committee C15 on
by a relationship contained within Appendix Chapter 1 of the
Manufactured Masonry Units and are the direct responsibility of Subcommittee
Uniform Code for Building Conservation. The user of this
C15.04 on Research.
Current edition approved Jan. 10, 2003. Published September 2003. Originally
approved in 2002. Last previous edition approved in 2002 as C 1531–02.
2 3
Annual Book of ASTM Standards, Vol 04.05 Annual Book of ASTM Standards, Vol 03.01.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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C1531–03
FIG. 1 Test
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