ASTM C1531-02 - 10.6.2002
 
1. 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.

 
2. Referenced Documents

ASCE/SEI 41

Seismic Evaluation and Retrofit of Existing Buildings, ASCE Standard ASCE/SEI 41 (Chapter 11, Masonry) Available from American Society of Civil Engineers (ASCE), 1801 Alexander Bell Dr., Reston, VA 20191, http://www.asce.org.

International Existing Building Code

(Appendix A, Chapter A1, Seismic Strengthening Provisions for Unreinforced Masonry Bearing Wall Buildings), 2014 Available from International Code Council, 4051 Flossmoor Road, Country Club Hills, IL 60478.

E4-24

Standard Practices for Force Calibration and Verification of Testing Machines

C1232-26a

Standard Terminology for Masonry (Includes all amendments and changes 8/20/2026).

C1197-22

Standard Test Method for In Situ Measurement of Masonry Deformability Properties Using the Flatjack Method

C1196-20

Standard Test Method for In Situ Compressive Stress Within Solid Unit Masonry Estimated Using Flatjack Measurements

C1180-24

Standard Terminology of Mortar and Grout for Unit Masonry (Withdrawn 2025)