ASTM C1072-22 - 1.12.2022
 
Significance and Use

5.1?This test method is intended for use in comparing the bond strengths (under the given conditions) of masonry mortars.

5.2?This test method could be used, for example, to check one aspect of the quality of mortar products after production, or to indicate the bond potential of a mortar product without requiring the product to be tested in combination with many different units.

5.3?This test method uses controlled conditions of fabrication and curing that are not intended to represent field conditions.

5.4?This test method uses standard concrete masonry units. Mortars are batched by weight equivalents of volume proportions and are mixed to a prescribed flow. Prisms are constructed using a jig and are bag-cured.

5.5?Flexural bond strength determined by this test method shall not be interpreted as the flexural bond strength of a wall (because standard units are not used for wall construction), nor shall it be interpreted as an indication of extent of bond for purposes of water permeability evaluation.

 
1. Scope

1.1?These test methods evaluate the flexural bond strength, normal to the bed joints, of masonry built of manufactured masonry units. Sampling and testing procedures are referenced, and terms are defined. Three different specimen fabrication methods are specified, each for a different purpose:

1.1.1?The first method is the Test Method for Laboratory-Prepared Specimens. Its purpose is to compare the bond strengths (under the given conditions) of masonry mortars. It could be used, for example, to check the quality of mortar products after production, or to indicate the bond strength (under the given conditions) of a mortar product without requiring the product to be tested in combination with many different units. It is not intended to represent field conditions. It uses standard concrete masonry units. Mortars are batched by weight equivalents of volume proportions and are mixed to a prescribed flow. Prisms are constructed using a jig and are bag-cured.

1.1.2?The second method is the Test Method for Field-Prepared Specimens. Its purpose is to evaluate the bond strength (under the given conditions) of a particular unit-mortar combination, either for preconstruction evaluation of materials or for quality control purposes during construction. Mortars are batched conventionally, and the flow is not prescribed. Prisms are constructed conventionally (no jig) and are bag-cured.

1.1.3?The third method is the Test Method for Prisms Removed from Existing Masonry. Its purpose is to evaluate the bond strength of unit-mortar combinations of prisms cut from existing walls.

1.1.4?The three methods are not consistent, nor are they intended to be. They are intended to be used for three different purposes. To make this clear, the three methods are presented separately.

1.1.5?Appendix X1 suggests two possible criteria for assessing the bond strength values obtained using these test methods. These possible evaluation criteria are given for illustration only and are not mandatory.

1.2?The text of this standard refers to notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.

1.3?The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

 
2. Referenced Documents

C230/C230M-23

Standard Specification for Flow Table for Use in Tests of Hydraulic Cement

C67-17

Standard Test Methods for Sampling and Testing Brick and Structural Clay Tile

C140-13

Standard Test Methods for Sampling and Testing Concrete Masonry Units and Related Units

C1437-20

Standard Test Method for Flow of Hydraulic Cement Mortar

C1232-23

Standard Terminology for Masonry

C780-23

Standard Test Methods for Preconstruction and Construction Evaluation of Mortars for Plain and Reinforced Unit Masonry

TMS?402/ACI?530/ASCE?5

Building Code Requirements for Masonry Structures Available from the Masonry Standards Joint Committee, http://www.masonrystandards.org.

C270-19ae1

Standard Specification for Mortar for Unit Masonry (Includes all amendments and changes 1/4/2024).

C1532-06

Standard Practice for Selection, Removal, and Shipment of Manufactured Masonry Units and Masonry Specimens from Existing Construction

NBS Handbook

91 Natrella, M. G.,Experimental Statistics, National Bureau of Standards Handbook 91, U.S. Government Printing Office, Aug. 1, 1963, pp. 2-14.