ASTM C270-07a - 15.12.2007
 
1. Scope

1.1 This specification covers mortars for use in the construction of non-reinforced and reinforced unit masonry structures. Four types of mortar are covered in each of two alternative specifications: (1) proportion specifications and (2) property specifications.

Note 1—- When the property specification is used to qualify masonry mortars, the testing laboratory performing the test methods should be accredited in accordance with Practice C 1093.

1.2 The proportion or property specifications shall govern as specified.

1.3 When neither proportion or property specifications are specified, the proportion specifications shall govern, unless data are presented to and accepted by the specifier to show that mortar meets the requirements of the property specifications.

1.4 The text of this specification references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.

1.5 The terms used in this specification are identified in Terminologies C 1180 and C 1232.

1.6 The following safety hazards caveat pertains only to the test methods section of this specification: 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

C1072-26

Standard Test Methods for Measurement of Masonry Flexural Bond Strength

C91-05

Standard Specification for Masonry Cement

C1157-08

Standard Performance Specification for Hydraulic Cement

C1180-24

Standard Terminology of Mortar and Grout for Unit Masonry (Withdrawn 2025)

C1232-26a

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

C110-24

Standard Test Methods for Physical Testing of Quicklime, Hydrated Lime, and Limestone

C128-25

Standard Test Method for Relative Density (Specific Gravity) and Absorption of Fine Aggregate

C144-26

Standard Specification for Aggregate for Masonry Mortar

C150-07

Standard Specification for Portland Cement

C188-26

Standard Test Method for Density and Relative Density of Hydraulic Cement

C207-24

Standard Specification for Hydrated Lime for Masonry Purposes

C305-20

Standard Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic Consistency

C1093-25

Standard Practice for Accreditation of Testing Agencies for Masonry

C5-24

Standard Specification for Quicklime for Structural Purposes

C109/C109M-26a

Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 50 mm [2 in.] Cube Specimens) (Includes all amendments and changes 7/30/2026).

C979-05

Standard Specification for Pigments for Integrally Colored Concrete

C952-12

Standard Test Method for Bond Strength of Mortar to Masonry Units (Withdrawn 2018)

C780-26

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

C595-08

Standard Specification for Blended Hydraulic Cements

C511-21

Standard Specification for Mixing Rooms, Moist Cabinets, Moist Rooms, and Water Storage Tanks Used in the Testing of Hydraulic Cements and Concretes

C1324-25e1

Standard Test Method for Examination and Analysis of Hardened Masonry Mortar (Includes all amendments and changes 9/1/2026).

Hot and Cold Weather Masonry Construction Manual,

January 1999

C1329-05

Standard Specification for Mortar Cement

C1384-23

Standard Specification for Admixtures for Masonry Mortars

C1489-15(2022)

Standard Specification for Lime Putty for Structural Purposes

C1506-24

Standard Test Method for Water Retention of Hydraulic Cement-Based Mortars and Plasters

C1586-26

Standard Guide for Quality Assurance of Mortars

E72-25

Standard Test Methods of Conducting Strength Tests of Panels for Building Construction

E514-08

Standard Test Method for Water Penetration and Leakage Through Masonry

E518-09

Standard Test Methods for Flexural Bond Strength of Masonry