ASTM C279-23

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C279 − 17 C279 − 23
Standard Specification for
Chemical-Resistant Masonry Units
This standard is issued under the fixed designation C279; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This specification covers solid, kiln fired brick and tile made from clay, shale, or mixtures thereof, suitable for indoor and
outdoor use in masonry construction subjected to chemical environments (see Terminology environments.C1232).
1.2 The brick and tile covered herein are intended for use in chemical environments where resistance to thermal shock may be
a consideration. The brick and tile are normally used with chemical-resistant mortars.
1.3 The values stated in inch-pound units are to be regarded as 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 and healthsafety, 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
2.1 ASTM Standards:
C20 Test Methods for Apparent Porosity, Water Absorption, Apparent Specific Gravity, and Bulk Density of Burned Refractory
Brick and Shapes by Boiling Water
C67C67/C67M Test Methods for Sampling and Testing Brick and Structural Clay Tile
C1232 Terminology for Masonry
E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves
3. Terminology
3.1 Definitions—For definitions relating to chemical-resistant masonry units, refer to Terminology C1232.
This specification is under the jurisdiction of ASTM Committee C15 on Manufactured Masonry Units and is the direct responsibility of Subcommittee C15.02 on Brick
and Structural Clay Tile.
Current edition approved June 1, 2017June 1, 2023. Published July 2017June 2023. Originally approved in 1951. Last previous edition approved in 20132017 as
C279 – 13a.C279 – 17. DOI: 10.1520/C0279-17.10.1520/C0279-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*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
C279 − 23
4. Classification
4.1 The physical and chemical properties of brick and tile differ from supplier to supplier, mainly because their composition is
determined by the source of raw materials. Regardless of the differences, brick and tile are considered to be one of three types and
one of two classes as follows:
4.1.1 Type I—For use where low absorption and high acid resistance are not major factors.
4.1.2 Type II—For use where lower absorption and higher acid resistance are required.
4.1.3 Type III—For use where minimum absorption and maximum acid resistance are required.
NOTE 1—Types I, II, and III may not differ significantly in thermal shock resistance. The suitability of a given brick, for a particular application should
be determined at the time of purchase by agreement between the purchaser and the supplier.
NOTE 2—Types I and III were formerly designated Type “H” and “L” respectively.
4.1.4 Class S—For use in standard applications.
4.1.5 Class X—For use where a higher degree of precision and lower permissible variation in size than that permitted for Class
S is required.
5. Physical Properties and Chemical Resistance Requirements
5.1 Strength—The brick and tile when tested in accordance with Test Methods C67C67/C67M shall conform to the requirements
for modulus of rupture (flexural strength) for the type specified, as prescribed in Table 1.
5.2 Water Absorption—The brick and tile when tested in accordance with Test Methods C20 shall conform to the requirements
for water absorption (based on the 2 h boil) for the type specified, as prescribed in Table 1.
5.3 Sulfuric Acid Solubility—When tested in accordance with Section 8, the brick and tile shall conform to the requirements for
sulfuric acid solubility for the type specified, as prescribed in Table 1.
6. Dimensions and Permissible Variations
6.1 Sizes—The sizes of the brick and tile shall be as specified by the purchaser. The length, width, and depth measurements of the
brick or tile shall be within 63 % of the specified dimensions for Class S units and within 61.5 % of the specified dimensions
for Class X units.
6.2 Warpage—The brick and tile shall conform to the requirements as shown in Table 2.
7. Finish and Appearance
7.1 Surface Textures—Brick or tile surfaces are often textured in order to promote better bonding. Texturing is accomplished by
scoring, wire cutting, matting, or other means consistent with a manufacturer’s process. If texturing is done, the protrusion or
indentation shall not exceed ⁄8 in. (3 mm) in depth.
TABLE 1 Physical Properties and Chemical Resistance
Requirements for Brick and Tile
Modulus of Rupture Water Absorption H SO Solubility
2 4
(Brick or Tile Flat- Maximum % by Maximum %
wise) min. psi (MPa) 2 h Boiling Test Weight Loss
Designation
Average of 5 Average of 5
Average of 5
Brick or Tile Brick or Tile
Brick or Tile
Low Individual High Individual
Type I 1250 (8.6) 1000 (6.9) 6.0 7.0 20
Type II 1250 (8.6) 1000 (6.9) 4.0 5.0 12
Type III 1250 (8.6) 1000 (6.9) 1.0 1.5 8
C279 − 23
TABLE 2 Tolerances on Warpage
Minimum Face Dimensions, Maximum Permissible Warpage, inches
inches (mm) (mm)
Class S Class X
3 3
8 (203) and under ⁄32 (2.4) ⁄64 (1.2)
1 1
over 8 to 12 (203 to 305), incl ⁄8 (3.2) ⁄
...