Physical Properties of Building Bricks - ASTM Standards

The physical properties of building bricks used for both structural and non-structural properties in construction are provided by American Standard of Testing Materials (ASTM) in the standard code ASTM C 62-99, which is the "Standard Specification for Building Bricks (Solid Masonry Units Made from Clay or Shale). 

The physical properties of solid building bricks made out of clay or shale as per the ASTM standards are explained below.

Physical Properties of Solid Building Bricks

1. Appearance of Solid Building Bricks

Building bricks if require a proper texture, uniformity, color, finish, etc, then they must be purchased by looking into the specifications given for facing bricks as per ASTM C126, "Specification for Facing Brick (Solid Masonry Units Made from Clay or Shale)".

2. Durability

The solid brick can be classified into Grade SW, Grade MW, and Grade NW. Unless specified, an SW-type solid brick is always preferred. 

Read More On: Different Grades of Solid Bricks - ASTM Standard C62-99

3.  Compressive Strength as per ASTM C 62-99

The bricks used must have compressive strength appropriate for each grade, as given in the table below. To determine the compressive strength, the unit is tested with the compressive force perpendicular to the bed surface of the unit, with the unit in the stretcher position.

4. Absorption Alternate

If the single unit of a random sample of five bricks has a cold water absorption rate not greater than 8 percent, the saturation coefficient mentioned in the table above does not apply.

5. Freezing and Thawing Alternative

The requirements for 5 h boiling water absorption and saturation coefficient do not apply, provided a sample of five bricks, meeting the strength requirements of Table 1, passes the freezing and thawing test as described in the Rating Section of the Freezing and Thawing test procedures of Test Methods of ASTM C 67. For Grade SW—Weight Loss Requirement—Not greater than 0.5 % loss in dry weight of any individual unit.

6. Waiver of Absorption and Saturation Coeffıcient Requirements

If the brick is intended for use exposed to weather where the weathering index is less than 50 (see Fig. 1), and unless otherwise specified, the requirements given in Table 1 for 5 h boiling water absorption and for saturation coefficient shall not apply but the minimum average compressive strength requirement of 2500 psi (17.2 MPa) shall apply.

7. Strength of Solid Building Bricks

When bricks are required to have strengths greater than prescribed by this specification, the purchaser shall specify minimum strength.

8.  Initial Rate of Absorption (IRA)

Test results for the initial rate of absorption (IRA) shall be determined in accordance with the IRA (Suction) (Laboratory Test) of Test Methods C 67 and shall be furnished at the request of the specifier or purchaser. IRA is not a qualifying condition or property of units in this specification. This property is measured in order to assist in mortar selection and material handling in the construction process.

Also Read: Classification of Bricks -ASTM Standards