Masonry Magazine December 1989 Page. 29
TABLE 3
Appearance
| ASTM Standard | Tighter Tolerances | Looser Tolerances |
|---|---|---|
| C 62 | None | None |
| C 216 Type | FBX | FBS | FBA |
| C 652 Type | HBX | HBS | HBB | HBA |
| C 902 Application | PX | PS | PA |
| C 126 Grade | S | SS | - |
| C 1088 Type | TBX | TBS | TBA |
| C 32 Sewer | | None |
| | Manhole | None |
Waivers. Because of the variability of raw materials and production methods throughout the country, it is difficult to use only these requirements to classify all brick. Therefore, in each standard there are waivers which include those brick which are durable but cannot be classified under the physical requirements. Using the waiver permits the use of brick which are known to perform well. It does not signify that the brick are of a lower quality. Waivers include: waiving the saturation coefficient and water absorption requirements if brick are intended to be used where the weathering index is less than 50; waiving the saturation coefficient requirement if the cold water absorption is less than 8% on an average of five units allowing one brick of the sample to exceed 8% but be less than 10%; waiving the saturation coefficient and water absorption requirements if the sample complies with the 50 cycle freeze and thaw test requiring no breakage and not greater than 0.5% loss in dry weight of any individual brick (Grade SW only). Freeze-thaw requirements apply only if the units do not meet the saturation coefficient and absorption requirements. For waivers specific to each type of brick, consult the appropriate ASTM Specification.
Efflorescence
Efflorescence is a crystalline deposit of water-soluble salts which forms on the surface of masonry. The principal objection is an unsightly appearance, though it typically is not harmful to brick. The test for efflorescence is described in ASTM C 67. The brick is given a rating of "effloresced" or "not effloresced". ASTM standards (C 216, C 652, C 902, C 1088) require the rating for brick to be "not effloresced".
Although brick is the only material in masonry construction that is tested for efflorescence, brick itself is not a major source of efflorescing salts.
TABLE 4
Physical Properties
| ASTM Standard | | Minimum Compressive Strength (psi) | | Maximum Cold Water Absorption (%) | | Maximum 5 Hr Boiling Absorption (%) | | Maximum Saturation Coefficient | |
|---|---|---|---|---|---|---|---|---|---|
| | | Avg of 5 Brick | Individual | Avg of 5 Brick | Individual | Avg of 5 Brick | Individual | Avg of 5 Brick | Individual |
| C 62 | SW | 3,000 | 2,500 | - | - | 17.0 | 20.0 | 0.78 | 0.80 |
| | MW | 2,500 | 2,200 | - | - | 22.0 | 25.0 | 0.88 | 0.90 |
| | NW | 1,500 | 1,250 | - | - | No Limit | No Limit | No Limit | No Limit |
| C 216 | SW | 3,000 | 2,500 | - | - | 17.0 | 20.0 | 0.78 | 0.80 |
| | MW | 2,500 | 2,200 | - | - | 22.0 | 25.0 | 0.88 | 0.90 |
| C 652 | SW | 3,000¹ | 2,500¹ | - | - | 17.0 | 20.0 | 0.78 | 0.80 |
| | MW | 2,500¹ | 2,200¹ | - | - | 22.0 | 25.0 | 0.88 | 0.90 |
| C 902 | SX | 8,000 (4,000)² | 7,000 (3,500)² | 8 (16)² | 11 (18)² | - | - | 0.78 | 0.80 |
| | MX | 3,000 | 2,500 | 14 | 17 | - | - | No Limit | No Limit |
| | NX | 3,000 | 2,500 | No Limit | No Limit | - | - | No Limit | No Limit |
| C 126 | Vertical | 3,000 | 2,500 | - | - | - | - | - | - |
| | Coring Horizontal | 2,000 | 1,500 | - | - | - | - | - | - |
| C1088 | Exterior | - | - | - | - | 17.0 | 20.0 | 0.78 | 0.80 |
| | Interior | - | - | - | - | 22.0 | 25.0 | 0.88 | 0.90 |
| C 32 | SS | 8,000 | 6,000 | - | - | 6.0 | 9.0 | - | - |
| | SM | 5,000 | 3,750 | - | - | 12.0 | 15.0 | 0.80³ | - |
| | MS | 3,000 | 2,500 | - | - | 17.0 | 20.0 | 0.80³ | - |
| | MM | 2,500 | 2,200 | - | - | 22.0 | 25.0 | 0.90 | - |
¹Hollow brick in bearing position.
²Numbers in parentheses are for molded brick and apply provided the requirements for saturation coefficient are met.
³Where a high and uniform degree of resistance to frost action in the presence of moisture is required. See C 32 for waiver of saturation coefficient.