FAB performance versus clay brick and concrete brick (at a glance), based on modular size:
| Brick Type | Fly Ash Brick (FAB) | Clay Brick | Concrete Brick |
|---|---|---|---|
| Embodied energy | 0.89 – 1.31 MJ (850 – 1,250 BTUs) |
9.3 MJ (8,800 BTUs) |
1.3 MJ (1,240 BTUs) |
| CO2 | 0.11 kg (0.25 lbs) |
0.59 kg (1.3 lbs) |
0.34 kg (0.53 lbs) |
| Recycled material | 40%. No CO2-intensive cement is included in CalStar’s products. |
0 – 6%. Energy intensity of the product remains unchanged. |
Not typical. Where fly ash or slag is substituted for up to 30% of cement, this represents only about 5% of total product weight. |
| Installed performance | Shrinkage substantially less than 0.065% | No shrinkage | Shrinkage no more than 0.065% |
| Dimensional consistency | Very consistent | Varies (based on firing) |
Very consistent |
| Initial Rate of Absorption (1 – 14 g/30in”/min) |
1 – 14 | 2 – 30 | > 25 |
| Pigments | Natural and synthesized | Natural and synthesized | Natural and synthesized |
Source: The Construction Specifier

