Properties of Aggregates and its Values for use in Construction
Properties of Aggregates and its Values for use in Construction
Properties of aggregates such as bulk density, specific gravity, voids, water absorption and its values are presented in this article.
1. Aggregates: Bulk Density, Specific Gravity and Voids
| Bulk Density |
| River sand |
| Fine | 1.44 |
| Medium | 1.52 |
| Coarse | 1.60 |
| Beach or river shingle | 1.60 |
| Broken stone | 1.60 |
| Stone screenings | 1.44 |
| Broken Granite | 1.68 |
| Specific Gravity |
| Trap | 2.9 |
| Granite | 2.8 |
| Gravel | 2.66 |
| Sand | 2.65 |
| Voids, Percent, Average |
| River sand |
| Fine | 43 |
| Coarse | 35 |
| Mixed and moist | 38 |
| Mixed and dry | 30 |
| Broken stone, graded |
| 25 mm maximum size | 46 |
| 50 mm maximum size | 45 |
| 63 mm maximum size | 41 |
| Stone screenings | 48 |
Note: Above values are indicative only
2. Aggregates: Limiting Values of Mechanical Properties
| Properties | Limiting Values (Percentage) |
| For Wearing Surfaces | Other Than for Wearing Surfaces |
| Crushing value | 30 | 45 |
| Impact value | 30 | 45 |
| Abrasion value (Los Angeles) | 30 | 50 |
| Soundness (Average loss of weight after 5 cycles) | When tested with Na2SO4 | When tested with MgSO4 |
| Fine aggregates | 10 | 15 |
| Coarse aggregates | 12 | 18 |
*Source- IS: 383 – 1970
3. Approximate Water Absorption of Aggregates, by Weight
| Average sand | 1.0 percent |
| Pebbles and crushed limestone | 1.0 percent |
| Trap rock and granite | 0.5 percent |
| Porous sandstone | 0.5 percent |
| Very light and porous aggregates may absorb as much as | 25 percent by weight |
Note: The coarser the aggregate, the less free water it carries.
4. Limits of Deleterious Materials (Percentage by Weight, Maximum)
(Clause 3.2.1 of IS: 383 – 1970
| Deleterious Substances | Fine Aggregates | Coarse Aggregates |
| Uncrushed | Crushed | Uncrushed | Crushed |
| Coal and lignite | 1.00 | 1.00 | 1.00 | 1.00 |
| Clay lumps | 1.00 | 1.00 | 1.00 | 1.00 |
| Materials finer than 75-micron sieve | 2.00 | 15.00 | 3.00 | 3.00 |
| Shale | 1.00 | - | - | - |
| Total of percentages of all deleterious materials ** | 5.00 | 2.00 | 5.00 | 5.00 |
**Mica is excluded.
5. Bulking of Sands for Various Moisture Contents
| Moisture, percent | Percentage bulking in |
| Fine sand | Medium sand | Coarse sand |
| 1 | 16 | 8 | 6 |
| 2 | 26 | 16 | 12 |
| 3 | 32 | 22 | 15 |
| 4 | 36 | 27 | 17 |
| 5 | 38 | 29 | 18 |
| 6 | 37 | 28 | 18 |
| 8 | 35 | 26 | 16 |
| 10 | 32 | 22 | 12 |
| 12 | 28 | 19 | 8 |
| 15 | 22 | 12 | 2 |
| 17 | 18 | 7 | 0 |
| 20 | 9 | 0 | 0 |
| 27 | 0 | 0 | 0 |
6. Surface Water Carried by Aggregates
| Aggregates | Approximate Qty of Surface Water |
| Percent by mass | Ltr./cu.m |
| Very wet sand | 7.5 | 120 |
| Moderately wet sand | 5.0 | 80 |
| Moist sand | 2.5 | 40 |
| Moist gravel or crushed rock | 1.25 – 2.5 | 20 – 40 |
Note: Coarser the aggregate, less the water it will carry. Source: Table 10 of IS: 456 – 2000
