The Constructor

Properties of Aggregates and its Values for use in Construction

Civil Engineering

Reading time: 1 minute

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
Exit mobile version