| Material |
Description |
Road
Use |
| Class
A - Graded Granular |
Aggregate
sizes from 75mm down to a maximum of 10% 63 microns in
grading. There should be no gaps in the grading.
CBR over 15%
Note:
It is often that the
aggregate size is 50mm or smaller down to 5mm.
|
Backfill
and Sub-base layers only. If it can be proved that the
material quality is equal to that of a Granular
Sub-base Type 1, it may be used in the road base. |
| Class
B - Granular |
Aggregate
sizes from 75mm down to a maximum of 10% 63 microns in
grading. The percentages of the aggregate grades will
be less than that of a Class A material with a higher
percentage of fines.
CBR 7% to 15%
Note:
It is often that the aggregate size is 50mm or smaller
down to 5mm. |
Backfill
layer only |
| Class
C - Cohesive Granular |
A
mixture of clay and aggregate with less than 50%
granular content by weight. The aggregates are graded
with a maximum size of 75mm.
CBR 4% to 7%
|
Backfill
layer only |
| Class
D - Cohesive |
Clay.
Care should be taken to ensure that the material has
the optimum moisture content for compaction. If the
material is dry it can be wetted prior to use.
CBR 2% to 4%
|
Backfill
layer only |
| Granular
Sub-base Type 1 (GSB1) |
Very
similar to that of a Class A material with the
exception that this is quality controlled with regards
to aggregate grading and moisture content.
|
Granular
Roadbase and below, but not used in a Composite road |
Notes:-
Class E Materials:
- Materials that
exhibit high/low moisture content should not be
used.
- Materials lacking
in sufficient grading should not be used.
- Materials that
contain a high percentage of silt should not be
used.
- Any material that
is contaminated with organic or perishable matter,
peat, high fines, frozen materials or particles
greater than 75mm should not be used.
Using any material
described above can lead to the reinstatement failing.
BS 410/EN 10204 Sieve.
20 microns to 125mm
|
