|
Acceptable Fill Materials
| Material Location |
Description |
AASHTO
M43
Designation
(1)
|
Compaction/
Density
Requirement |
| D |
Fill material for layer D starts from the
top of layer C to the bottom of flexible pavement or unpaved finish
grade above. Note that pavement sub-base may be part of the D layer. |
Any soil/rock materials, native soils, or per engineer's
plans. Check plans for pavement subgrade requirements. |
N/A |
Prepare per
engineer's plans. Paved installations may have stringent material
and preparation requirements. |
| C |
Fill material for layer C starts
from the embedment stone (B layer) to 18" (457
mm) above the top of the chamber. Note that pavement sub-base may
be part of the C layer. |
Granular well-graded soil/aggregate mixtures, <35%
fines. Most pavement sub-base materials can be used in lieu of this
layer. |
3, 357, 4, 467, 5, 56, 57, 6, 67, 68, 7, 78, 8, 89,
9, 10 |
Begin compaction
after 12" (305
mm) of material over the chambers is reached. Compact additional
layers in 6" (152 mm) lifts to a minimum 95% standard proctor density.
(2) Roller gross vehicle weight
not to
exceed 12,000 lbs. (53 kN). Dynamic force not to exceed 20,000 lbs.
(89
kN). |
| B |
Embedment stone surrounding chambers from the foundation
stone to the C layer above. |
Clean, crushed, angular stone,
nominal size distribution between 3/4" - 2" (19 mm -51 mm) |
3, 357, 4, 457, 5, 56, 57 |
No compaction required. |
| A |
Foundation
stone below chambers from subgrade up to the foot (bottom) of the
chamber. |
Clean, crushed, angular stone, nominal
size distribution between 3/4" - 2" (19 mm - 51 mm) |
3, 357, 4, 457, 5, 56, 57 |
Plate compact or roll to achieve a 95% standard proctor
density.(2) |
Please note:
1. The listed AASHTO designations are for gradations only. The stone
must also be clean, crushed, angular. For example, a specification for
#4
stone would state: "Clean, crushed, angular No. 4 (AASHTO M43) stone."
2. As an alternative to proctor testing and field density measurements in
open grades stone, StormTech compaction requirements are met for 'A' location
materials when placed and compacted in 9" (229) (max) lifts using two
full coverages with an appropriate compactor.
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