Stabilizing Black Cotton Soil as Sub-base – Harhar – Ethiopia, 2008
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AnyWay‘s soil stabilization technology was used in this project to upgrade the very poor in situ black cotton soil to the level required for its incorporation into the sub-base in the pavement structure of the service road at an oil refinery. The loads upon this road are heavy and consist primarily of frequent trucks and service vehicles.
Pavement Structure Design:
- 200 mm local subgrade stabilized with 4% ANSS;
- 150mm base;
- 50 asphalt layer – according to local specifications.
The yard was subjected to the extreme loads shortly after the completion of the work due to needs of the client to operate as soon as possible. The results of a series of deflection testing using Benkelman Beam to assess the performance of the yard after a period of service, had indicated that the pavement structure has little to no deflection. It is performing as expected.
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Process | |
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Soil Characteristics |
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| Percentage Passing #200 | LL | PL | PI | AASHTO Classification | MDD (Kg/m3) | OMC (%) | CBR (%) | Swell (%) |
| 87 |
57
|
39
|
18
|
A-7-5 (21)
|
1596
|
22.50
|
7
|
1.87
|
|
81
|
65
|
40
|
25
|
A-7-5 (25)
|
1570
|
26.00
|
7
|
1.97
|
|
94
|
71
|
42
|
29
|
A-7-5 (36)
|
1602
|
23.00
|
5
|
2.09
|
|
80
|
56
|
39
|
17
|
A-7-5 (18)
|
1627
|
25.00
|
9
|
1.36
|
Savings using ANSS over alternative design
- Cost saving of about 50% on road layers
- Stabilized road immediately usable, surfacing follows as convenient.