Site investigation · Laboratory: compaction & field density
CBR soaked swell & moulding conditions calculator
Swell during soaking, moulding density ratio and moisture ratio for a CBR specimen.
Standard: AS 1289.6.1.1 (swell) · ASTM D1883
Open the live calculator → All site investigation calculators
Inputs in the worked example
The live calculator starts with these values; change any of them and every result, check and diagram updates instantly.
| Input | Value | Unit |
|---|---|---|
| Initial specimen height | 116.4 | mm |
| Dial at start of soak | 2.05 | mm |
| Dial at end of soak | 3.37 | mm |
| Moulded dry density | 1.79 | t/m³ |
| MDD | 1.85 | t/m³ |
| Moulding moisture | 14.8 | % |
| OMC | 15.2 | % |
| Max swell allowed | 1.5 | % |
Worked example — results
| Result | Value | Unit |
|---|---|---|
| Swell | 1.13 | % |
| Density ratio | 96.76 | % |
| Moisture ratio | 97.37 | % |
- ✓ Swell ≤ limit
- ✗ Density ratio within ±1% of target 100%
Method, formulas and assumptions
- Swell = 100*(3.37-2.05)/116.4 = 1.134 %
- Density ratio = 100*1.79/1.85 = 96.757 %
- Moisture ratio = 100*14.8/15.2 = 97.368 %
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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.