Site investigation · Laboratory: compaction & field density
Relative compaction & moisture variation calculator
Density ratio and moisture variation from field and laboratory results against a specification window.
Standard: AS 1289.5.4.1 · AS 3798
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 |
|---|---|---|
| Field dry density | 1.79 | t/m³ |
| Field moisture | 16.4 | % |
| Lab MDD | 1.84 | t/m³ |
| Lab OMC | 15 | % |
| Min density ratio | 95 | % |
| Moisture variation lower limit | -2 | % |
| Moisture variation upper limit | 1 | % |
Worked example — results
| Result | Value | Unit |
|---|---|---|
| Density ratio | 97.28 | % |
| Moisture variation w − OMC | 1.40 | % |
| Moisture ratio | 109.3 | % |
- ✓ Density ratio ≥ min
- ✗ Moisture variation within window
Method, formulas and assumptions
- Density ratio = 100*1.79/1.84 = 97.283 %
- Moisture variation w − OMC = 16.4-15 = 1.4 %
- Moisture ratio = 100*16.4/15 = 109.33 %
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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.