How the Field Density Test (Sand Cone) works
Sand in hole = total sand used − cone and base correction. Hole volume = sand in hole ÷ calibrated sand density. Wet density = wet soil mass ÷ hole volume. Dry density = wet density ÷ (1 + moisture content ÷ 100). Compaction % = field dry density ÷ laboratory maximum dry density (MDD) × 100.
How to use this calculator
- Calibrate your sand and cone correction using ASTM D1556 / AASHTO T191.
- Enter total sand used, cone correction and calibrated sand density.
- Enter the wet soil mass from the hole and its moisture content.
- Enter the laboratory MDD from the specified Proctor test and your project's required compaction.
- Read dry density, compaction percentage and the pass/fail result, then print the report.
Typical uses
Checking compaction of backfill, subgrade, embankment and road layers against the compaction percentage stated in your project specification.
Assumptions & limitations
Use calibrated apparatus and the specified laboratory Proctor result. This sheet supports your field record; acceptance remains subject to the project specification, approved ITP and the Engineer's review.
Frequently asked questions
- Does the calculator assume 95% compaction?
- No. You enter the required compaction yourself from the project specification or approved ITP. The sand cone method itself sets no universal acceptance limit.
- Which standard does it follow?
- The calculation follows the sand cone / sand replacement relationships in ASTM D1556/D1556M and AASHTO T191, with laboratory MDD from ASTM D698 or D1557 as specified.
- Can I print the result?
- Yes. Print or save the calculation sheet as PDF with project, location, layer and date references.
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