Compaction test documentation is the record that proves filled and embankment material was placed and compacted to specification. Without it, there is no way to certify that a fill was done correctly — and no protection against future settlement claims. The documentation requirements differ by project type, but the core data is always the same. Field density tests follow ASTM D6938 (nuclear gauge) or D1556 (sand cone), with percent compaction calculated against the AASHTO T99 or T180 Proctor maximum dry density.
What must be included in compaction test documentation?
Every compaction test report must include: test location (GPS or station/offset), lift number and material description, test method (nuclear gauge ASTM D6938 or sand cone ASTM D1556), Proctor reference (AASHTO T99 or T180 maximum dry density and optimum moisture), measured in-place dry density and moisture content, calculated percent compaction, pass/fail vs. specification, technician name and certification number, and test date. The Proctor report for the tested material must be on file and referenced.
The minimum data required in a compaction test report is the same regardless of project type. This core data set allows the inspector or geotechnical engineer to verify compliance without any additional information.
| Required Field | Why It Is Required |
|---|---|
| Test location (GPS or station/offset) | Places the test on a map for future reference and dispute resolution |
| Lift number and date | Identifies which construction layer was tested |
| Material description | Confirms the Proctor standard used is valid for this material |
| Test method (ASTM D6938 or D1556) | Identifies the measurement procedure for peer review |
| Proctor reference (max dry density + OMC) | The standard the field test is measured against |
| Measured dry density (pcf) | The actual in-place density from the field test |
| Measured moisture content (%) | Confirms moisture was within range for valid compaction |
| Percent compaction | The compliance number — measured density / Proctor max × 100 |
| Pass/fail vs. specification | Explicit statement of compliance |
| Technician name and certification | Accountability — establishes who performed the test |
| Project Type | Specification Requirement | Standard Test Frequency |
|---|---|---|
| DOT road subgrade | 95% Standard Proctor (T99) or per state spec | 1 per 500 LF per lane per lift |
| DOT aggregate base | 100% Modified Proctor (T180) or per state spec | 1 per 1,000 LF per lane |
| Commercial building pad | 90-95% Standard Proctor per geotech report | 1 per 2,500 sq ft per lift, min. 2 per area |
| Residential pad fill | 90% Standard Proctor (typical) | 1 per 5,000 sq ft per lift |
| Utility trench backfill | 90-95% Standard Proctor, varies by zone | 1 per 200 LF per lift |
| Embankment (earth dam) | 95-98% Modified Proctor or per design | 1 per 5,000 sq ft per lift |
| Solar farm grading | Per geotech report, typically 90% Standard | 1 per 5,000-10,000 sq ft per lift |
| Pipe bedding zone | Varies by pipe type and cover — 90-95% | 1 per 200 LF per lift in pipe zone |
These are typical ranges. Always use the project-specific specification as the governing requirement. When the specification is silent on frequency, use the standard for the most similar project type in the table.
A failing compaction test is a significant construction record event. The documentation for a failing test must include:
Never discard a failing test report and replace it with only the passing retest. Inspectors and owners expect to see both — a record that shows only passing tests is suspicious and may trigger a request for the full testing history.
Sitemark tracks compaction test results by lift and location, flags failures automatically, and links remediation records and retests to the original failing test. The complete testing history for each lift is available in the project record at closeout.
Sitemark logs compaction tests by lift and location, tracks failures and retests, and compiles the testing record by project phase. Start free.
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