ASTM D4318 – Atterberg Limits

Introduction

The Atterberg Limits test is a core part of soil classification in geotechnical engineering and construction materials testing. Almost every project involving earthwork relies on accurate Liquid Limit (LL), Plastic Limit (PL), and Plasticity Index (PI) values to determine soil behavior, shrink swell potential, compressibility, and suitability for use as engineered fill.

ASTM D4318 defines the test procedures for LL and PL, but many geotechnical firms still use handwritten worksheets, spreadsheets, and disconnected workflows that slow down reporting and introduce inconsistencies.

Aldoa provides a complete digital workflow for ASTM D4318. Field data flows directly into the lab, LL and PL values are calculated automatically, PI is generated instantly, and results populate seamlessly into boring logs or geotechnical reports. This improves accuracy, consistency, and turnaround.

This article explains ASTM D4318, highlights common workflow challenges, and shows how Aldoa modernizes the full Atterberg Limits process.

What ASTM D4318 Atterberg Limits Measures

ASTM D4318 defines three key properties:

1. Liquid Limit (LL)

The moisture content at which a soil transitions from a plastic to a liquid state.

2. Plastic Limit (PL)

The moisture content at which a soil begins to crumble when rolled into threads.

3. Plasticity Index (PI)

PI is one of the most important indicators of soil behavior. High PI soils tend to be expansive, compressible, and moisture sensitive, while low PI soils behave more like non plastic or granular materials.

These values directly influence:

• Site grading decisions
• Foundation recommendations
• Pavement design
• Shrink swell analyses
• Material suitability assessments

Given their importance, labs need reliable workflows with consistent documentation.

Common Challenges with Traditional LL and PL Workflows

Traditional approaches often involve:

• Handwritten worksheets near ovens
• Spreadsheets with different calculation formulas
• Photos stored on personal devices
• Missing sample IDs
• Manual transfer of results into boring logs

These issues lead to:

Inconsistent test documentation

Different technicians use different worksheets.

Calculation errors

Spreadsheets with outdated formulas or incorrect cell references create discrepancies.

Delayed lab processing

Lab technicians may not know which samples are coming from the field until they arrive.

Disconnected reporting

Results must be manually typed into boring logs or reports.

Poor traceability

Auditors often struggle to match LL and PL values to original samples. Aldoa solves these issues with a connected, standardized workflow.

Aldoa’s End to End ASTM D4318 Workflow

Aldoa centralizes sample creation, lab work, calculations, and reporting.

Step One: Field Sample Creation

Field technicians create soil samples directly inside Aldoa. They capture:

• GPS location
• Depth
• Sample type
• Photos
• Soil descriptions
• Moisture observations

This ensures the lab receives complete and accurate data.

Sample IDs follow the project structure and automatically link to boring logs.

Step Two: Lab Receives Sample Data

Lab staff see incoming samples instantly. They can sort by:

• Project
• Required tests
• Priority
• Technician assignment
• This helps supervisors balance workloads and schedule LL and PL testing efficiently.

Step Three: Digital LL and PL Worksheets

Aldoa provides a standardized digital ASTM D4318 worksheet. Technicians enter:

• Container weights
• Wet soil weights
• Dry soil weights
• Trial results
• Liquid Limit readings (fall cone or Casagrande device)
• Plastic Limit thread roll results

All calculations update automatically.

Aldoa automatically computes:

• Moisture content
• Average PL
• Average LL
• PI

This eliminates spreadsheet variability and ensures consistency.

Step Four: Technician Review and Supervisor Approval

Supervisors review:

• Moisture calculations
• Trial consistency
• Technician notes
• Plasticity Index
• Any anomalies

Aldoa stores all edits, entries, and approvals for QA and traceability.

Step Five: Automatic Reporting and Boring Log Integration

Aldoa generates:

• Atterberg Limits results
• LL, PL, and PI summaries
• Soil classification
• Graphs or tables

Results flow directly into Aldoa’s boring logs and geotechnical outputs. There is no manual transfer.

Key Benefits of Using Aldoa for Atterberg Limits Testing

• Standardized Digital Forms: Everyone uses the same worksheet.
• Reduced Errors: Automatic moisture and PI calculations improve accuracy.
• Better Traceability: Clear audit trails support DOT and QA requirements.
• Faster Reporting: Results update in real time across the project.
• Integration with Boring Logs: LL and PL values appear automatically in logs and summary tables.
• Field and Lab Connected: No more lost sample tickets or incomplete information.

Why Aldoa Outperforms Spreadsheets and Legacy Systems

Compared to spreadsheets

Aldoa removes version control issues and formula errors.

Compared to paper forms

Aldoa eliminates lost notes and transcription mistakes.

Compared to MetaField

Aldoa offers a more intuitive geotechnical workflow with direct boring log integration.

Compared to SpectraQEST

Aldoa is easier to adopt and simpler for lab technicians.

Conclusion

Atterberg Limits testing should be reliable, fast, and consistent. Aldoa provides a modern solution that connects field sampling, lab testing, PI calculation, and boring log reporting in one system.

For geotechnical firms that want cleaner workflows and faster turnaround, Aldoa delivers a complete ASTM D4318 solution.