Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D6364-06 – Standard Test Method Technical Guide
📐 Scope and Applicability
This standard test method, D6364‑06 (Reapproved 2018), is designed to evaluate the short‑term compressive deformation of geosynthetics or combinations of geosynthetics (i.e., geocomposites) under compressive loading. It explicitly excludes geotextiles, geomembranes, and geosynthetic clay liners. The method serves purely as an index test to verify compressive strength consistency of manufactured products and should not be interpreted as indicative of actual field performance.
Users must recognize that field applications often involve multidirectional compressive loadings not captured by this single‑plane test. The results are not suitable for specifying synthetic drainage systems or assessing long‑term behavior. All values are reported in SI units, with inch‑pound units provided for reference.
⚙️ Test Procedure and Material Sampling
Sampling of geosynthetics for this test must follow Practice D4354. The initial thickness of the test specimen, defined as the gage length, is measured according to Test Method D5199 under a specified compressional force. The specimen is then loaded compressively, and the compressive deformation—the decrease in gage length—is recorded. Compressive strain is calculated as the ratio of this deformation to the original gage length.
The load‑deformation curve is analyzed to identify the yield point, which is the first point where deformation increases without a corresponding load increase. This characterization is crucial for understanding the material’s short‑term compression behavior.
📊 Key Measured Properties and Terminology
Consistent terminology is essential for applying this standard. Definitions are harmonized with Terminology D4439. The following table outlines primary measurements:
| 📏 Term | 🟦 Symbol | 📐 Definition |
|---|---|---|
| Compressive Deformation | [L] | Decrease in gage length produced by compressive load |
| Compressive Strain | [nd] | Ratio of compressive deformation to gage length |
| Gage Length | [L] | Measured thickness under specified compressional force prior to loading |
| Yield Point | — | First point on load‑deformation curve where deformation increases without load increase |
💡 Important Note: This index test is intended for quality control and consistency verification only. It does not predict long‑term performance in field installations.
⚠️ Caution: Do not use the results from this test method as the sole basis for product specification, especially for synthetic drainage systems. Actual field performance depends on factors not covered by this short‑term test.
❓ Frequently Asked Questions
🔍 What is the primary purpose of ASTM D6364?
To evaluate short‑term compressive deformation of geosynthetics as an index test for manufacturing consistency.
💡 Why should this test not be used for field performance?
Because it measures single‑plane compression under idealized conditions, not real‑world multidirectional loads or long‑term effects.
⚡ What units are required by the standard?
SI units are the standard; inch‑pound units are provided for reference only.
📌 Which materials are excluded from this test method?
Geotextiles, geomembranes, and geosynthetic clay liners are not covered under this standard.