Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D5581-07 – Standard Test Method Technical Guide
📐 Scope and Apparatus Specifications
This test method, designated ASTM D5581-07a (Reapproved 2021), establishes a procedure for measuring the resistance to plastic flow of cylindrical bituminous paving mixture specimens when loaded on the lateral surface using the Marshall apparatus. It is specifically intended for 6-inch (152.4 mm) diameter specimens to accommodate larger aggregate structures. The method is suitable for mixtures containing asphalt cement and aggregate with a nominal maximum size up to 1½ in. (37.5 mm). The apparatus utilizes a specimen mold assembly composed of steel cylinders with a nominal outside diameter of 6.5 in. (165.1 mm).
📌 Standard Units: As per Section 1.2 of the standard, inch-pound units are regarded as standard for this method, except for reference to sieve sizes (E11) where SI units are standard. Values in parentheses are provided for mathematical conversion only.
⚙️ Significance and Test Workflow
In accordance with Section 3 of the standard, this test method is critical for the laboratory mix design of bituminous mixtures. Specimens are compacted and prepared following the procedures outlined in Practice D6926. The core workflow involves loading the specimen laterally in the Marshall apparatus to determine its maximum load capacity (stability) and the corresponding deformation (flow). Beyond these primary measurements, the method allows for the determination of density and voids properties, which are essential for evaluating mixture performance. Section 3.1 further notes that the test method may be used for cored specimens, though results may differ from laboratory-prepared specimens. The framework of the standard is supported by key references including D6927 for the standard 4-inch test method, C670 for precision statements, and D2493/D2493M for binder viscosity correlations.
📊 Key Measured Properties and Standards Framework
The following tables summarize the critical dimensional specifications and the framework of referenced standards integral to performing the test:
| 📐 Parameter | 📏 Specification from Standard |
|---|---|
| Specimen Diameter | 6 in. |
| Mold Assembly OD | 6.5 in. (165.1 mm) |
| Max Aggregate Size | 1½ in. (37.5 mm) |
| Measured Properties | Stability (Max Load), Flow, Density, Voids |
| Loading Method | Lateral Surface |
| 📋 Key Element | ⚡ Reference / Requirement |
|---|---|
| Specimen Preparation | ASTM D6926 |
| Testing Standard (4 in.) | ASTM D6927 |
| Precision / Bias Guidance | ASTM C670 |
| Binder Viscosity | ASTM D2493/D2493M, AASHTO T 316 |
| Sieve Specifications | ASTM E11 |
⚠️ Important Consideration for 6-inch Specimens: This test method is distinct from the standard 4-inch Marshall test (D6927). The larger 6-inch diameter specimen is specifically required to evaluate mixtures with larger aggregate sizes (up to 1½ in.) to ensure representative compaction and lateral loading during testing. Users must strictly adhere to the 6-inch mold assembly specifications detailed in Section 4 of the standard.
❓ Frequently Asked Questions
🔍 What distinguishes ASTM D5581 from the standard Marshall test (D6927)?
ASTM D5581 specifically covers the resistance to plastic flow test for 6-inch diameter specimens, which allows for testing bituminous mixtures with a nominal maximum aggregate size up to 1½ in. (37.5 mm). The standard 4-inch Marshall test is covered under D6927.
💡 What are the primary measurements obtained from this test?
The test measures the maximum load (stability) and the flow (deformation) of the specimen when loaded laterally in the Marshall apparatus. These values are used in mix design to evaluate the resistance to plastic flow.
📌 Can this method be applied to field cores or only laboratory specimens?
Yes. Section 3.1 of the standard states that the testing section of the method can be used to obtain maximum load and flow for bituminous paving specimens cored from pavements. However, it explicitly notes that results obtained from cored samples may differ from values obtained on laboratory-prepared specimens.
⚡ Which standards govern the preparation of specimens for this test method?
Specimens must be prepared in accordance with ASTM D6926 (Practice for Preparation of Asphalt Mixture Specimens Using Marshall Apparatus). Binder viscosity is managed per D2493/D2493M and AASHTO T 316.