Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D546-24 – Standard Test Method Technical Guide
📐 Scope and Significance
This test method, designated D546‑24 and adopted by AASHTO as T 37, covers the standardized procedure for the sieve analysis of mineral fillers used in asphalt paving mixtures. As stated in the standard, its primary significance is to determine compliance of mineral filler materials with the grading requirements of Specification D242/D242M. The method relies on test sieves conforming to Specification E11, where SI unit values for wire cloth openings are considered standard. It is important to note that the values stated in either SI units or inch‑pound units are to be regarded separately as standard, as combining the two systems may result in non-conformance with the standard.
| 🟦 Element | 📏 Specification / Requirement |
|---|---|
| Standard Designation | D546 – 24 |
| Equivalent Standard | AASHTO T 37 |
| Material Scope | Mineral Filler for Asphalt Paving Mixtures |
| Primary Specification Referenced | D242/D242M |
⚙️ Test Procedure and Apparatus Requirements
A representative sample of the mineral filler must be obtained and reduced in accordance with Practice C702/C702M for reducing samples of aggregate to testing size. The material is dried to a constant mass in an oven capable of maintaining a temperature of 110 ± 5 °C. A typical test specimen mass for this analysis is 100 g, ensuring proper sieving dynamics without overloading the sieve surfaces.
The nested sieve stack typically includes the 300‑µm (No. 50), 150‑µm (No. 100), and 75‑µm (No. 200) sieves placed above a bottom pan. The sample is poured onto the top sieve and subjected to mechanical agitation for a sufficient duration to achieve complete particle separation. The mass retained on each sieve is then weighed using a balance or scale conforming to Guide D4753, with a readability of 0.01 g recommended for this level of precision.
⚠️ Agglomeration Hazard: Mineral fillers are very fine materials. If the sample contains significant fines or clay coatings that cause agglomeration, the dry sieving method may produce inaccurate results. In such cases, the standard directs the user to the wet method described in Test Method C786/C786M to effectively wash fines through the sieves.
💡 Sieve Maintenance: Per Specification E11, all sieves must be routinely inspected for wear and distortion. A thorough cleaning with a soft brush is essential after each test to prevent the blinding of mesh openings and to ensure the validity of subsequent analyses.
| 🟦 Apparatus | 🎯 Requirement |
|---|---|
| Sieves | 300 µm (No. 50), 150 µm (No. 100), 75 µm (No. 200) conforming to E11 |
| Balance | Conforming to D4753 (readability of 0.01 g recommended) |
| Oven | Thermostatically controlled, 110 ± 5 °C |
| Mechanical Shaker | Provides uniform sieving action |
📊 Reporting and Key Data
The final report must clearly document the cumulative percentage passing each sieve size. The percentage passing is calculated by subtracting the cumulative mass retained from the original dry mass, then dividing by the original dry mass. For a mineral filler to meet the requirements of Specification D242/D242M, specific particle size distribution criteria must be satisfied. The standard terminology used in the document is defined in Terminology D8, and the precision and bias of the method are addressed in accordance with Practice C670.
❓ Frequently Asked Questions
🔍 What is the primary purpose of ASTM D546‑24?
This test method is used to determine the particle size distribution (gradation) of mineral filler for asphalt paving mixtures, specifically to verify compliance with the grading requirements of Specification D242/D242M.
💡 Which sieves are required for this test?
The method requires the use of the 300‑µm (No. 50), 150‑µm (No. 100), and 75‑µm (No. 200) sieves, all of which must conform to the wire cloth specifications in Specification E11.
⚡ When is the wet method (C786/C786M) preferred over the dry method?
If the mineral filler contains significant fines that are prone to agglomeration or if clay contamination is suspected, the wet method is preferred to ensure accurate particle dispersion during the sieving process.
📌 How does D546‑24 relate to AASHTO T 37?
ASTM D546‑24 is technically equivalent to AASHTO Standard T 37. Both standards address the same test method for the sieve analysis of mineral filler and are used interchangeably by agencies and laboratories.