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D5711-03 – Standard Test Method Technical Guide
The ASTM D5711-03 standard provides a definitive test method for quantifying the material that adheres to the surface of coarse aggregate particles. This test is vital for quality control in hot mix asphalt (HMA), seal coats, surface treatments, and portland cement concrete, ensuring that aggregate sources meet specified cleanliness requirements. By precisely measuring particles smaller than 75-µm (No. 200) that stick to larger aggregate, engineers can make informed decisions regarding material acceptance and processing needs.
⚙️ Essential Apparatus and Standard Sizes
Proper execution of this test method requires specific equipment conforming to ASTM E 11. The key apparatus includes a balance readable to 0.1 g with an accuracy of 0.1 g or 0.1% of the test load, and a mechanical sieve shaker imparting vertical or lateral motion. The following sieves are fundamental to the procedure:
| 🟦 Sieve Designation (Standard) | 📏 Sieve Designation (Alternate) | 🎯 Function in Test |
|---|---|---|
| 2.36 mm | No. 8 | Primary separation of coarse aggregate fraction |
| 75 μm | No. 200 | Washing sieve to determine adherent fines |
| 4.75 mm | No. 4 | Optional intermediate sizing |
Additional sieves (37.5-mm, 25-mm, 19-mm, 12.5-mm, 9.5-mm) are available for segregating the coarse aggregate into specific size fractions as required by project specifications.
Note: This test method is modeled after Federal Land Highways T 512-94. The values stated in SI units are to be regarded as the standard.
📐 Test Procedure and Calculation Methodology
The procedure strictly adheres to the standard’s summary in Section 4. The sample is first dried to a constant mass and separated over a 2.36-mm (No. 8) sieve. The fraction retained on this sieve is designated the coarse aggregate and its mass is recorded as the original mass. This coarse material is then washed thoroughly over a 75-µm (No. 200) sieve until the wash water runs clear, removing any loose or adherent fines. The remaining coarse aggregate is dried and weighed again. The adherent coating percentage is calculated using the formula:
Adherent Coating (%) = [(Original Mass – Final Mass) / Original Mass] × 100
The table below demonstrates a typical calculation as outlined by the standard data requirements:
| 📐 Sample ID | ⚡ Initial Mass (g) | 📏 Final Mass (g) | 🎯 % Adherent Coating |
|---|---|---|---|
| Sample A | 5000.0 | 4952.5 | 0.95% |
| Sample B | 5000.0 | 4890.0 | 2.20% |
Pro Tip: When washing the coarse aggregate, avoid excessive water pressure or mechanical abrasion that might break down weak aggregate particles. The goal is to remove *adherent coating* (fines < 75 µm), not to degrade the coarse aggregate itself.
📊 Significance in Quality Control
As stated in Section 5 and Section 1, this test assigns a measurable value to the amount of fine material adhering to the aggregate. This information is used for the preliminary investigation of aggregate sources, controlling material in hot mix asphalt (HMA), seal coats, cover coats, surface treatments, cold mix asphalt, and portland cement concrete. An excess of adherent coating can prevent proper binder-aggregate bonding, leading to stripping or raveling in pavements. The test is therefore critical for both source approval and ongoing production control.
❓ Frequently Asked Questions
🔍 What is the precise definition of “adherent coating” in this standard?
According to Section 3.1.1, adherent coating refers to fine particles smaller than 75-µm (No. 200) that stick (adhere) to the coarse aggregate particles. It specifically excludes larger fines that are simply loose in the sample.
💡 How does this test differ from a standard aggregate wash test (ASTM C117)?
While both use a 75-µm sieve, ASTM C117 determines the total amount of material finer than 75-µm in the entire aggregate sample. D5711-03 specifically focuses on the material that remains adherent to coarse aggregate (2.36-mm and larger) after the sample has been separated. It targets the coating that might interfere with binder adhesion.
⚡ What are the exact balance requirements for D5711-03?
Section 6.1 specifies that the balance or scale must be readable to 0.1 g and accurate to 0.1 g or 0.1% of the test load, whichever is greater, at any point within the range of use. This high degree of accuracy is essential for calculating small percentages of coating on large sample masses.
📌 What types of construction projects rely on D5711-03 results?
This standard is vital for any project using coarse aggregates, specifically called out for Hot Mix Asphalt (HMA) pavements, seal coats, cover coats, surface treatments, cold mix asphalt, and portland cement concrete as listed in Section 1.1.2. It serves as a control test at the source of supply.