Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D4381-22 – Standard Test Method Technical Guide
🏗️ Scope, Apparatus, and Referenced Standards
ASTM D4381-22 specifically determines the sand content by volume of bentonitic slurries used in slurry construction techniques. Modified from API Recommended Practice 13B, it relies on a No. 200 (75 µm) sieve as designated by the alternative system in Practice E11. All observed values must conform to the significant digit rounding rules of Practice D6026. The method applies to construction slurries for concrete walls and drilled piers where sand content is typically below 20 %.
| 🟦 Parameter | 📏 Specification |
|---|---|
| Standard Designation | D4381 − 22 |
| Slurry Type | Bentonitic |
| Sieve Mesh | No. 200 (75 µm) |
| Unit System | SI (Standard) |
| Measurement Range | 0 % to 20 % by volume |
⚙️ Test Procedure and Measurement
The measuring tube of a sand-content set is filled with construction slurry and water to the appropriate marks and vigorously shaken. The mixture is then poured through the No. 200 sieve. The funnel is fitted over the top of the screen, the assembly inverted, and the tip of the funnel inserted into the measuring tube. All retained material is thoroughly washed from the screen back into the tube, allowing the sand volume to be read directly as a percentage.
💡 Quality Assurance: The quality of the result depends on the competence of the personnel and the suitability of the equipment. Agencies are encouraged to follow the minimum requirements of Practice D3740.
📊 Significance and Application Limitations
A high sand content in construction slurry is abrasive for pumps and other construction plant and is adverse to the formation of a proper filter cake needed for excavation stability. While critical for concrete wall and drilled pier applications, this test method is limited to sand contents below 20 %. It is explicitly not suitable for cement-bentonite or soil-bentonite walls where sand content is significantly higher.
⚠️ Important Limitation: This standard does not apply to slurries where the sand content is intentionally greater than 20 %, such as in cement bentonite or soil bentonite walls.
| 📐 Application Type | 🎯 Suitability of D4381-22 |
|---|---|
| Concrete Diaphragm Walls | ✅ Suitable |
| Drilled Piers (Bentonite Slurry) | ✅ Suitable |
| Cement-Bentonite Walls | ❌ Not Suitable (>20 % sand) |
| Soil-Bentonite Walls | ❌ Not Suitable (>20 % sand) |
❓ Frequently Asked Questions
🔍 What is the primary purpose of ASTM D4381-22?
It is used to determine the percent by volume of sand in bentonitic slurries used for slurry construction techniques such as concrete diaphragm walls and drilled shafts.
💡 What is the key apparatus for this test?
The test uses a sand-content set consisting of a measuring tube, a funnel, and a No. 200 (75 µm) sieve to separate the sand from the slurry.
⚡ What does a high sand content indicate?
A high sand content indicates potential abrasion issues for pumps and construction plant, and it can adversely affect the formation of a filter cake required for excavation stability.
📌 What is the maximum sand content this method can measure?
The method is valid for sand contents up to 20 % by volume. It is not intended for mixtures where the sand content is designed to be higher, such as cement-bentonite or soil-bentonite walls.