The maximum pressure required to maintain a constant volume is defined as the swell pressure.
This data is vital for foundation design, pavement structures, and preventing structural failure.
. This 2021 revision replaced the previous D4546-14 version with minor editorial updates and refined unit measurement statements. 🛠️ Key Test Methods
Designing retaining walls, basement slabs, and deep foundations that must resist lifting forces. 4. Laboratory Apparatus and Setup astm d454621 pdf
| Standard | Purpose | |----------|---------| | ASTM D2435/D2435M | One‑dimensional consolidation properties (incremental loading) | | ASTM D4829 | Expansion index of soils (a simpler, more rapid test) | | ASTM D1587/D1587M | Thin‑walled tube sampling of fine‑grained soils for geotechnical purposes | | ASTM D2216 | Laboratory determination of water (moisture) content |
The "21" in D4546-21 signifies the revision year 2021. It refined the procedures from previous versions (like 96 or 2014) to better address:
ASTM D4546-21 is the official standard published by ASTM International titled “Standard Test Methods for One-Dimensional Swell or Collapse of Cohesive Soils” . The maximum pressure required to maintain a constant
Executing an ASTM D4546-21 test requires specialized geotechnical laboratory equipment:
An expansive clay site in Texas required a foundation design to prevent slab heave. Using ASTM D4546-21 Method B on intact specimens from various depths, engineers measured swell pressure and free swell magnitudes. These data guided the design of drilled pier foundations, avoiding typical repair costs of $10,000–$15,000 per residential slab.
Soil is tested in a rigid, laterally confined ring; actual field conditions may involve 3D strains. 📑 Common Report Deliverables This 2021 revision replaced the previous D4546-14 version
Depending on the chosen method (B or C), predetermined vertical increments of stress are applied to the dry sample.
Evaluates intact samples obtained from natural deposits or existing compacted fills.
After finding this pressure, the specimen is often unloaded in increments to measure its rebound characteristics. 4. Laboratory Apparatus and Setup