The "21" indicates the standard was last revised or reapproved in the year 2021. This test method measures the magnitude of one-dimensional wetting-induced swell or settlement (collapse) of relatively undisturbed or compacted cohesive soils under specific vertical loading conditions. Key Objectives of the Test
If the swell pressure exceeds the allowable bearing capacity or structural weight of a building, engineers must avoid shallow foundations and design deep foundations (such as drilled shafts or piers) that bypass the active zone of moisture fluctuation. astm d454621 pdf
The D4546-21 update is largely a refinement of the 2014 edition. Notable changes include: The "21" indicates the standard was last revised
Now, the most critical part of this article. The keyword is often abused by illegal document sharing sites. Here is the correct, safe, and legal way to obtain this standard. The D4546-21 update is largely a refinement of
This method applies to scenarios where new fill, additional structural loads, or both are placed on ground that has previously experienced wetting-induced heave or settlement. After initial swell or collapse under a given vertical load, additional vertical load increments are applied similarly to a standard consolidation test (per ASTM D2435/D2435M).
The standard is divided into three specific procedures, each tailored to different soil types and engineering needs:
The specimen is inundated with water at a very low seating pressure, allowing it to swell freely or collapse. Once this movement ceases, incremental vertical loads are applied to the sample. This mirrors standard consolidation testing but starts from a saturated, pre-swelled state to determine the soil's modified stress-strain curve. Equipment Required for Testing