ASTM D4546-21 PDF

Full title and description

ASTM D4546-21 — Standard Test Methods for One‑Dimensional Swell or Collapse of Soils. This standard contains laboratory procedures for measuring one‑dimensional wetting‑induced swell or collapse (hydrocompression) of unsaturated soils and for determining load‑induced compression following wetting‑induced deformation; it includes alternative test methods tailored for reconstituted and intact specimens and for measuring swell pressure and free swell.

Abstract

ASTM D4546-21 specifies three mutually related test methods: Test Method A (wetting of reconstituted specimens — used to simulate compacted fill behavior and to determine swell pressure and free swell), Test Method B (single‑point wetting‑after‑loading of intact specimens to assess inundation‑induced heave or collapse) and Test Method C (loading after wetting to measure load‑induced strains post‑wetting). Results are intended for estimating field heave or settlement and swell pressure when specimens are tested under stresses representative of in‑situ conditions.

General information

• Status: Active (current edition D4546‑21; periodic revision work item initiated).
• Publication date: April 1, 2021 (edition designation “‑21”).
• Publisher: ASTM International.
• ICS / categories: Geotechnical/earthworks; commonly cross‑referenced under ICS 93.020 (Earth works, foundation construction).
• Edition / version: D4546‑21 (current revision published 2021; replaces earlier D4546‑14 and prior versions).
• Number of pages: 10 pages.

Scope

This standard covers laboratory procedures for measuring one‑dimensional wetting‑induced swell or collapse of unsaturated soils and for measuring load‑induced compression after wetting‑induced deformation. It provides methods appropriate for reconstituted specimens (to simulate compacted fills) and for relatively intact samples (to evaluate field heave or collapse), and gives guidance on selecting stresses and inundation/loading sequences that represent field conditions. The methods yield swell strain, swell pressure, and post‑wetting compression values used in geotechnical design and settlement/heave estimates.

Key topics and requirements

• Definitions: free swell, swell pressure, hydrocompression (collapse), and swell/collapse strain.
• Test Method A — wetting of reconstituted specimens to measure free swell, swell pressure, and one‑dimensional swell or collapse behavior.
• Test Method B — single‑point wetting‑after‑loading on intact specimens to determine potential heave or collapse under in‑situ stress conditions.
• Test Method C — loading after wetting to measure load‑induced strains following wetting‑induced deformation.
• Specimen preparation, selection of vertical stress at wetting (often chosen to match in‑situ overburden/structural stress), saturation/inundation procedures, and measurement of axial deformation vs. time.
• Guidance on interpreting laboratory strains and pressures to estimate field heave/settlement and swell pressure; emphasis on reproducing field density, moisture, and loading/wetting sequences because results are sensitive to these conditions.

Typical use and users

Primary users are geotechnical engineers, soils testing laboratories, researchers, and construction quality/control personnel. The standard is used to assess the expansive or collapse potential of natural and compacted soils for foundation, earthworks, pavement, and remedial design, and to provide laboratory input (swell strains, swell pressure, post‑wetting compressibility) for settlement/heave analyses and risk evaluation.

Related standards

D4546 is commonly used alongside other geotechnical ASTM methods such as ASTM D4318 (Atterberg limits), ASTM D698 / D1557 (compaction), ASTM D2487 / D2488 (soil classification), ASTM D2435 (one‑dimensional consolidation), and ASTM D4829 (expansion index) when preparing soils, characterizing index properties, or evaluating compressibility and expansive behavior. Laboratories and accreditation lists that offer D4546 frequently list these companion standards.

Keywords

one‑dimensional swell, collapse, hydrocompression, swell pressure, free swell, wetting‑induced heave, intact specimen, reconstituted specimen, geotechnical laboratory test, ASTM D4546‑21.

FAQ

Q: What is this standard?

A: ASTM D4546‑21 is a set of laboratory test methods for measuring one‑dimensional wetting‑induced swell or collapse of soils and for measuring load‑induced compression after wetting‑induced deformation.

Q: What does it cover?

A: It covers three related test procedures (Tests A, B and C) addressing reconstituted specimens, intact specimens, and loading sequences after wetting; it provides procedures for measuring free swell, swell pressure, swell/collapse strains, and post‑wetting compressibility used to estimate field heave, settlement or swell pressure.

Q: Who typically uses it?

A: Geotechnical consultants, soils testing laboratories, research organizations, and project teams involved in foundation design, earthworks, pavement design, and remediation where soil swelling or collapse is a concern.

Q: Is it current or superseded?

A: The current published edition is D4546‑21 (published April 1, 2021). A work item to revise D4546‑21 was initiated (ASTM WK95337), indicating planned periodic revision activity but not that the 2021 edition has been superseded as of the latest available information.

Q: Is it part of a series?

A: D4546 is part of the suite of ASTM geotechnical standards maintained by Committee D18 (Soil and Rock); it has earlier editions (for example D4546‑14, D4546‑08, etc.) and is commonly used together with other D18 test methods.

Q: What are the key keywords?

A: Swell, collapse, hydrocompression, swell pressure, free swell, heave, settlement, one‑dimensional test, intact specimen, reconstituted specimen, ASTM D4546‑21.