ASTM D4648/D4648M-24a PDF

Full title and description

St ASTM D4648/D4648M-24a — Standard Test Methods for Laboratory Miniature Vane Shear Test for Saturated Fine‑Grained Soil. Provides procedures for performing laboratory miniature vane shear tests (both torque‑spring and motorized torque transducer methods) to determine undrained shear strength of saturated fine‑grained soils (clays and clayey silts).

Abstract

These test methods describe laboratory miniature vane shear testing for saturated fine‑grained soils, covering a range of very soft to stiff clays with typical undrained shear strengths in the lower kPa range (commonly used where strengths are below about 100 kPa). The standard defines two principal procedures (Method A: calibrated torque springs; Method B: electrical torque transducer with motorized device), guidance on sample preparation and interpretation, and reporting conventions consistent with established geotechnical practices.

General information

• Status: Active (current edition designated D4648/D4648M-24a).
• Publication date: October 15, 2024 (edition identified as -24a).
• Publisher: ASTM International (American Society for Testing and Materials).
• ICS / categories: 93.020 — Earth works; excavations; foundation construction; underground works (geotechnical testing).
• Edition / version: D4648/D4648M-24a (current revision).
• Number of pages: ~8 pages (publisher listing for this edition).

Scope

The standard covers laboratory miniature vane shear tests for saturated fine‑grained soils used to determine undrained shear strength and sensitivity. It applies primarily to clayey soils where vane failure approximates a cylindrical shear surface and where undrained behavior is expected; it is not intended for cohesionless or highly permeable soils where drainage during testing invalidates results. Procedures for both torque‑spring and instrumented motorized devices are included, together with reporting requirements and guidance on significant‑digit conventions.

Key topics and requirements

• Two test procedures: Method A (calibrated torque spring units) and Method B (electrical torque transducer with motorized miniature vane).
• Applicable soil types: saturated fine‑grained clays and clayey silts; not recommended for coarse, sandy, or highly permeable soils.
• Typical strength range guidance (very soft to stiff clays; commonly used where undrained shear strengths are low—order of tens of kPa up to ~100 kPa).
• Sample handling, insertion and rotation rates, calculation of torque to shear strength, and rounding/significant‑digit rules (referencing Practice D6026).
• Reporting requirements: units (SI and inch‑pound presented separately), test conditions, equipment type and calibration, and any corrections or assumptions used in strength interpretation.

Typical use and users

Used by geotechnical laboratories, research groups, and consulting engineers for index and small‑sample strength characterization of saturated fine‑grained soils. Typical applications include site investigation follow‑up tests, research on soil anisotropy and sensitivity, verification of undrained shear strength for design or comparison with field vane, cone penetrometer, or triaxial results. The miniature laboratory vane is especially useful when available samples are small or when investigating anisotropy on intact specimens.

Related standards

Standards commonly referenced with D4648/D4648M include: Practice D6026 (significant digits and rounding in geotechnical data), Standard Test Method D2573/D2573M (field vane shear test for saturated fine‑grained soils), and other geotechnical test methods used for comparison such as D2166 (unconfined compression), D2850 (unconsolidated undrained triaxial), and D5778 (cone penetration) when evaluating or correlating strength data.

Keywords

miniature vane shear; laboratory vane; saturated fine‑grained soil; undrained shear strength; clays; torque transducer; torque spring; sensitivity; geotechnical testing.

FAQ

Q: What is this standard?

A: ASTM D4648/D4648M-24a is the ASTM standard that specifies laboratory miniature vane shear test methods for determining the undrained shear strength of saturated fine‑grained soils.

Q: What does it cover?

A: It covers two laboratory procedures (calibrated torque spring and motorized torque transducer), specimen preparation and handling, test execution (insertion and rotation rates), calculation of torque to undrained shear strength, and reporting conventions including units and significant‑digit rules. It also describes applicability limits (not for sandy or highly permeable soils).

Q: Who typically uses it?

A: Geotechnical laboratories, consulting geotechnical engineers, researchers studying clay behavior or sensitivity, and agencies performing laboratory strength characterization where sample size or anisotropy assessment makes the miniature vane useful.

Q: Is it current or superseded?

A: The edition D4648/D4648M-24a is listed as the current/active edition (published October 15, 2024). Prior editions (for example 2016, 2013) have been superseded by the 24a revision. Users should confirm any later revisions through ASTM.

Q: Is it part of a series?

A: It is part of ASTM Committee D18 geotechnical test methods and is used alongside related vane and strength test standards (e.g., D2573 field vane, D2166 unconfined compression, D2850 triaxial methods) and practices such as D6026 for data reporting.

Q: What are the key keywords?

A: Miniature vane, laboratory vane, saturated fine‑grained soil, undrained shear strength, clays, torque transducer, torque spring, sensitivity, geotechnical testing.