ASTM D8044-23 PDF

Full title and description

Standard Test Method for Evaluation of Asphalt Mixture Cracking Resistance Using the Semi‑Circular Bend Test (SCB) at Intermediate Temperatures — a laboratory procedure that defines sample preparation, SCB specimen geometry and notch, monotonic testing, and calculation of the critical strain energy release rate (Jc) and related parameters used to compare cracking resistance of asphalt mixtures at intermediate temperatures.

Abstract

This test method specifies the semi‑circular bend (SCB) configuration and test procedure for measuring cracking resistance of asphalt mixtures at intermediate temperatures. The method defines the determination of the critical strain energy release rate parameter (Jc) and other load–displacement derived parameters for ranking mixtures prepared with different binders and aggregates. The standard is intended for research and informational use because a full precision and bias statement has not been developed.

General information

• Status: Active.
• Publication date: May 15, 2023.
• Publisher: ASTM International.
• ICS / categories: Road construction materials (ICS 93.080.20).
• Edition / version: Designation D8044‑23 (revises D8044‑16).
• Number of pages: 7 pages.

Scope

This test method covers preparation, testing, and measurement procedures for laboratory‑prepared or pavement‑core asphalt mixture samples using the semi‑circular bend (SCB) specimen geometry with a vertical notch. It describes the determination of the critical strain energy release rate (Jc) and other parameters derived from the load‑displacement curve to rank mixture cracking resistance at intermediate temperatures. SI units are the standard. The method is stated to be for research and informational purposes and not for material acceptance because a complete precision and bias statement has not been developed.

Key topics and requirements

• SCB specimen geometry: half‑disk (semi‑circular) specimens with a machined or sawed notch aligned with the loading axis.
• Test procedure: monotonic loading of SCB specimens at intermediate temperatures to generate load‑displacement curves.
• Primary parameter: critical strain energy release rate (Jc) as an engineering/performance indicator for intermediate‑temperature cracking resistance.
• Additional outputs: fracture‑related parameters derived from load‑displacement behavior for mixture ranking.
• Units and reporting: SI units required; notes and footnotes provide explanatory material but are not requirements.
• Limitations: method currently lacks a complete precision and bias statement — intended for research/informational use rather than acceptance testing.

Typical use and users

Used by pavement researchers, highway agencies, materials laboratories, contractors, and consultants for mixture characterization, mix design evaluation, and comparative research of cracking resistance at intermediate temperatures. Typical applications include laboratory ranking of candidate mixtures, binder‑aggregate evaluations, and performance‑focused research rather than formal contractual acceptance testing.

Related standards

Referenced or related test methods and practices used for asphalt mixture fracture/cracking evaluation and context include prior edition ASTM D8044‑16 (revised), AASHTO performance test procedures for fracture/cracking (examples in the pavement testing family), and European methods such as EN 12697‑44; users often consult companion AASHTO or regional standards and test practices when placing SCB results in a broader performance framework.

Keywords

asphalt, cracking resistance, semi‑circular bend, SCB, critical strain energy release rate, Jc, intermediate temperature, fracture toughness, pavement materials, mixture evaluation.

FAQ

Q: What is this standard?

A: ASTM D8044‑23 is a test method that defines the semi‑circular bend (SCB) test and calculations for evaluating asphalt mixture cracking resistance at intermediate temperatures, producing the Jc parameter and related fracture metrics.

Q: What does it cover?

A: It covers specimen preparation (SCB half‑disk with a notch), monotonic loading test procedures at intermediate temperatures, data recording (load vs. displacement), and calculation of Jc and other load‑displacement derived parameters used to rank mixtures. It notes that SI units are standard and that the method is for research/informational purposes pending a full precision/bias statement.

Q: Who typically uses it?

A: Pavement researchers, state DOT and highway agency laboratories, university labs, materials consultants, and contractors performing performance‑oriented mixture evaluations and comparative studies.

Q: Is it current or superseded?

A: Current as of the designation D8044‑23 (published May 15, 2023); it revises the earlier D8044‑16 edition. Users should confirm status with ASTM or their national standards provider for updates after this publication.

Q: Is it part of a series?

A: It is produced under ASTM Committee D04 (Road and Paving Materials) and sits alongside related ASTM and AASHTO test methods and guides addressing asphalt mixture characterization and fracture/cracking evaluation; it directly revises an earlier D8044 edition.

Q: What are the key keywords?

A: Key keywords include SCB, semi‑circular bend, Jc, cracking resistance, asphalt mixture, intermediate temperature, fracture energy, strain energy release rate.