AASHTO T 370-22 PDF

Full title and description

Standard Method of Test for Measuring Adhesion of Hot-Poured Asphalt Crack Sealant Using Direct Adhesion Tester — a laboratory test method that quantifies the adhesion (peak force and fracture energy) between hot‑poured asphalt crack sealant and aluminum end pieces using a direct adhesion tester at the sealant application temperature.

Abstract

This test method defines specimen preparation, apparatus, test procedure, and calculations used to measure adhesion strength of hot‑poured asphalt crack sealant at application temperature. The test is a fracture‑type tensile test where sealant is confined between two half‑cylindrical aluminum end pieces; load and displacement are recorded so that maximum force (adhesion strength) and area under the load–displacement curve (fracture energy) can be reported. The method replaces the provisional TP 89 designations and aligns with other AASHTO material references for crack sealants.

General information

• Status: Current standard (AASHTO T 370:2022 / active).
• Publication date: 2022 (edition 2022).
• Publisher: American Association of State Highway and Transportation Officials (AASHTO).
• ICS / categories: Road and traffic engineering; materials testing; asphalt materials; pavement maintenance test methods.
• Edition / version: AASHTO T 370-22 (2022).
• Number of pages: 8–9 pages (published AASHTO product sheet lists 9 pages; commercial catalogs list 8 pages).

Scope

Applies to laboratory measurement of the adhesion of hot‑poured asphalt crack sealants using a direct adhesion tester at the application temperature specified by material specifications (for example those referenced in AASHTO M 338 and the associated product provisions). The method covers apparatus, specimen preparation, calibration, test execution, result calculations (peak force and fracture energy), and reporting requirements for quality control, acceptance testing, and comparative evaluation of sealant formulations.

Key topics and requirements

• Purpose: measure adhesion strength and fracture energy of hot‑poured crack sealants.
• Apparatus: direct adhesion tester and matched half‑cylindrical aluminum end pieces; instrumentation to record load and displacement.
• Specimen preparation: confinement of sealant between aluminum end pieces, conditioning to application temperature prior to test.
• Test procedure: controlled tensile loading to failure, with continuous recording of load vs. displacement.
• Calculations: report maximum force (adhesion strength) and energy to failure (area under load–displacement curve); provide units and calculation details.
• Reporting: specimen identification, test temperature, peak load, fracture energy, failure mode description, and any deviations from the procedure.
• Precision and bias: includes guidance on repeatability/reproducibility where available; users should follow specified calibration and verification steps.

Typical use and users

Used by state DOT materials laboratories, pavement maintenance contractors, sealant manufacturers, independent testing labs, and researchers for product development, quality control, specification compliance, and comparative performance evaluation of hot‑poured crack sealants.

Related standards

Commonly referenced alongside AASHTO M 338 (technical specification for hot‑poured crack sealants), relevant AASHTO product provisions and practice documents (e.g., PP 85), and complementary test methods such as AASHTO TP 126 for dynamic tracking/DSR characterization of hot‑poured sealants.

Keywords

crack sealant; hot‑poured asphalt; adhesion; direct adhesion tester; fracture energy; adhesion strength; pavement maintenance; AASHTO T 370; sealant testing.

FAQ

Q: What is this standard?

A: AASHTO T 370-22 is the AASHTO laboratory test method for measuring adhesion of hot‑poured asphalt crack sealant using a direct adhesion tester; it defines apparatus, specimen prep, test execution, calculations, and reporting.

Q: What does it cover?

A: It covers tensile (fracture) testing of sealant bonded to aluminum end pieces at application temperature to determine peak adhesion force and fracture energy, together with calibration, conditioning, and reporting requirements.

Q: Who typically uses it?

A: State DOT and agency materials labs, contractors, manufacturers of hot‑poured crack sealants, third‑party test laboratories, and researchers concerned with product acceptance, QC, and comparative performance.

Q: Is it current or superseded?

A: The 2022 edition (AASHTO T 370:2022) is the current edition and supersedes previous editions (including the 2017 T 370 and the provisional TP 89 designations).

Q: Is it part of a series?

A: It is part of AASHTO’s family of materials test methods for pavement materials and crack sealants; related AASHTO test procedures and provisional methods (for example TP 126 and others) provide complementary rheological and performance assessments.

Q: What are the key keywords?

A: Adhesion, crack sealant, hot‑poured, direct adhesion tester, fracture energy, AASHTO T 370, sealant testing, pavement maintenance.