AASHTO R 30-24 PDF

Full title and description

St AASHTO R 30-24 — Standard Practice for Mixture Conditioning of Hot‑Mix Asphalt (HMA). This recommended practice describes laboratory conditioning procedures used to simulate short‑term and long‑term aging of hot‑mix asphalt for volumetric mix design and mechanical property/performance testing, including procedures for loose‑mix (pre‑compaction) and compacted specimen conditioning.

Abstract

AASHTO R 30-24 provides standardized oven‑conditioning procedures to reproduce, in the laboratory, the effects of plant production, storage/transport, and in‑service oxidative aging on asphalt mixtures. The practice defines short‑term oven aging (STOA) protocols used prior to compaction or mechanical testing and describes long‑term oven aging (LTOA) options intended to represent multi‑year field aging. The 2024 revision aligns STOA/LTOA procedures with recent NCHRP research recommendations and is referenced by related AASHTO conditioning practices.

General information

• Status: Active (current AASHTO recommended practice; 2024 revision identified as R 30-24).
• Publication date: 2024 (designation suffix “-24” indicates the 2024 revision).
• Publisher: American Association of State Highway and Transportation Officials (AASHTO).
• ICS / categories: Road and bridge engineering; bituminous mixtures and asphalt / laboratory testing (road materials and testing categories).
• Edition / version: R 30-24 (revision following the previously published R 30‑02 / R 30 editions).
• Number of pages: Previous published edition (R 30‑02 / legacy document) was a short practice (≈5 pages); the exact page count for R 30‑24 is subject to the AASHTO published file.

Scope

This practice establishes laboratory conditioning procedures to simulate the thermal and oxidative history of hot‑mix asphalt from production through multiple years in service. It covers: (a) conditioning of loose mix for volumetric mix design, (b) short‑term conditioning of loose mix prior to mechanical property testing, and (c) long‑term conditioning approaches for assessing longer‑term stiffness, fatigue, and cracking behavior. The scope also clarifies when STOA is required (mix design vs. production QA) and references complementary AASHTO and NCHRP guidance for climate‑ or application‑specific long‑term conditioning.

Key topics and requirements

• Definitions and purpose of conditioning: short‑term vs. long‑term aging and their role in mix design and performance testing.
• Short‑term oven aging (STOA) procedures: loose mix conditioning prior to compaction or testing (historically 4 h at 135°C for mechanical testing or 2 h at compaction temperature for volumetric mix design; 2024 revisions align STOA times/temperatures with NCHRP recommendations for HMA and WMA).
• Long‑term oven aging (LTOA) procedures: compacted or loose‑mix options intended to simulate multiple years of field aging (traditional method: 5 days at 85°C on compacted specimens; alternative loose‑mix LTOA methods and climate‑dependent approaches are discussed and referenced).
• Specimen preparation and handling: pans, layer thickness, stirring intervals, cooling/conditioning schedules, and compaction considerations for gyratory or slab/coring methods.
• Application notes: when STOA is required (mix design vs. production QA), guidance for modified binders, warm‑mix technologies, high RAP/RAS contents, and considerations where alternate conditioning protocols may be more appropriate.

Typical use and users

AASHTO R 30-24 is used by state Departments of Transportation, materials and pavement laboratories, consulting engineers, hot‑mix asphalt producers, research organizations (NCHRP/NCAT), and contractors. Typical applications include mix design verification, performance testing (dynamic modulus, fatigue, rutting, fracture), quality assurance of plant mixes, and research into aging effects and mitigation strategies.

Related standards

Closely related AASHTO standards and documents include AASHTO test methods referenced for specimen preparation and testing (for example, T 312, various T‑series mechanical tests), AASHTO R 121 (long‑term laboratory conditioning guidance referenced in 2024), and NCHRP research reports (NCHRP 9‑52, 9‑54) that informed the 2024 conditioning updates. Agencies may also reference ASTM and national practice documents for complementary procedures.

Keywords

short‑term oven aging; long‑term oven aging; STOA; LTOA; mixture conditioning; hot‑mix asphalt; HMA; aging simulation; laboratory conditioning; pavement materials; AASHTO R 30-24.

FAQ

Q: What is this standard?

A: AASHTO R 30-24 is the AASHTO recommended practice describing laboratory procedures to condition hot‑mix asphalt (HMA) to simulate production and in‑service aging for mix design and performance testing.

Q: What does it cover?

A: It covers short‑term and long‑term conditioning procedures (loose‑mix and compacted specimen methods), required oven temperatures and durations for common conditioning protocols, specimen handling and preparation notes, and application guidance for mix design, QA, and performance testing.

Q: Who typically uses it?

A: State DOT materials labs, commercial testing laboratories, mix designers, contractors, and researchers rely on R 30 for consistent laboratory aging practices used in design, acceptance, and research.

Q: Is it current or superseded?

A: R 30-24 is presented as the 2024 revision (current) and follows earlier published editions of R 30 (for example, the R 30 legacy practice available through AASHTO webstore). Agencies should verify the edition they require; R 30-24 aligns with and is referenced by related 2024 AASHTO conditioning guidance (for example, R 121-24).

Q: Is it part of a series?

A: Yes — R 30 is part of AASHTO’s recommended practices and is used together with AASHTO test methods (T‑series for specimen prep and mechanical testing) and related AASHTO recommended practices and NCHRP guidance documents.

Q: What are the key keywords?

A: Short‑term oven aging (STOA), long‑term oven aging (LTOA), mixture conditioning, hot‑mix asphalt (HMA), laboratory aging, pavement materials, AASHTO R 30-24.