Emulsified Asphalt

AASHTO M 140-08: Standard Specification for Emulsified Asphalt - A Comprehensive Overview

For engineers and project managers involved in road construction and transportation infrastructure, the quality and performance of asphalt binders are paramount. AASHTO M 140-08, the Standard Specification for Emulsified Asphalt, serves as an essential guide for ensuring the reliable application of these critical materials in paving projects. This industry-leading standard provides the foundational requirements for specifying and evaluating emulsified asphalt, directly impacting the durability and longevity of our nation's roadways.

What is AASHTO M 140-08?

AASHTO M 140-08, originating from the American Association of State Highway and Transportation Officials (AASHTO), establishes the comprehensive material requirements and testing procedures for emulsified asphalt. Its primary purpose is to define the quality characteristics that emulsified asphalt binders must meet to be suitable for use in various construction applications, thereby promoting consistency and performance in asphalt pavements.

Scope & Purpose

This standard governs the physical and chemical properties of emulsified asphalt, including its composition, stability, and performance characteristics. It outlines specific tests that must be conducted to verify compliance, such as demulsibility and sieve tests. The scope is primarily focused on the material itself and its acceptance criteria prior to incorporation into pavement mixtures, but it does not dictate specific mix designs or construction practices.

Who Must Comply?

• • Primary Audience: Asphalt Engineers, Pavement Engineers, Materials Engineers, Civil Engineers, and Quality Control Technicians.
• • Industries Affected: Road Construction, Paving, Transportation Infrastructure, and Construction Materials Manufacturing.
• • Compliance Nature: Compliance is typically mandatory for projects utilizing public funds and is often adopted by reference in project specifications.
• • Enforcement: Compliance is generally checked by state Departments of Transportation (DOTs) and their designated quality assurance personnel.

Key Requirements Overview

The standard requires that emulsified asphalt, upon delivery and after proper mixing, remains homogeneous, free from significant separation caused by freezing. Key provisions include stringent limits on the presence of aggregate particles that could interfere with application or performance, as determined by sieve tests. Professionals must ensure that the demulsibility of the emulsified asphalt meets specified thresholds, particularly for samples taken at the point of use where a maximum percentage of 0.30 is acceptable. Furthermore, the standard emphasizes the importance of thorough mixing to achieve a stable emulsion suitable for immediate application, with specific testing timelines stipulated for demulsibility.

Related Standards & References

AASHTO M 140-08 works in conjunction with other proven AASHTO standards. For instance, AASHTO R 5, "Selection and Use of Emulsified Asphalts," provides guidance on selecting the appropriate type of emulsified asphalt for specific pavement applications, referencing M 140-08 for material specifications. Additionally, testing procedures outlined in AASHTO T 40 (equivalent to ASTM D 140) and AASHTO T 59 (equivalent to ASTM D 244) are integral to verifying compliance with the requirements of M 140-08.