Asphalt-Rubber Binder

D 6114 - 97: A Comprehensive Guide to Asphalt-Rubber Binder Specifications

For engineers and designers involved in advanced pavement construction, understanding the precise material requirements for asphalt-rubber binders is essential. ASTM D 6114 - 97, the "Standard Specification for Asphalt-Rubber Binder," provides an authoritative framework for ensuring the quality and performance of this specialized pavement material. This industry-leading standard is critical for projects demanding enhanced durability and resilience.

What is D 6114 - 97?

ASTM D 6114 - 97 establishes the essential material requirements for asphalt-rubber binder, a composite material formed by blending paving-grade asphalt cement with finely ground recycled tire rubber. Developed by ASTM International, its primary purpose is to ensure that the constituent materials and the resulting binder meet specific quality benchmarks for use in modern pavement construction.

Scope & Purpose

This standard governs the composition, material properties, and testing procedures for asphalt-rubber binder intended for pavement applications. It specifically details the requirements for the asphalt cement and the ground recycled tire rubber, including particle size, purity, and moisture content. The specification also outlines the interaction process and the physical properties the final asphalt-rubber blend must achieve, but it does not define performance-based criteria for asphalt-rubber mixtures themselves.

Who Must Comply?

• • Primary audience: Materials engineers, pavement engineers, civil engineers, quality control inspectors, and laboratory technicians.
• • Industries affected: Construction, Transportation, and Materials Science.
• • Compliance nature: Voluntary, but widely adopted as a recommended practice by agencies and contractors to ensure material quality and consistency.
• • Enforcement: Typically enforced through project specifications and quality assurance programs by transportation agencies and project owners.

Key Requirements Overview

Professionals utilizing ASTM D 6114 - 97 must adhere to several core requirements:

• • The standard mandates specific quality parameters for both the asphalt cement and the ground recycled tire rubber, ensuring compatibility and desired characteristics.
• • Key provisions include stringent limits on moisture content, ferrous and non-ferrous metal particles, and fiber content within the recycled rubber.
• • It requires that the asphalt-rubber binder be an "interacted blend," meaning the rubber has sufficiently swelled within the hot asphalt cement before use.
• • The specification details crucial physical property tests for the final binder, such as apparent viscosity, penetration, softening point, and resilience, to confirm proper blending and modification.
• • A minimum flash point is stipulated to ensure safe handling and application temperatures.

Related Standards & References

ASTM D 6114 - 97 is often used in conjunction with other ASTM standards to ensure comprehensive material quality:

• • ASTM D 946 and ASTM D 3381: These standards specify the base asphalt cements that can be used as a component in the asphalt-rubber binder.
• • ASTM D 2196: This standard is referenced for determining the apparent viscosity of the asphalt-rubber binder, a critical parameter for its workability and pavement performance.
• • ASTM D 5644: This standard outlines methods for determining the particle size distribution of recycled rubber, a key characteristic influencing the binder's properties.

By adhering to this comprehensive specification, engineers can confidently procure