Standardization News

A proposed new ASTM International standard will provide an effective low temperature performance graded asphalt binder system using dynamic shear rheometry. WK45135, Test Method for Determining the Low Temperature Rheological Properties of Asphalt Binder Using a Dynamic Shear Rheometer (DSR), is being developed by Subcommittee D04.44 on Rheological Tests, part of ASTM International Committee D04 on Road and Paving Materials

The proposed test method, which is also known as 4-mm DSR, will enable DSR measurements as low as -40˚C, thus allowing for low-temperature specification parameters such as m-value and creep stiffness.

According to Michael Farrar, lead engineer, Western Research Institute, an advantage of the proposed standard is that the test requires only 25 mg of asphalt. This smaller sample size--compared to bending beam rheometer size--and low-temperature capabilities opens the way for new "spin-off" applications of 4-mm DSR, including specification testing of asphalt binder, emulsion residue and crack sealant.

Stacy Glidden, Mathy Construction Co., and a D04 member, says that primary users of the standard will be specifying agencies such as materials laboratories at state departments of transportation, refineries and emulsion and asphalt crack sealant suppliers.

All interested parties are invited to contribute to the ongoing development of WK45135. D04.44 is particularly interested in having asphalt rheology laboratories around the world participate in upcoming round robin testing.

CONTACT Technical Information: Stacy Glidden, Mathy Construction Co. • Onalaska, Wis. • Phone: 608-779-6352 • Email: stacy.glidden@mteservices.com • Michael J. Farrar, Western Research Institute • Laramie, Wyo. • Phone: 307-721-2405 | ASTM Staff: Daniel Smith • Phone: 610-832-9727 | Upcoming Meeting: June 24-26 • June Committee Week • Toronto, Ontario, Canada