Journal Published Online: 06 July 2015
Volume 44, Issue 1

Use of the Multiple Stress Creep Recovery (MSCR) Test Method to Characterize Polymer-Modified Asphalt Binders

CODEN: JTEVAB

Abstract

Use of polymer-modified binder has become much more important in recent years to enhance the durability and strength of asphalt concrete (AC) pavements in order to sustain higher traffic volumes, heavier loads, and extreme weather conditions. Unlike neat (unmodified) asphalt binders, polymer-modified binders are sensitive to the applied stress levels and show a nonlinear response in rutting factor and phase angle. The widely used dynamic shear rheometer (DSR) test (AASHTO T315) is not sufficient to capture viscoelastic properties of polymer modified-asphalt binders. Thus, state transportation agencies often need to conduct additional expensive and time consuming “PG Plus” tests (e.g., elastic recovery (ER), force ductility, toughness, and tenacity) for characterizing polymer-modified binders. Multiple stress creep recovery (MSCR), a recently introduced test method (AASHTO TP 70) for measuring high temperature properties of an asphalt binder, is expected to replace the existing AASHTO T315 for short-term aged binder. In the current study, MSCR and Superpave tests were conducted on three commonly used performance grade (PG) binders (PG 64-22, PG 70-28, and PG 76-28) from 12 different sources throughout Oklahoma. Based on expected traffic loads and service temperatures, the tested binder samples were graded in accordance with the MSCR grading system. The non-recoverable creep compliance (Jnr) and MSCR % recovery values obtained from the MSCR tests were then analyzed using the polymer curve and quadrant methods to assess the feasibility of the adoption of the MSCR test method for conditions prevailing in Oklahoma. Findings of this study reveal that the MSCR test method can be used to characterize polymer-modified binders without penalizing suppliers or risking the users.

Author Information

Hossain, Zahid
Department of Civil Engineering, AR State Univ., AR, US
Ghosh, Debaroti
School of Civil Engineering and Environmental Science, The Univ. of Oklahoma, Norman, OK, US
Zaman, Musharraf
School of Civil Engineering and Environmental Science, and Alumni Chair Professor of Petroleum and Geological Engineering, College of Engineering, The University of Oklahoma, Norman, OK, US
Hobson, Kenneth
Oklahoma Department of Transportation, Oklahoma City, OK, US
Pages: 14
Price: $25.00
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Stock #: JTE20140061
ISSN: 0090-3973
DOI: 10.1520/JTE20140061