SEDL / STP / STP1147-EB / STP24226S

The Effect of Aggregate Gradation on the Creep Response of Asphalt Mixtures and Pavement Rutting Estimates

Matthews, JM
Assistant Professor, Civil Engineering at Temple University, Philadelphia, PA

Monismith, CL
Robert Horonjeff Professor of Civil Engineering and Research Engineer, University of California, Berkeley, CA

Pages: 19    Published: Jan 1992

Download this paper for $25 PDF (264K)          View License Agreement
Abstract

The objective of this paper is to determine the influence of aggregate grading on asphalt mixture performance in rutting on heavy duty highways. For this purpose, the Hveem stabilometer method and simple creep tests (unconfined) were utilized. In both methods, Watsonville granite aggregate and AR 4000 and AR 8000 asphalts were used to cast specimens by kneading compaction. Two types of aggregate gradations were used: (1) California standard 0.5 inch (13 mm) maximum size, medium gradation and (2) California standard 0.5 inch (13 mm) maximum size, coarse gradation. The rut depths were predicted for a total of 15 cases, consisting of 4 temperature conditions, 2 aggregate gradations and 2 asphalts. The conclusions drawn, from the results of both methods of measuring performance (stabilometer and creep tests), were that (i) the medium graded mixtures provided significantly better performance in rutting than the coarse graded mixtures, and (2) temperature has more influence on rutting than the aggregate grading.