Strength against Deformation of Asphalt Concretes at High Temperature

Kwang W. Kim

Professor, Department of Regional Infrastructures Eng.,

Kangwon National University, Chun Cheon, 200-701 Korea

e-mail: asphaltech@hanmail.net

Young S. Doh

Senior Researcher, Center for Advance Mineral Aggregate Composites

Kangwon National University, Chun Cheon, 200-701 Korea

e-mail: youngsdoh@hanmail.net

Abstract

This study shows procedure and results of developing a strength property which has high correlation with deformation characteristics of asphalt concrete mixtures. The test procedure is designed to apply a static load to the compacted asphalt samples at 60^oC and calculate the strength by using the deformation at failure point.  To evaluate validity of this test, various mixtures, dense-graded, gap graded and Superpave mixtures were prepared with two aggregates and eight binders using two loading head types at the loading speed of 50mm/min.  Maximum load and deformation at maximum load were recorded for each test and deformation strength, S_D, was calculated using a newly developed equation.  For the same mixture, wheel tracking test was performed and two rut parameters, depth of rut and dynamic stability were obtained. The relationship between S_D and rut parameters was evaluated using regression analyses.  In most cases, R² values were found to be over 0.90.  This study results indicated that deformation strength is a simple test for estimating the deformation resistance of asphalt mixtures at high temperatures.