ISSN: 0090-3973
Published Online: 21 August 2008
Page Count: 7

Evaluating the Shear Resistance of Hot Mix Asphalt by the Direct Shear Test

Wang, Hai-nian
Key Laboratory for Special Area Highway Engineering of Ministry of Education, Chang’an University,Shaanxi,

Liu, Xi-jun
Pavement Engineer,Huangpu Bridge Construction Company,Guangdong,

Hao, Pei-wen
Professor,Key Laboratory for Special Area Highway Engineering of Ministry of Education, Chang’an University,Shaanxi,

(Received 4 March 2008; accepted 17 July 2008)

Abstract

The shear strength of hot mix asphalt (HMA) was evaluated with a direct shear device in this research. The indirect unconfined compression test was adopted to calculate the cohesion and the angle of friction of HMA mixtures. The influence of asphalt content, loading rate, and testing temperature on the shear strength of HMA mixtures was also investigated. The shear resistance properties of asphalt mixtures were investigated by a direct shear device using five gradations (i.e., two intermediate-graded and three large-stone mixtures). The results show that the shear strength is highly related to rutting resistance of the HMA mixture at a high temperature. Testing parameters have great influences on the cohesion component and low influences on the angle of friction. The shear strength of asphalt mixtures has good correlations with the dynamic stability through wheel-tracking tests. The angle of friction is susceptible to the mixture gradations and their design methods. The well-interlocked gap-graded mixtures have greater friction angles than the continuously dense-graded mixtures.

Keywords:
asphalt mixture, shear strength, direct shear test, test method

Paper ID: JTE101732
DOI: 10.1520/JTE101732
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