Volume 59, Issue 325, January 2023

Variation in asphalt concrete properties with testing mode

Saad Issa Sarsam^♦

Professor, Sarsam and Associates Consult Bureau (SACB), Former Head, Department of Civil Engineering, College of Engineering, University of Baghdad-Iraq

^♦Corresponding author
Professor, Sarsam and Associates Consult Bureau (SACB), Former Head, Department of Civil Engineering, College of Engineering, University of Baghdad, Iraq

ABSTRACT

Asphalt concrete beam specimens were tested under controlled strain and stress conditions for dissipated energy, phase angle, flexural stiffness and permanent deformation. It was observed that higher permanent deformation, flexural stiffness and cumulative dissipated energy is achieved under constant strain mode. However, lower phase angle could be observed under constant strain mode. The fatigue life of constant strain mode of testing is longer by 128.5 % and the permanent deformation is higher by 733 % than that of constant stress mode of testing respectively. After the first load repetition, the constant stress mode exhibits a high phase angle of 47� as compared with 17� for constant strain mode. It was concluded that higher dissipated energy is required in case of constant stress while lower dissipated energy is required in case of constant strain to exhibit a permanent deformation than that required for the constant stress mode. Choice of the testing mode of asphalt concrete is essential in the evaluation of asphalt concrete properties and the variation in such properties is significant among the testing mode.

Keywords: Asphalt Concrete, Fatigue, Strain, Stress, Dissipated Energy, Phase Angle, Flexural Stiffness

Discovery, 2023, 59, e7d1010

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Published: January 2023