Date of Graduation

12-2016

Document Type

Thesis

Degree Name

Bachelor of Science in Civil Engineering

Degree Level

Undergraduate

Department

Civil Engineering

Advisor

Dr. Braham, Andrew

Reader

Dr. Prinz, Gary

Second Reader

Dr. Hale, Micah

Abstract

Asphalt concrete is commonly used as the surface layer on pavements because of its convenience, low cost, and smooth ride (Wagoner, 2005). However, there is a significant problem with the cracking and deterioration of asphalt concrete roads. The initiation of cracking in asphalt must be better understood in order to further improve pavement design. Fracture energy is the amount of energy needed to separate two surfaces. The semi circular bend (SCB) test can be used to measure the fracture energy of asphalt concrete. Currently, this method uses a semicircular specimen with a rectangular notch in a three-point bend compression test. Using a mechanically inserted rectangular notch creates a stress concentration at the top of the notch, causing the crack to initiate from one predetermined place: either on the left or the right of the notch. Therefore, the fracture energy found from the load vs. displacement curve may not representative of the true fracture energy of the specimen. In order to better isolate the fracture energy of asphalt concrete, this research will explore the fracture energy results of using a semicircular notch, a fatigue-cracked notch, and the traditional rectangular, mechanically inserted rectangular notch.

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