Semi-circular notched beam testing procedure for hot mixture asphalt

Abstract

The purpose of this study was to facilitate and improve the methodology used for hot mixture asphalt fracture evaluation and to establish a procedure to overcome the difficulty of preparation of hot mixture asphalt beam samples for fracture testing. This research investigated and compared the stress intensity factor (KIC) determined by two test set-ups: the semi-circular notched beam and the single edge notched beam tests. In addition, the temperature effect was evaluated by the determination of KIC at different temperatures. Two Superpave mixtures were used for experimental verifications. Results illustrated that there was no significant difference between KIC determined by semi-circular notched beam and single edge notched beam tests within the acceptable statistical margin of error. Finite-element and discrete-element models were created to aid in the verification of the results from the laboratory tests. Further, the evaluation of KIC by semi-circular notched beam at different temperatures showed a similar pattern for all tested mixtures. It was observed that the linear elastic fracture mechanics theory restrictions were not violated when determining KIC for all testing conditions. Overall results suggested that the semi-circular notched beam test can be used for fracture evaluation of hot mixture asphalt, as a screening tool for weak mixtures due to its simplicity and repeatability.

Intermediate Temperature Fracture Resistance of Stone Matrix Asphalt Containing Untreated Recycled Concrete Aggregate

“…Fracture occurs when the available energy is greater than the material resistance, which may include forms such as surface energy or plastic work (Anderson, 2017). From the various test methods available for determining the fracture energy of a material, the primary output is a load-displacement curve which can subsequently be used to determine the fracture properties based on the work done as determined from the area below the curve as seen in Figure 5 ( Abu et al, 2014).…”

Effect of Mix Design Variables on Thermal Cracking Performance Parameters of Asphalt Mixtures

“…A study employed by Haas et al ( 12 ) using multiple regression models concluded that minimum pavement temperature, coefficient of thermal contraction, and pavement layer thickness have the highest correlation to fracture energy. Abu Abdo et al ( 13 ) investigated the effect of mix variables on fracture toughness and concluded that a decrease in asphalt content is associated with lower fracture toughness values. A study by Braham et al ( 14 ) performed a statistical analysis and concluded the significance of binder content, aggregate type, and temperature on fracture energy of mixtures.…”

Editorial

“…The issue concludes with a paper by Abu Abdo et al (2014) aimed at improving the evaluation method used in hot mixture asphalt fracture testing. The characteristic strength of materials used in the construction and maintenance of the strategic network is a reoccurring theme in issues of Transport and is central to pavement performance in the face of forecast increases in traffic and environmental variation.…”