Effect of sample geometry and air voids on the 3-Point Bend Cylinder (3PBC) fatigue test for asphalt concrete

Abstract

As part of NCHRP IDEA Project 218, a new testing protocol called Three-Point Bend Cylinder (3PBC) Test was developed to speed up the fatigue characterization of asphalt mixtures. In this paper, the effects of sample geometry and air voids on the 3PBC fatigue test were investigated. The results showed that the VECD theory was successfully applied to all the selected geometries. This allowed the determination of fatigue life at any desired strain levels, temperatures, and frequencies. Based on the selected levels for each factor, specimen diameter significantly affected the 3PBC test results and fatigue lives. Specimen span length and air void content, however, did not appear to have considerable effects on the fatigue lives of the asphalt material. It should be noted that the sample variability of the 3PBC test may have softened the effects of air voids on the fatigue lives of the asphalt material.

KEYWORDS:

• Asphalt material
• laboratory testing
• VECD
• fatigue characterisation
• sample geometry
• air void

Acknowledgments

The work described in this article was conducted as part of the National Cooperative Highway Research Program Innovations Deserving Exploratory Analysis (NCHRP IDEA) through NCHRP-IDEA Project 218, Development of a Fast and Cost-Effective Asphalt Mixture Fatigue Test System. The authors greatly appreciate the support of Dr. Inam Jawed, NCHRP IDEA, and the input of the project panel. The contents of this paper reflect the views of the authors, who are responsible for the facts and the accuracy of the data presented herein. The contents of this paper do not necessarily reflect the official views or policies of the sponsor at the time of publication.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data, models, and code generated or used during the study appear in the submitted article.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by National Cooperative Highway Research Program Innovations Deserving Exploratory Analysis (NCHRP IDEA) [Project Number: 20-30/IDEA 218].