Numerical simulation of the overlay tester
The Overlay Tester (OT) is a relatively new testing procedure that characterizes the cracking resistance of hot mix asphalt (HMA) by evaluating the number of cycles to failure of an HMA specimen. The lack of repeatability and high variability of the results have been a concern to transportation agencies. A careful experimental review of the OT test protocol reveals the complex stress and strain distributions that should be understood in order to improve the certainty associated with the test. The objective of this thesis is to present the numerical modeling of the OT test through finite element analysis (FEA). When calibrated, the model can be used to assess the potential success of different parameters associated with improving the performance of the testing procedure. Different material models and fracture mechanisms were implemented to accurately replicate the laboratory behavior of the HMA specimen. The model was then calibrated with the resultant load-displacement curves from the laboratory tests. Simultaneously, a parametric study was performed to analyze certain aspects of the OT test procedure such as epoxy strength and testing dimensions that may be improved to increase its success. Developing an accurate and calibrated FEA representation of the experiments in the lab will lead to a better understanding of the parameters that affect the success of OT as well as a model that can be applied to other types of asphaltic material testing.
Gutierrez, Andrea, "Numerical simulation of the overlay tester" (2016). ETD Collection for University of Texas, El Paso. AAI10151223.