Multi-scale evaluation of the mechanical properties of asphalt mortar under different aging conditions

ABSTRACT

Since asphalt mortar is highly heterogeneous and occurs as an interfacial bonding material between the asphalt-binder and aggregate, it is very important to have a detailed and adequate understanding of its mechanical properties at a multi-scale (micro and macro) level analysis. In this study, the fundamental properties of the asphalt mortar were evaluated and quantified using molecular dynamic simulations. The tensile strength, stress-separation responses, and adhesive-bonding strength were numerically measured and characterised from a micro perspective. Other mechanical properties such as the complex modulus, low-temperature stiffness modulus, hardness, and elastic modulus were also experimentally measured to verify the dynamic simulations and modelling results. In comparison to the macro experimental test results, it was found that the micro-simulated results were superior in terms of characterising the mechanical properties of the asphalt mortar. Whilst the tensile strength, adhesive-bond strength, and hardness of the asphalt mortar changed significantly as a function of aging, the stress-separation responses and elastic modulus were hardly affected. Overall, the study findings indicated that multi-scale characterisation of the mechanical properties of asphalt mortar is a potentially promising methodology for quantitatively evaluating and understanding the mechanical properties.

KEYWORDS:

• Asphalt mortar
• mechanical properties
• multi-scale analysis
• molecular simulation
• dynamic modelling

Acknowledgments and disclaimer

This work was supported by the National Natural Science Foundation of China (No.52008235), the Special Foundation of Achievements Transformation Guide of the Department of Science and Technology of Shanxi Province (No.201804D131034), and the Science and Technology Project of Shanxi Transportation Holdings Group Co., LTD (No.19-JKKJ-55 and No.20-JKKJ-43). The authors are grateful and thank all those who helped during this research study and documentation of this paper.

The contents of this paper, which is not a standard nor a design/bidding document, reflect the views of the authors who are solely responsible for the facts and accuracy of the data presented herein and do not necessarily reflect the official views or policies of any agency or institute. Trade names were used solely for information purposes and not for product endorsement, marketing, advertisement, promotions, or certification. The authors declare no competing interests.

Disclosure statement

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

Additional information

Funding

This work was supported by National Natural Science Foundation of China: [Grant Number 52008235].