Effect of 3D aggregate shape on thermo-mechanical properties of asphalt concrete using a mesostructure-based homogenisation method

ABSTRACT

Morphological characteristics of aggregates have long been recognised as an essential factor influencing the thermo-mechanical behaviour of asphalt concrete. However, studies on accurate quantification of this influence are still very limited. For this reason, the present study developed a mesoscale finite element method to investigate the effects of three-dimensional (3D) aggregate shape on the complex modulus, thermal expansion coefficient, thermal conductivity, and mesoscale responses of asphalt concrete. An upscaling homogenisation method was adopted to predict the effective thermo-mechanical properties of asphalt concrete. The 3D true sphericity (3DTS) was used as an index to characterise the aggregate shape. The computational results showed that the temperature and loading frequency significantly affect the role of aggregate shapes in determining the effective dynamic modulus of asphalt concrete. The high-angularity aggregates can increase the deformation resistance of asphalt concrete under thermal load, and thus reduces the thermal contraction coefficient of asphalt concrete. However, aggregate shape has no significant effect on the thermal conductivity of the asphalt concrete. In addition, the asphalt concretes with less angular aggregates have stronger low-temperature damage resistance, while the aggregates with high angularity can improve the rutting resistance of asphalt pavements.

KEYWORDS:

• Asphalt concrete
• aggregate shapes
• mesoscale model
• homogenisation process
• thermo-mechanical properties

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 51808098,51878122].