Experimental study on thermophysical properties of HMA during compaction

ABSTRACT

The thermal parameters are key parameters for evaluating the temperature field and temperature stress of asphalt pavement. However, due to the restriction of tradition test method, the thermal parameters of asphalt and asphalt mixtures measured by various researchers are quite different. Therefore, it is particularly important to introduce a simple and standard test method for thermal parameters of asphalt mixtures. This research proposed a novel test method to precisely determine the thermal parameters of asphalt mixture during compaction temperature, the effects of different air voids on the thermal diffusivity and parameters were evaluated. Differential scanning calorimetry (DSC) was used to measure the heat flow curves of asphalt and asphalt mixture, and the calculated and measured specific heat values of the mixture were obtained. Then the corresponding thermal conductivity was calculated from the conversion relationship between thermal parameters. The results indicated that the thermal conductivity converted from the calculated value of specific heat is close to previous studies, but the thermal parameters of the temperature field during the compaction process can be obtained accurately and conveniently. This research provides a new method for the thermal properties evaluation of asphalt and asphalt mixture .

KEYWORDS:

• Asphalt
• asphalt mixture
• thermal parameters
• DSC test
• thermal diffusivity
• thermal conductivity
• specific heat

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The research was supported by the National Key R&D Program of China [grant number 2018YFB1600100]; and National Natural Science Foundation of China [grant numbers 51908072, 51778071 and 51808058]; Huxiang high-level talents gathering project - innotive talent (grant number 2019RS1048); open fund [grant number kfj180103] of National Engineering Laboratory of Highway Maintenance Technology (Changsha University of Science and Technology).