01660849

Component

For laboratory assessment of the thermal cracking resistance of asphalt mixtures, the cooling test or Thermal Stress Restrained Specimen Test (TSRST) simulates fully restrained pavements, as they occur in field. Due to cooling and prevented shrinkage, cryogenic stresses are built up until the tensile strength of the specimen is exceeded and the specimen fails by cracking. This test setup allows for the analysis of various viscoelastic parameters, e.g. relaxation, evolution of tensile stresses, and tensile strength. Thus, a comprehensive view on the low temperature behaviour is possible. Standard TSRST is controlled by setting the cooling rate of the air within the chamber at a fixed value, e.g. -10°C/h. In thermodynamics, the actual cooling rate of objects is not only influenced by the cooling but also by external conditions like humidity, air velocity, radiation condition, etc. This paper investigates the impact of additional cooling parameters rather than only the air cooling rate. Two test machines of the same manufacturer that differ in the year of production and the setup of the climate chamber are compared. An initial wide scatter of test results from the two devices could be explained by taking thermodynamics into account and the reproducibility could be significantly enhanced.

This paper was sponsored by TRB committee AFK50 Standing Committee on Structural Requirements of Asphalt Mixtures.

18-00253

English

0000-0002-8329-8687

12p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; Photos; References; Tables

Asphalt mixtures; Cooling; Materials tests; Thermal degradation; Thermodynamics

Highways; Materials; Pavements

Transportation Research Board Annual Meeting 2018 Paper #18-00253

TRIS, TRB, ATRI

Jan 8 2018 10:05AM