## 5 Summary and Conclusions  
This paper presents the study of low-temperature creep properties of asphalt mixtures and the methods of thermal stress assessment. Three point bending and uniaxial tensile creep tests were applied to calculate thermal stresses at low temperatures. Based on the test results and analysis, the following conclusions can be drawn:  
1. According to different creep test methods applied in the study, lower strain values of creep curves were obtained for the Tensile Creep Test (TCT) than for the Bending Beam Creep Test (BBCT), especially at lower temperatures. 2. Stiffness curves derived from both creep tests (BBCT and TCT) differ at all the tested temperatures - both in terms of shape and values. For low temperatures (\(-10\)\({}^{\circ}\)C and lower) results obtained from the TCT presented higher values of stiffness modulus. The situation is opposite at temperatures higher than \(0\)\({}^{\circ}\)C, where the results obtained from the BBCT present higher values. 3. Master curves determined on the basis of the TCT results showed higher values of stiffness modulus for temperatures <0 \({}^{\circ}\)C and lower for temperatures >0\({}^{\circ}\)C in comparison to those determined from the BBCT. 4. \"Branching\" modification of the Richards model correctly described the master curves determined from the BBCT results. In the case of the TCT results, master curves presented some discrepancies and a new model should be determined. 5. The Arrhenius shift factor function presented reliable results for both tests (BBCT and TCT). In the case of the WLF shift factor function, the BBCT results showed significantly decreased values at temperatures higher than \(0\)\({}^{\circ}\)C. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Mixture Designation**} & \multirow{2}{*}{**TSRST**} & \multicolumn{4}{c}{**Thermal Stress Calculation Method (Data Source)**} \\ \cline{3-6}  & & **Hills \& Brien** & **Hills \& Brien** & **Monismith** \\  & & **(BBCT)** & **(TCT)** & **(BBCT)** & **(TCT)** \\ \hline AC 11S 70/100 & \(-\)26.4 & \(-\)29.0 & \(-\)21.0 & \(-\)29.5 & \(-\)25.0 \\ LT & & & & & \\ \hline AC 11S 50/70 & \(-\)25.7 & \(-\)26.5 & \(-\)19.5 & \(-\)27.5 & \(-\)23.5 \\ MT & & & & & \\ \hline AC 11S & \(-\)29.5 & \(<\)\(-\)30.0 & \(-\)28.5 & \(<\)\(-\)30.0 & \(-\)29.5 \\
45/80-55 MT & & & & & \\ \hline AC 11W 35/50 & \(-\)22.3 & - & \(-\)20.5 & - & \(-\)25.5 \\ MT & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Comparison of predicted failure temperatures (mean values). Results of thermal stress calculations indicated that higher reliability was obtained for the viscoelastic Monismith method based on the TCT results. The highest agreement with the TSRST results was also obtained for the Monismith method based on the TCT results. 7. No clear relationships were obtained between the failure temperatures predicted from different methods of thermal stress calculation. The highest agreement was obtained for the viscoelastic Monismith method calculated based on the TCT results, for which 2 of 4 cases were the determined values of failure temperature in good agreement with the TSRST results. 8. The main limitation of the study was related to the methodology of the TCT method. The test method was applied and conducted according to the European standard EN 12697-46. In the TCT, the time of loading is long (8 h) and an additional measurement period of 2 h is also recommended after unloading. The authors have come to the opinion that the time of loading can be shortened, but this issue requires further research. [PERSON] conceived and designed the experiments; [PERSON] and [PERSON] coordinated the experiments; [PERSON] and [PERSON] analyzed the TCT and BBCT data; [PERSON], [PERSON] and [PERSON] wrote the paper; [PERSON] coordinated and edited the paper. The research was partly supported by the project RID-1B, financed by the National Center for Research and Development and the General Directorate for National Roads and Motorways under the program \"Development of Road Innovations\".