Weather at different locations in the Hungarian lowland in different seasons (winter, summer) and times of day (morning, noon) is investigated from the human biometeorological point of view. Human thermal load characteristics of weather are described in terms of clothing resistance and operative temperature. Individual human thermal load–thermal sensation relationships have been estimated to study weather variation in the cities of Sopron (cooler part of Hungary) and Szeged (warmer part of Hungary). In the clothing resistance model, the humans are walking at a speed of 1.1 ms⁻¹ in outdoor conditions without sweating. The main findings are as follows. (1) In the early summer mornings, the weather is sensed as “neutral” or “cool”, in these cases the inter-person variation effect is very small. (2) At noon in summer, heat stresses (clothing resistance parameter values less than −2 clo) are registered. In these cases, high temperature and irradiation, as well as low or moderate wind, characterized the atmospheric environment. Then, the inter-person variation effect is clearly visible. (3) The strength of summer heat excess at noon seems to be larger than the strength of winter heat deficit in the early morning. (4) Clothing resistance differences caused by inter-person variations and by weather variations between the cities of Sopron and Szeged are comparable in the majority of cases. When they are not comparable, the site variation effect is much larger than the inter-person variation effect. The clothing resistance model is constructed for individual use and it can be equally applied on both weather and climate data.

The precise determination of the rheological properties of road bitumen types is essen-tial for the reliable prediction of long-term pavement behaviour. The aim of this study is to compare different viscosity determination methods – approximations, capillary vis-cosity, Brookfield measurement, and complex viscosity determined by dynamic shear rheometer (DSR) – and to analyse their relationships with each other. Furthermore, the European and Australian bitumen classification standards are compared in terms of dynamic viscosity and penetration, according to which Australian bitumen types show more stable results. The statistical evaluation of the results obtained with the different methods was based on Pearson correlation analysis and relative deviation analysis. The results obtained show that the DSR measurements at 1.6 Hz are most closely related to capillary viscosity and best correlated with the other measurements, while the Heuke-lom equation relationship overestimates the dynamic viscosity. The Brookfield method provided higher viscosities for all tests. The study highlights that the results of different measurement methods can only be compared under shear conditions, and that the DSR-based approach can be more suitable for the introduction of a new European bi-tumen classification.

The accurate determination of the rheological properties of road bitumen types is essential for the reliable prediction of long-term pavement behaviour. At 60 °C, dynamic viscosity is a key rheological parameter characterising the shear-dependent viscoelastic behaviour of bitumen in the temperature range relevant to in-service pavement loading. This study aims to compare different viscosity determination methods—approximations, capillary viscosity, Brookfield measurement and complex viscosity determined by a dynamic shear rheometer (DSR)—and to analyse their relationships with each other in order to find the best method for bitumen classification. Furthermore, the European and Australian bitumen classification standards are compared in terms of dynamic viscosity and penetration, according to which Australian bitumen types show more stable results, as the CV% is less than 10 percent. The study is based on the testing of Hungarian paving-grade bitumens (B50/70, B70/100) and Australian viscosity-graded bitumens (C170, C320), with the comparison of a total of 191 samples obtained from industrial production. The statistical evaluation of the results obtained with the different methods was based on Pearson correlation analysis and relative deviation analysis. The results indicate that the DSR measurement at 1.6 Hz shows the closest agreement with capillary viscosity, with a linear correlation coefficient of 0.95, and exhibits the strongest overall correlation with the other measurement approaches, whereas the Heukelom equation tends to overestimate the dynamic viscosity. The Brookfield method yielded higher viscosity values in all tests. The study highlights that the results of different measurement methods can only be compared under specific shear conditions, and a DSR-based approach can be more suitable for the introduction of a new European bitumen classification system.