In the last few years, there has been a great focus on human health and improving working conditions. Within this context, it is necessary to study the impact of the highway construction on the quality of life of workers and the environment. This paper aims to study polycyclic aromatic hydrocarbons (PAHs) emission from different bitumens commercialised in Brazil (conventional, modified by polymer or rubber and natural asphalt). The bitumens were submitted to conventional (Brazilian specifications) and rheological (SUPERPAVE classification) tests. The most usual application method is as a hot mixture. When heated, the bitumen releases volatile species and solid particles carried by gases, and this mixture is called bitumen emissions. In this fume, there are organic substances (PAHs), some of which may be carcinogenic. Therefore, the fume emitted during bitumen heating is harmful to health and should be considered both from the environmental sustainability and the worker health points of view. PAH studies were done alongside with other studies where the bitumen and the emission of some PAHs were correlated, which were measured through an experimental apparatus that generates and collects the bitumen fume. The equipment used was a nominated extraction and collection device (ECD) and the tests were conducted on laboratory benches. The fumes were collected in ECD and analysed by liquid chromatography–mass spectrometry to quantify the amount of emitted PAHs. From the research, it was possible to verify if bitumens with different behaviours at paving, from the perspective of sustainability and different impacts to the environment and human health. These emissions have an impact on health and the environment, which require further understanding.

Fatigue cracking is the main type of distress in flexible pavements in Brazil. Numerical models that are based on viscoelastic continuum damage (VECD) theory can help to explain the damage evolution process in asphalt mixtures, thereby allowing the proper analysis of the fatigue phenomenon. This paper aims to characterise and verify the fatigue behaviour of four test sites constructed with dense asphalt mixtures in Santa Maria, Brazil, employing field monitoring, linear viscoelastic characterisation, uniaxial cyclic fatigue testing, the simplified VECD (S-VECD) model, and FlexPAVE^TM software. This study’s results are coupled with a cost/benefit analysis of the evaluated test sites. The constructed sites are compared to simulated optimal pavement designed using FlexPAVE^TM and fatigue damage transfer function. The results indicate that this study’s methodology can predict fatigue damage evolution by identifying early cracking in two of the test sites and capturing good fatigue resistance in the other two sites. Furthermore, in both cases of early cracking, the design requirements for fatigue resistance could be met by increasing the asphalt layer thickness (optimal pavements), which significantly reduced the US$/N_FATIGUE ratio. Thus, an improved cost/benefit ratio was realised for the pavements designed using this methodology and analysed using only an established fatigue criterion.

The present paper presents the rutting evaluation of different asphalt mixtures in use in the state of Rio Grande do Sul, Brazil’s southernmost-region, through the uniaxial repeated load test and the monitoring of mixtures performance in field, culminating in a criteria proposal for the parameter Flow Number depending on traffic. For this, five distinct asphalt binders were studied, five grain size distributions, three warm mixtures and 21 hot mixes, with different mineralogical types of aggregates, and 15 monitored test sites distributed geographically throughout the state. The results indicated that the binder modifications were the most influential characteristics in the asphalt mixtures rutting. Also, it was verified that the Flow Number criteria proposed so far in the country present significant differences. In this way, a new criterion was suggested, and it is possible to infer a good applicability for asphalt concretes, except for warm mixes and those with rubber binder.

Ultra-thin concrete overlays or ultra-thin whitetopping (UTW), are an attractive alternative to traditional practices for the rehabilitation of asphalt pavements. However, it is widely accepted that the exiting pavement should have substantial stiffness to make a UTW a rehabilitation option. This paper re-examines this hypothesis using the performance results and structural evaluation of two experimental sections in Brazil. It is shown that structural contribution of the existing pavement is important for good performance of UTW. However, it appears that the ability of the existing pavement to ensure composite action of the individual slabs in the UTW is more important than its contribution to the flexural stiffness.

Asphalt pavement failure is directly related to the traffic and climate effects. Temperature and moisture severely impact pavement service life. It is known that moisture changes the stiffness and stress–strain distribution and all the mechanical behaviors of the mixture/structure. There is a huge interest in studying the impact of water on the behavior of flexible pavements, mainly on freeze–thaw regions under tropical climates with high rainfall levels. The scope of the present paper was to check the susceptibility to moisture-induced damage of dense asphalt mixes produced and applied on highways in Brazil’s southernmost region using different laboratory tests: visual adhesion of coarse aggregate; tensile strength ratio (TSR), and dynamic modulus ratio (DMR). Thus, this study evaluated the morphological, chemical, and mineralogical properties of aggregates from 11 quarries, as well as the interaction between aggregates and the respective bituminous binders. Rocks with high Si contents performed worse in visual adhesiveness tests; chemical ratios such as Fe/Si above 1 and Ca/K above 5, as well as the rougher texture of aggregates, considerably improved the coating, reducing the failures in adhesion. Results of TSR and DMR, after applying the induced moisture damage cycle, indicated greater susceptibility to conventional binders than mixtures containing modified binders in their composition. The action of moisture damage for most mixtures caused a reduction in strength and stiffness, warning of a decrease in the binder’s ability within the mixture, completely changing the distribution of efforts within the structure. Therefore, from this study, it is possible to suggest using DMR instead of TSR to assess susceptibility to moisture damage.