The fatigue behaviour of bituminous layers must be taken into account when dimensioning road structures and projecting streets. To satisfy this fatigue criterion, laboratory tests must be used to determine the material characteristics and fatigue life of bituminous mixtures. The aim of this article is to study the crack initiation stage using a specific laboratory test: the two-point constant strain bending fatigue test on trapezoidal specimens. The laboratory tests were carried out on three types of bituminous mixes used in the wearing course, each containing successively two different types of bitumen (one imported and one Romanian). The conclusions drawn from this article refer to the influence of mix type and bitumen on the characteristics obtained.

The study of the behavior of bituminous mixtures is a very old subject in the specialized literature, many specialists in the field trying to explain the causes of the degradations, considering different factors. The bituminous mixtures were initially used in the construction of road structures for roads, so that a few years ago they also started to be used in the road structures of airport surfaces. The subject of the current research study is a priority worldwide and contributes, through the obtained results, to the enrichment of knowledge regarding the behavior of airport bituminous mixtures. The complexity of this study was based on the multitude of laboratory tests carried out on the designed airport bituminous mixture, BBA 16, using complex modern and high-performance equipment and equipment that lead to the determination of the stiffness modulus at different temperatures and frequencies both on trapezoidal samples and on prismatic samples.

The context in which this study is conducted is represented by the need to improve road safety at T-intersections, which can be visibility-critical locations and of the risk of accidents. Therefore, this study is important to identify and solve potential problems related to sight distance in road intersections. Case studies on sight distance in intersections are an effective way to assess the impact of the factors that influence it on road safety. Currently, the three-dimensional study allows us to analyze the visibility in detail according to the standards and obtain the sight distance both in tabular format and the graphic representation of the sight distance. The visibility triangle is defined as the spatial region formed by the path of the vehicle traveling along the main road and the vehicle traveling along the side road intersecting leading to the conflict point. The area of the visibility triangle depends on the prescribed sight distances, which must be observed based on the travel speeds of the conflicting paths. In this three-dimensional analysis, the sight distance at the intersection between a national road and an access road to a quarry, in the “T” variant, was studied. In this study, the sight distance checks were made in the “T” shaped intersection according to AND 600, with the help of the 3D model and the Civil Site Design software. Also, the influence of the angle cut slope on the sight distance from the intersections was studied considering 2 slope inclinations namely 1:2 and 1:4.