Computer Simulation of Low Volume Roads Made from Recycled Materials
— Low volume roads are widely used all over the world. To improve their quality the computer simulation of their behavior is proposed. The FEM model enables to determine stress and displacement conditions in the pavement and/or also in the particular material layers. Different variants of pavement layers, material used, humidity as well as loading conditions can be studied. Among others, the input information about material properties of individual layers made from recycled materials is crucial for obtaining results as exact as possible. For this purpose the cyclic-load triaxial test machine testing of cyclic-load performance of materials is a promising test method. The test is able to simulate the real traffic loading on particular materials taking into account the changes in the horizontal stress conditions produced in particular layers by crossings of vehicles. Also the test specimen can be prepared with different amount of water. Thus modulus of elasticity (Young modulus) of different materials including recycled ones can be measured under the different conditions of horizontal and vertical stresses as well as under the different humidity conditions. Using the proposed testing procedure the modulus of elasticity of recycled materials used in the newly built low volume road is obtained under different stress and humidity conditions set to standard, dry and fully saturated level. Obtained values of modulus of elasticity are used in FEA.
Optimization of low volume road pavement design and construction
Hauser J., Ševelová L., Matula R., Zedník P. (2018): Optimization of low volume road pavement design and construction. J. For. Sci., 64: 74–85. Low volume roads in the Czech Republic are roads with lower traffic volume that primarily include forest and field roads, and they are an integral part of the Czech transport network. When building road pavements, we can use processes for surveying, designing, building and inspecting road constructions included in national and international, particularly European, standards. In addition, the roads are evaluated in terms of their environmental impacts, in order to maintain the quality of the environment. However, during the construction of road pavements decisions based on financial, time and other reasons are made. The decisions have impacts on the operation of roads and lead to other measures and additional costs of repairs and reconstructions. The article summarizes the authors’ research results from constructions of low volume road pavements and contains evaluations of laboratory and in situ material tests (soils, layers) of installed road pavements as well as evaluations of modelled laboratory and long-term monitored in
"Flying Triangulation" - a new optical 3D sensor enabling the acquisition of surfaces by freehand motion
In order to obtain complete 3D surface information of an object it is often necessary to acquire many partial 3D views. For this purpose, the sensor has to be moved (e.g. for the acquisition of sculptures or rooms). Further, in many cases a motion of the object relative to the sensor is unintended but inevitable (e.g. for medical applications such as intraoral measurements of teeth). Nearly all existing optical 3D sensors either lack an easy handling or require a standstill during the acquisition of a single partial 3D view, since usually multiple camera shots have to be taken for this purpose. This makes such measurements elaborate or even impossible.