The Universidad de los Andes linear test track apparatus

This paper describes the development of a new apparatus to perform accelerated loading tests on pavement structures. This apparatus is the main component of the laboratory of physical modeling of pavements at the University of Los Andes in Bogota Colombia. The components of this laboratory are: (i) a concrete pit 11.4 m long, 3.2 m wide and 3.5 m deep; the pavement structure is constructed in this pit and it allows the control of the water table and the environmental conditions over the pavement surface; (ii) the linear loading test apparatus, and (iii) a mini asphalt plant that simplifies tests with modified asphalt materials. The loading apparatus is a linear test track that applies the load of a half axle truck (dual tires with maximum load of 75 kN). This new linear test track has an original control system based on the combination of an electrical frequency power controller, and a set of air springs. The air springs absorb the energy of the moving load when slowing down close to the ends of the track, and it allows generation of energy during the acceleration process. This system permits high velocities while saving energy. This paper describes the main components of the apparatus and presents some results of a first test carried out using this new APT device.