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The model developed tries to predict the stresses and strains of the structure of the pavement in a more real way, doing a lineal elastic structural analysis in three dimensions with capacity to model loads of double axes, that which constitutes an advance regarding two-dimensional axisymmetrical models that only represent the state tense-deformational of the pavement under loads of simple axes. Earlier stages of this research showed two-dimensional models under different load scenarios, league between layers and nonlinear constitutive models, however the purpose is to move towards analysis methodology stress-strain state under standard loads. The model was implemented in the Algor© program and a comparison with the Elsym5 multilayer freeware was performed. The results warn the existence of shear stress concentrations that can be causing major flaws that are not considered in traditional design methods which could lead to the possibility of reassessed., El modelo desarrollado busca predecir los esfuerzos y deformaciones de un pavimento de manera más real, realizando un análisis elástico tridimensional con solicitaciones de carga de ejes dobles, constituyéndose en un avance respecto de modelos axisimétricos bidimensionales que sólo representan el comportamiento bajo cargas de ejes sencillos. Etapas anteriores de esta investigación dan cuenta de modelos bidimensionales de carga simple bajo distintas hipótesis de liga entre capas y modelos constitutivos no lineales, no obstante, el propósito es avanzar en la metodología de análisis del estado tenso-deformacional ante cargas estándar. El modelo se implementó en el programa Algor© y se realizó una comparación con el programa multicapa de distribución libre Elsym5. Los resultados advierten la existencia de concentraciones de esfuerzos de corte en la capa asfáltica que pueden ser causantes de fallas importantes que no son tenidas en cuenta en los tradicionales métodos de diseño lo cual podría llevar a la posibilidad de revaluarlos.

HP&R 5168, As the axle load increases, higher tire pressures become more popular for long-haul truck operators. To collect data on tire pressures and the types of tires in use, a survey was carried out at a weigh station located on Interstate 5 in Oregon during the summer of 1986. Of the tires surveyed, 87% were of radial construction. The average measured pressures (hot) of the radial and bias tires were 102 psi and 82 psi, respectively., This study investigates the influence of increased tire pressures on the fatigue and rutting performance (in terms of vertical compressive stress, tensile strain, and compressive strain) of asphalt-surfaced pavements, through use of elastic layer analysis (ELSYM5), for two typical state highways in Oregon. This theoretical analysis shows that the effect of increased tire pressure on vertical compressive stress is significant in the asphalt wearing layer. As tire pressure increases, the maximum tensile strain at the bottom of the asphalt layer increases., Theoretical equivalency factors for the two asphalt pavements (SN=3.0 and 3.4) were developed using ELSYM5 to take into account tire pressures (80, 100, 125, and 150 psi) and number of tires per axle (2, 4, and 8 tires). A single axle with an 18-kip load, dual tires, and a tire pressure of 80 psi was used as a standard axle load and tire pressure. The results indicate that a 25% increase in tire pressure could result in a 40 to 60% increase in the equivalency factor for a dual-tired single axle with an 18-kip load or a tandem axle with a 34-kip load., In order to evaluate current asphalt concrete specifications and mix design criteria, aggregates from four different sources were tested. Two of the aggregates were treated with 1% lime slurry prior to testing. Six different aggregate gradations were tested. In general, the creep stiffness decreased proportionally to the percentage of fines passing the #200 sieve. Results show that treating the aggregates with 1% lime slurry improves the resistance to deformation of the asphalt concrete mixes.