Retroanálise de bacias de deflexão e dimensionamento mecanístico empírico de pavimentos asfálticos: estudo de caso

Abstract

Asphalt pavements have a structure of finite layers that mechanically interact with each other based on the different stiffness parameters of the materials constituting the layers. The empirical mechanistic method of designing asphalt pavements seeks to correlate the tensions of the variable loads of the vehicles with the existing deformations in the pavement. The effects of the application of cyclic loads corroborate the appearance of cracks caused by fatigue and sinking of wheel tracks throughout the period that the pavement was designed. To carry out the design, the thicknesses of the pavement layers were made compatible with the constituent materials. The objective of this work was to retro-analyze the deflection basins obtained in the experimental track of the Central de Abastecimento de Goiás (CEASA-GO), in the municipality of Goiânia, and the asphalt pavement was built with sub-base and base of recycled aggregates of solid waste from civil construction and asphalt concrete coating. The retroanalyses were performed using the BackMeDiNa software, made available by the National Department of Transport Infrastructure (DNIT), using data from deflectometric tests carried out on the runway using the Benkelman beam. Benkelman beam test data were fitted to the data model obtained from the Falling Weight Deflectometer (FWD) test, indicated for use in the BackMeDiNa software. After performing the retroanalyses and adjusting the modulus of elasticity of the pavement layers, a new dimensioning of the asphalt pavement was carried out, using the mechanistic-empirical method called National Pavement Dimensioning Method (MeDiNa), software also made available by DNIT. The mechanistic-empirical analysis made it possible to evaluate the useful life of the pavement in terms of damage by cracked area and permanent deformation. The analyzes provided by the new design were related to the actual state of conservation of the experimental track and demonstrated consistency regarding the good state of conservation of the pavement.