Determinação laboratorial do teor ótimo de ligante de misturas asfálticas utilizando agregados característicos de certas regiões do estado do Amazonas

Abstract

For a country to grow continuously and sustainably, it is necessary to make major investments in transport infrastructure, whether in the road, rail, waterway or air areas. The Brazilian road network is a fundamental element for production chains, as it promotes the integration of regions. And sidewalk quality is one of the main determinants of user performance during their journeys. The asphalt coating is the top layer designed to directly resist the actions of traffic and transmit them in an attenuated way to the lower layers, waterproofing the sidewalk, as well as improving rolling conditions, providing comfort and safety. Asphalt coatings are made by combining coarse and fine aggregates, filler and asphalt binder to produce an asphalt mixture, including asphalt concrete (AC), for example. In practice, hot-machined asphalt concrete (HMA) is used in road sidewalk surfacing, where it is made up of technologically selected materials and dosed in processes from manufacture to execution. The static or dynamic loads acting on the surfacing can generate excessive elastic or plastic deformations, as well as the disintegration of components (aggregates/binders) or even the loss and reduction of the compaction layer. However, the material that will be used to make up the surfacing must have a high binding capacity, avoiding permanent horizontal movements. Therefore, the dosages of asphalt mixtures (proportions of mineral aggregates and optimal or design binder contents) are determining parameters for the considerable performance of a road. The following work was based on the technological characterization of the materials that make up hot-mix asphalt concrete (HMA), such as: coarse aggregates, fine aggregates and asphalt binder, using the Marshall dosing method in order to make its applicability rational and symmetrical with its individual characteristics in road sidewalks in the state of Amazonas. This method has several alternatives for choosing the design asphalt binder content. The choice of asphalt content primarily for asphalt concrete bearing layers is based solely on the volume of voids (Vv), corresponding to 4%, or the Vv corresponding to the average of the specifications. For the materials collected, two granulometric compositions from the Mercês and Britamazon quarries were dosed and their optimum contents determined.