Análise estrutural e econômica de pavimentos flexíveis com adição de RAP na camada de revestimento, dimensionados pelo método do DNER e MeDiNa

Abstract

The Brazilian construction industry has been encouraged to invest in materials technology, mainly those that meet the precepts of sustainability, and updates on methods for sizing flexible pavements, considering that a large portion of Brazil's road network consists largely of this type of pavement and has suffered from premature wear, leading to constant maintenance. The reuse of milled material, also called Reclaimed Asphalt Pavement (RAP), has emerged as an alternative for reducing paving costs and the environmental impact caused by this service. This research sought to make a structural and cost comparison of implementing pavements with the addition of RAP at rates of 0%, 10%, 30%, and 50% in the surface layer, sized by the method of the National Highway Department - DNER (1981) and by the National Sizing Method (MeDiNa). Initially, data collection was conducted from literature sources on the materials that would be used in the layers of the pavements studied. After sizing, a structural and implementation cost comparison was made for one kilometer of road for all the structures proposed in the research. Structure 01, with 0% RAP and sized by DNER (1981), had the lowest cost, however, upon analyzed by the MeDiNa, permanent deformation failure was observed in the first month of the project and fatigue at the 25th month of use. Structure 02, with 0% RAP, was the costliest among all, however, like the other structures sized by MeDiNa, it will withstand traffic demands over the project’s duration (10 years). The number of equivalent fatigue failure requests (Neq) between the structures showed that structure 02 is 67% more economical. For the other structures, as the RAP content increases, the implementation cost decreases, reaching a reduction of 79% for the structure with 50% RAP in its surface layer. Therefore, through the results obtained in the research, it was observed that MeDiNa proved to be more suitable for meeting the estimated project time, besides allowing the use of different types of materials available for pavement execution without compromising its efficiency, as is the case with recycled asphalt mixtures containing RAP. It was also observed that increasing the RAP content in the asphalt mixture reduces the cost of the structure, saving cost in pavement implementation.