MELO NETO, O. M.; http://lattes.cnpq.br/5202211822198962; MELO NETO, Osires de Medeiros.
Résumé:
The growing demand for raw materials and energy, and the increase in population justify the
use of the circular economy, which seeks to reduce environmental impact and economic gains.
The use of recycled asphalt pavement (Reclaimed Asphalt Pavement - RAP) in the production
of hot asphalt mixes (Hot Asphalt Mixtures - HMA) has been used in paving due to the scarcity
of virgin materials. However, the use of high percentages of RAP is conditioned to its
susceptibility to failure at low temperatures and to fatigue damage. The addition of rejuvenating
agents can partially restore the aged properties of the recovered binder. Hence, researching
industrial waste and by-products are necessary to bring solutions that foster the tendency to
work from a circular economy perspective, which is based on the economy and the circulation
of waste and by-products between different sectors, including road engineering. This work
evaluated the use of soybean oil sludge fatty acid (SSFA) as a rejuvenating agent for recycled
asphalt mixtures, as well as analyzed the technical, economic and environmental feasibility
regarding the circularity of these materials. In the first step, the characterization of the binder
was carried out through penetration tests, softening point, rotational viscosity, performance
grade (PG); before and after short-term aging (RTFO), and multiple stress creep recovery
(MSCR). The second stage corresponded to the mechanical analysis of the mixtures through
tests of tensile strength, susceptibility to moisture, resilience modulus, dynamic modulus,
fatigue, and permanent deformation; in the third stage an analysis of circularity was carried out
and in the fourth stage a comparative study was carried out analyzing the cost of production of
these. The results showed a rejuvenating effect of SSFA and it was used as a modifier of
recycled asphalt mixtures with 40% RAP in levels of 0, 3 and 5%. The addition of RAP
improved the resistance to permanent deformation and the SSFA improved the fatigue
performance of the recycled mixtures at the tested grades. The recycled asphalt mixtures
presented the highest circularity indexes. The incorporation of accruals increased as accrued
SSFA costs did not increase the increase. Therefore, the recycled mixes were more technically,
environmentally and economically viable than the traditional asphalt mix, especially the mix
with 3% SSFA.
