Levantamento bibliográfico sobre a influência da adição de óleos vegetais nas propriedades mecânicas de misturas asfálticas recicladas

Abstract

Environmental causes are increasingly gaining prominence worldwide, bringing the need to reduce the use of natural resources. The use of milled material (Reclaimed Asphalt Pavement - RAP) in new asphalt mixtures has gained visibility, because it promotes savings in the use of virgin materials and energy costs. The use of high percentages of RAP, above 30%, will generate asphalt mixtures with high stiffness, making them susceptible to premature fatigue cracking. The addition of recycling agents provides a partial restoration of the RAP properties, making the recycled mix mechanically feasible. Vegetable oils are an excellent alternative recycling agent, because they are rich in unsaturated fatty acids, contributing to reduce the stiffness of mixtures with high content of RAP, besides being environmentally friendly. In this sense, the present work gathered, through a literature review, data on the mechanical behavior of recycled asphalt mixtures with the addition of vegetable oils. The papers were collected using the databases ResearchGate, Scientific Electronic Library Online (SciELO), Portal de Periódicos da CAPES and Google Scholar, prioritizing publications after 2015. For this, an analysis and description of the results obtained by each author was performed, verifying the behavior for the mechanical properties of Marshall stability, resilience modulus, tensile strength, fatigue life, and susceptibility to induced moisture. After that, with the use of scatter plots built for each property, a trend study was carried out seeking to establish relationships between variations in RAP content, oil content, and type of oil used in the mixtures. The results indicate that the use of vegetable oil in recycled asphalt mixtures promotes a mechanical behavior similar to that of conventional mixtures, when added with levels generally up to 10%. For percentages above 10%, it can lead to excessive softening of the recycled asphalt mixtures, thus compromising their mechanical performance.