The main purpose is to evaluate the performance of asphalt regarding resilient modulus and fatigue curve.The asphalt was produced with two wastes, reclaimed asphalt pavement (RAP) and recycled concrete aggregate (RCA), using the technique of warm mixtures. The evaluation includes, based on these parameters, the thickness differences in the design of asphalt layer for each mixture. Five asphalt mixtures were produced with incorporation of RAP and RCA, in different gradation fractions (fine and/or course), without adding any natural aggregate. In view of the aim of the article, the mixtures were evaluated through tests of resilient modulus and fatigue life, in order to support the design, establishing the necessary thickness to meet traffic demands of each mixture. The design was performed using MeDiNa software. Among all results, it is highlighted that asphalt binder content is the component that exerts the greatest influence on the resilient modulus of the mixtures. As for fatigue, in addition to the binder content, the possible anchoring of the asphalt binder in the pores of the RCA may have favored the performance of the GARC_MRAP mixture. Still, all mixtures with RAP, both in fine or course fraction, resulted in lower coating thicknesses compared to the REF, for the same load request, with better performance of the GARC_MRAP mixture produced with 100 % waste material and incorporation of only 3.1 % neat binder.
Resumo: Durante a evolução dos procedimentos de dosagem de misturas asfálticas, diversas formas de compactação de amostras vêm sendo desenvolvidas, podendo ser realizada através de impacto, amassamento, vibração ou rolagem. O método de dosagem mais difundido mundialmente é denominado método Marshall, que faz uso da compactação por impacto. A partir dos anos 90 foi desenvolvido o método Superpave, sendo a forma de compactação por amassamento a principal contribuição desta nova sistemática. A presente pesquisa avalia a influência do método de compactação nos parâmetros de dosagem e no comportamento mecânico de misturas asfálticas (RT e MR). Foi realizada a dosagem de duas misturas asfálticas com os mesmos materiais e granulometria e, em seguida foram moldados corpos de prova cilíndricos utilizando dois tipos de compactação; impacto e amassamento. Os resultados apontam para a redução de 0,5% do teor ótimo de ligante das misturas asfálticas compactadas por amassamento, no compactador giratório Superpave, em comparação com as misturas compactadas por impacto no compactador Marshall. As duas misturas apresentaram valores semelhantes quanto aos parâmetros de RT e MR, sendo que a mistura compactada através do compactador Superpave apresentou menor RT e maior MR do que a mistura compactada no compactador Marshall, possivelmente pelo menor teor de ligante, efeito este positivo do ponto de vista de deformabilidade da mistura.Palavras-chave: Dosagem, Compactação, Marshall, Superpave, Comportamento mecânico.
Abstract:The present research evaluates the influence of the compaction method on the dosage parameters and the mechanical behavior of asphalt mixtures (tensile strength ratio and resilient modulus). Two asphalt mixtures were produced with the same materials and gradation, and then cylindrical specimens were molded using two types of compaction; impact and kneading. The results point to the reduction of 0.5% of the optimum binder content of the compacted asphalt mixtures by kneading in the Superpave gyratory shear compactor in comparison to the impact compacted mixtures in the Marshall compactor. The two mixtures presented similar values for the tensile strength ratio and resilient modulus, and the compacted mixture in Superpave gyratory shear compactor presented lower tensile strength ratio and higher resilient modulus than the one that is compacted in Marshall compactor, a fact that is positive to deformability of the mixture.
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