Comparação de desempenho de mistura SMA efetuada com asfalto modificado por borracha utilizando agregados do município de Alegrete e concreto asfáltico

Abstract

The objective of this work was to analyze the performance, through the properties of modulus of resilience and tensile strength of samples of asphalt mixtures of type SMA (Stone Matrix Asphalt), or made of aggregates of the Municipality of Alegrete, following AASHTO MP 8-02 / 12.5mm requirements. To assist in this analysis, considerations from the references on the MR / RT relationship were used. First the aggregates (Los Angeles abrasion, absorption and specific weight) were characterized and then, with these stone materials, molded SMA specimens with rubber asphalt, mixed with DNIT stipulated particle size (Range C) using the same type of binder. asphalt and samples extracted from an asphalt plant, located in the city of Caçapava do Sul and operated by the Company LCM Construção e Comércio, classified in DNIT C-strip and with CAP 50/70. Marshall dosing was employed in the volumetric characterization of the mixtures to determine the optimal content of the designed mixtures. After these steps, the performance of the SMA was compared to the two other mixtures under study, and also to the results obtained by Junges (2017) in the RT and MR tests applied to the mixed and molded asphalts in the laboratory (framed in Strip C using 50/70 and aggregates from the same deposit as the other types of asphalts elaborated in this work), thus revealing the real improvement in their use. Regarding the runoff, the SMA mixture with rubber asphalt proved to be optimal according to the Schellemberg test, governed by EN 12697-18. For tensile strength, the values for SMA mixtures were lower than those for mixtures in the “C” range. For the MR / RT ratio, which indicates durability in asphalt mixtures the results indicate better SMA mix performance.