Desenvolvimento de misturas asfálticas contendo material fresado e ligante asfáltico modificado com grafite

Abstract

In Brazil, the study and development of modified asphalt mixtures are justified due to the scarcity of raw materials and the high number of pathological symptoms identified on the highways. Within this context, the development of new asphalt mixtures is a subject that arouses great interest, but requires further research. The general objective of this research was to verify the technical viability of using milled material and graphite-modified asphalt binder as a component of asphalt mixtures. It presents and discusses results regarding the mechanical behavior of asphalt mixtures produced simultaneously with recycled material and modified binder using commercial graphite and comminuted in a high-energy mill. In order to achieve the specific objectives of this research, in addition to the characterization of the tested materials (waste and graphite), ten asphalt concrete compositions were produced, namely: CA-REF110, CA-REF120, CA-GRAF210, CA-GRAF220, CA-GRAF310 , CA-GRAF320, CAGRAFC410, CA-GRAFC420, CA-GRAFC510 and CA-GRAFC520 that were subjected to static indirect tensile strength and modulus tests. The mechanical resistance tests showed a superior behavior in the compositions produced simultaneously with recycled material and binder modified with comminuted graphite in the order of 31.86% and 19.81%, followed by the behavior of the mixtures produced with recycled material and binder modified with commercial graphite in the order of 66.56% and 84.69% compared to conventional mixtures. In the evaluation of the resilience modulus, the mixtures CA-GRAF210, CA-GRAF220, CA-GRAF310 and CA-GRAF320 presented superior resilience modulus in 9.55%, 12.76%, 17.36% and 17.18%, respectively, compared to conventional concrete. While the mixtures CA-GRAFC410, CAGRAFC420, CA-GRAFC510 and CA-GRAFC520 showed an increase of modulus of resilience in the order of 20.77%, 18.39%, 25.39% and 26.74% compared to the reference compositions, thus constituting a strong instrument to provide improvements to the road sector in the country. Therefore, the results of the mechanical tests showed a positive performance of the modified asphalt mixtures. This conclusion contributes to confirm that the use of RAP in asphalt compositions can be an alternative to conventional aggregates for the production of asphalt mixtures.