Análise do comportamento mecânico de mistura asfáltica reciclada a quente com uso de glicerina como agente rejuvenescedor.

Abstract

The asphalt coating undergoes an aging process due to oxidation of the binder. When it loses its useful conditions, there is the possibility of the pavement being milled, and then reused, receiving the name of RAP, which can be used in new coatings by adding rejuvenating agents that restore the lost viscoelastic properties to the material. Alternative agents have been studied, including glycerin, which is an organic compound with an alcohol function, colorless, odorless, viscous, hygroscopic and non-corrosive. This research aims to evaluate the use of glycerin as a rejuvenating agent of RAP, constituting a real and viable option to act as a precursor of products with high added value. In a first step, the mixture without the incorporation of RAP and without glycerin was evaluated in the laboratory, and another mixture with the incorporation of 30% of RAP and without addition of glycerin, in the second phase, the glycerin was incorporated in the levels of 4% and 6% in blends with 30% RAP. The evaluation of the mechanical behavior was carried out through the tensile strength tests by diametrical compression (RT), resilience modulus (MR), induced moisture damage (Lottman) and wear in the cantabrian test. The results of the RT tests were satisfactory, and superior to that determined by the norm in all compositions. The results for the MR of the mixtures showed an increase both with the addition of RAP (30% RAP and 0% glycerin) and with the addition of glycerin (30% RAP and 4% glycerin, 30% RAP and 6% glycerin) in relation to reference sample (0% RAP and 0% glycerin). The results obtained for cantabrian indicate that the addition of glycerin increases mass loss and the results of induced moisture damage indicated an increase in resistance to the deleterious effect of water with glycerin. Therefore, glycerin is not a suitable material for use in rejuvenation, but can be used as a corrective agent for workability, acting as a surface-active agent, reducing friction at the interface of the aggregates, and to promote increased tensile strength and resistance to the harmful action of water in a mixture containing RAP.