Avaliação reológica do ligante asfáltico 50/70 modificado com lignina das madeiras pinus e eucalipto.

Abstract

Lignin is a natural polymer and the second most abundant material of the plant kingdom, being able to present different chemical compositions depending on its location in the vegetable, its age and species. This is obtained in large scale as a by-product of the pulp and paper industry and is used as a source of energy by burning in the industry itself, however the surplus is discarded in the environment appearing interest in the search for alternative ways for its application. Because of their antioxidant properties, research on the modification of asphalt binders with lignin is being developed to improve the behavior of asphalt mixtures in order to be more resistant to aging, exhibiting reduced permanent deformations, a longer fatigue life and a lower environmental impact. Thus, this research has the objective of studying the modification of the 50/70 asphaltic binder by two types of lignin, from different species, hardwood (Pinus) and conifers (Eucalyptus), at levels of 3%, 6% and 9%. In this research the RTFO aging procedure, the conventional physical tests of penetration and softening point, the chemical FTIR test and the rheological tests of rotational viscosity, degree of performance (PG), creep and recovery under multiple stresses (MSCR) and linear sweep (LAS). The results indicated the feasibility of the incorporation of lignin to the CAP 50/70 since they increased the life of fatigue, the resistance to the permanent deformations and delayed the aging process, with a positive highlight for the 3% content that presented the best yields of the rheological point of view. In this way the use of this natural polymer is a technically feasible alternative and can also be favorable in relation to the environment to avoid an inappropriate disposal of the material and economic issues by adding commercial value to an industrial residue for the modification of binders.