Effect of the addition of kraft lignin from eucalyptus wood in the rheology of a CAP 50/70

ABSTRACT The study and development of new technologies for paving materials has been greatly motivated by the many problems that pavements have faced. Currently synthetic polymers have already taken their place in the market for the efficiency they have presented in several studies and when tested in service. However, this dependence on fossil fuels is of concern, mainly because of the environmental impact resulting from such use. Thus, alternatives based on renewable resources and still taken advantage of industrial processes have gained space. Lignin is a natural polymer, a byproduct of the pulp and paper industry, extracted from wood in the form of a black liquor by various processes, the kraft process being the main and most used. This material has already demonstrated great potential in some researches due to its association with the asphalt binder, mainly because it has antioxidant properties. Thus, this research aimed to verify the effect of the addition of lignin at 3%, 6% and 9% in the rheological properties of a conventional asphalt binder CAP 50/70 before and after the short term aging (RTFO). Conventional tests of penetration, softening point and elastic recovery were carried out in addition to special tests such as rotational viscosity and those performed in the DSR, in order to determine the parameters of the degree of performance, G *, δ and G*/sin δ, in addition to % Rec and Jnr, the latter through the MSCR. It was found that the binders modified by addition of lignin were more resistant to temperature variation, to permanent deformation, but mainly to aging, showing the performance of this material as an antioxidant, especially for the 9% content, although the other contents also have shown superior performance to the pure binder, proving that the use of lignin in general has proved to be viable both rheologically and environmentally when it is associated with the conventional binder.