Estudio experimental del impacto de tres tipos de aditivos en el asfalto ecuatoriano y en una mezcla típica.

Abstract

Aging of asphalt cement from the Esmeraldas Refinery causes durability problems and premature cracking in Ecuadorian pavements. The objective of this degree thesis was to experimentally evaluate the incidence of three additives: a rejuvenator (ReLIXER), a softener (NuMIXER), and a polymer (PGXpand), on the performance of a reference asphalt mixture. The experimental work began with the design of a mixture using the Marshall method, obtaining an asphalt content of 5.55%. Subsequently, 60 briquettes were prepared and distributed across the four study cases, which were subjected to short- and long-term aging. Performance was evaluated through stiffness modulus, permanent deformation under uniaxial cyclic compression at 40 °C, and fatigue tests at 20 °C, using NAT equipment. The results indicated that both ReLIXER and NuMIXER reduced the stiffness of the mixture, whereas the PGXpand increased it. Regarding permanent deformation, ReLIXER and PGXpand reduced susceptibility to rutting, remaining below the 1% threshold, while NuMIXER showed higher susceptibility to deformation. Finally, the fatigue analysis applied solely to long-term aged samples demonstrated that the modified mixtures improved the performance of the reference asphalt mixture under cyclic loading, with NuMIXER standing out by supporting the highest number of cycles before failure. It is concluded that these additives represent a viable alternative to improve performance and counteract the defects of local asphalt