Study of the mechanical performance of crumb rubber modified bitumen under severe traffic and climate conditions

Description

Study of the mechanical performance of crumb rubber modified bitumen under severe traffic and climate conditions

F. Moreno-Navarro, F.J. Sierra-Carrillo del Albornoz, M. Sol-Sánchez,  M.C. Rubio-Gámez,  R. Pérez-Aparicio,  L. Saiz-Rodríguez

ABSTRACT. After decades of development and numerous experiences around the world, crumb rubber modified asphalt materials has become an interesting alternative to construct more durable and sustainable road pavements. However, and in spite of the technical and environmental advantages that these materials could offer, their use in developed countries such as Spain is still very limited, especially in surface layers and high-volume traffic roads. In recent years, the Andalusian government has applied crumb rubber modified bitumen in the construction of the surface layers of some of the most unfavorable conditions (in terms of climate and traffic) highway sections. In order to know in depth about the mechanical performance of these materials under real severe service conditions, a research project has been carried out in collaboration with Signus and the Laboratory of Construction Engineering of the University of Granada. This paper presents the results obtained until this moment after the study of the evolution of the density, stiffness, fatigue cracking resistance and rheological behavior of cores extracted from these highway sections at different dates during the service life. Based on them, it can be said that the asphalt mixtures manufactured with crumb rubber modified bitumen offer an ageing and mechanical performance very similar to those offered by asphalt mixtures manufactured with traditional high performance SBS modified bitumen, even under severe traffic and climate conditions.

KEYWORDS: Asphalt, crumb rubber, cracking, stiffness, field performance.