Properties of asphalt-rubber binders related to characteristics of the incorporated crumb rubber

Abstract

The behavior of asphalt binders modified with recycled crumb rubber depends on several factors, such as: rubber contents and type, temperature and time employed during the digestion process. This paper shows the results of a series of tests performed on asphaltrubber produced via the wet process. The tests included standard penetration, softening point, Brookfield viscosity and resilience. The results show that the limiting variable in the digestion process is the Brookfield viscosity. The influence of rubber type occurred especially in terms of Brookfield viscosity and softening point. There was a decrease in these properties for the asphalt-rubber binders produced with crumb rubber obtained by cryogenic process. Besides, the results show improvements in the modified binders properties, in terms of softening and resilience, when higher rubber content, temperature and digestion time are used.