This paper shows the characteristics of several asphalt-rubber binders produced at the laboratory or in a polymer modified binder plant. Their properties fulfil the Spanish specifications for polymer modified asphalt binders.
These asphalt-rubber binders have been used in dense-graded, gap-graded and porous asphalt mixes. The dense-graded asphalt mixes were designed by the Marshall procedure; the gap graded asphalt mixes were designed through a specific surface method; and the porous asphalt mix by a Spanish test which is called “Cántabro” testing procedure. All these mixes are usually employed in wearing courses.
The above-mentioned mixes were tested at laboratory. The performance of dense graded asphalt-rubber mixes includes high resistance to permanent deformations, good results in immersion-compression tests and a long fatigue life. The behaviour of gap-graded and porous asphalt mixes produced with asphalt-rubber is similar to that of the mixes with other polymer modified binders.
According to these results, asphalt-rubber is an excellent binder for wearing courses.