The viscoelastic properties of polymer‐modified asphalts

The linear viscoelastic properties of one family of base asphalts, unmodified or modified by the simple addition of an elastomer or by further in-situ crosslinking, have been investigated. The time-temperature superposition principle was shown to be valid for the base as well as for the modified asphalts. The addition of the elastomer styrene-butadiene (SB) copolymer increased drastically the storage modulus and the elastic character of the asphalts. The thermal susceptibility of the polymer modified asphalts was considerably reduced and this combined with an increased resistance to deformation (larger complex modulus) suggests much better performances for road applications. The chemically modified asphalt containing 3% SB showed similar viscoelastic properties as the physical blend containing 6% SB. On a etudie les proprietes viscoelastiques lineaires d'une famille d'asphaltes de base, non modifies ou modifies par simple ajout d'un elastomere ou par reticulation in situ. On montre que le principe de superposition temps-temperature est valable autant pour les asphaltes de base que pour les asphaltes modifies. L'ajout du copolymere elastomere de styrene-butadiene (SB) augmente considerablement le module d'emmagasinage et le caractere elastique des asphaltes. La susceptibilite thermique des asphaltes modifies est grandement reduite ce qui, si l'on tient compte egalement de la resistance accrue a la deformation (module complexe plus grand), suggere de meilleures performances en vue d'applications sur les routes. L'asphalte modifie chimiquement contenant 3% de SB montre des proprietes elastiques comparables au melange physique contenant 6% de SB.