The viscoelastic properties of polymer-modified asphalts

The linear viscoelastic properties of one family of base asphalts, unmodifi ed or modified by the simple addition of an elastomer or by further in-situ crosslinking, have been investigated. The time-temperature superposition p rinciple was shown to be valid for the base as well as for the modified asp halts. The addition of the elastomer styrene-butadiene (SB) copolymer incre ased drastically the storage modulus and the elastic character of the aspha lts. The thermal susceptibility of the polymer modified asphalts was consid erably reduced and this combined with an increased resistance to deformatio n (larger complex modulus) suggests much better performances for road appli cations. The chemically modified asphalt containing 3% SB showed similar vi scoelastic properties as the physical blend containing 6% SB.