“…A large number of polymers have been studied for bitumen modification, including polyethylenes (Jew et al, 1986;Bahl et al, 1993;Fawcett et al, 1999a), polyolefins (Morrison et al, 1994;Fawcett and McNally, 2000a;Fawcett et al, 1999b;Yousefi, 2003), most Introduction to polymer modified bitumen (PmB) extensively styrene homopolymers and copolymers (Airey, 2004;Bahl et al, 1993;Blanco et al, 1995;van Beem and Brasser, 1973;Vonk, 1988, 1992;Lu and Isacsson, 2001;Varma et al, 2002;Vonk and Bull, 1989;Heimerikx, 1993;van Gooswilligen and Vonk, 1986;McNally, 2001a, 2003;Wang et al, 2007;Gonzêlez-Águirre et al, 2009), ionomers (Engel at al., 1991), ethylene vinyl acetate and acrylic copolymers (Denning and Carswell, 1981;Fawcett and McNally, 2001b), rubbers (Fawcett and McNally, 2000b), polymer blends (Fawcett et al, 2002; and many other polymeric materials (Boutevin et al, 1989;Fawcett et al, 2000). More recently, there has been intense interest in the use of recycled or scrap plastic, including tyre rubber crumb to modify bitumen (Singh et al, 2003;Ho et al, 2006;Fang et al, 2008;Fuentes-Audén et al, 2008;Cao et al, 2008;Navarro et al, 2010;Naskar et al, 2010).…”