Polymer modified bitumen

Standard methods of characterisation of bitumen (BIT) and polymer modified bitumen (PMB) do not provide sufficient information. We propose to rely on determination of rheological properties which are much more informative. Along theses lines, we have determined rheology before and after the rolling thin film oven test. The materials studied were BIT, BIT+linear (L), styrene-butadiene-styrene (SBS), block copolymer, BIT+radial (R) and SBS copolymer. The rheological properties of the modified binders are characterised using a dynamic shear rheometer, over wide ranges of temperatures at a fixed traffic frequency of 10 rad s(-1). The SBS block copolymers increase the elasticity of the BIT at high temperatures and contribute to a better flexibility at low temperatures. Polymer modified bitumens have higher resistance to permanent deformation. After aging, the hardening of BIT and PMBs occurred and the elastic response decreases as a consequence of degradation. The determined rheological properties are in agreement with the results of conventional tests.