Recycled Polymers for Use as Bitumen Modifiers

Abstract

The volume of waste polymer being produced continues to rise. Disposal is difficult and waste exceeds acceptable levels. The purpose ofthe research is to examine the possibility of incorporating waste polymer into bitumen as a modifier. The aim was to find recycled polymer modified binders that would be similar to proven modified binders or that would augment the properties of 100 penetration grade bitumen. A wide range of recycled polymers was tested including polyethylenes, polypropylenes, polyetherpolyurethane, ground rubber and truck tyre rubber. Tests included viscosity, penetration, softening point, ageing and rheology. Stiffness tests on samples of bituminous mixes made using a selection of binders also formed part of the research programme. Although stability problems were evident with some recycled modified bitumen some cases were found to be successful. The blend with 3% low density polyethlyene substituted for 1% sytrene butadiene styrene had similar properties to that of Polyflex 75 although it had lower stiffness. The most impressive was a combination of low density polyethylene, bitumen and ethyl vinyl acetate.

Study of recycled polyethylene materials as asphalt modifiers

“…It is not surprising that researchers have been very interested in incorporating waste polyethylene into asphalt pavements, as a modifier (Hinislioglu and Agar 2004;Edwards 2003;Panda and Mazumdar 2002;Murphy et al 2000Murphy et al , 2001Yousefi et al 2000;Morrison et al 1994;Liang 1993;Little 1993) or aggregate replacement (Zoorob 2000). However, using waste polyethylene as a modifier in hot-mix asphalt can be quite complicated.…”

Influence of Polymer Type and Structure on Polymer Modified Asphalt Concrete Mix

“…(Berthelot et al, 2003;Krishnan and Rao, 2001). Murphy et al (2001) modifi ed asphalt binder using recycled polymers like polyethylenes, polypropylenes, polyetherpolyurethane and rubber. The performance was evaluated by measuring viscosity, penetration, softening point, aging and rheology.…”

Rheology of waste plastic fibre-modified bitumen

“…Khalid et al (1998) showed the correlation between the rheological properties of the binders in terms of the complex modulus (G * ) and the phase angle (d). Murphy et al (2001) studied recycled waste polymers for use as modified binders. Salab and Suparna (2000) reported that the recycled plastics modified mixes containing polypropylene (PP) and LDPE had better durability and fatigue life as compared with unmodified asphalt mix.…”