INFLUENCE DU PLASTIQUE RECYCLE DE TYPE POLYPROPYLENE SUR LES CARACTERISTIQUES DU BITUME ET DE LENROBE BITUMINEUX

Asphalt is the most widely used product in the construction of flexible pavements. The purpose of this study is to evaluate the feasibility of incorporating recycled polypropylene plastic into bitumen to obtain modified asphalt to manufacture modified asphalt mixes that offer better properties than conventional asphalt mixes. A type of asphalt mix has been studied, a semi-grained asphalt concrete (SGAC14). Conventional asphalt mixes as well as asphalt mixes containing 2% and 4% of the polypropylene dosages were manufactured. For all the tests carried out, the performance was evaluated according to five criteria: 1) improvement of the rheological properties of the bitumen (ring balls, penetrability, softening point, ductility) 2) suitability for compaction with the gyratory shear press (GCP) 3) Water resistance 4) rutting resistance and 5) the Marshall Trial. The experimental results showed, among other things: an improvement in the rheological properties of the modified bitumen for the respective polypropylene assays of 1%, 2%, 3%, 4% and 5%. For these assays, respectively, penetrability decreased by 29%, 37%, 42%, 74%, and 90% the temperature of beads and rings increased by 0.73%, 2.94%, 5.5%, 6.24% and 9.17% the springback increased by 13.82%, 21.40%, 5.69% and 4.07%. . The modified asphalt mixes with 2% and 4% polypropylene compact better than the reference asphalt at 80 gyrations with respectively 5.5% and 5.1% voids we have 6.1% voids for the reference asphalt. An increase in water resistance for polypropylene dosages at 2% and 4% respectively the latter offer a variation in simple dry compressive strength of 4.84%, 22% and a variation in compressive strength after 7 days of immersion in water of 8.53%, 19.5%. Improved rutting performance of modified asphalt mixes: The SGAC14 class 0 reference asphalt mixes are upgraded to a class 1 and class 2 SGAC0/14 for 2% and 4% polypropylene dosages respectively. Modified asphalt mixes give the best Marshall stability. Overall, the possibility of incorporating polypropylene into SGAC14 type asphalt has been proven.