Volume 39, Issue 2 (March 2011)
Laboratory Evaluation of Stone Matrix Asphalt Mixtures with Polyethylene and Cellulose Stabilizers
This paper deals with the viability of using reclaimed polyethylene (PE) derived from low-density PE carry bags in shredded form collected from domestic waste as stabilizing fibers to evaluate the performance of stone matrix asphalt (SMA). Conventional SMA mixtures were used as reference mixture and were prepared using 60/70-grade asphalt cement and cellulose fibers as stabilizer. The use of PE-modified binder (PEMB) was also investigated as stabilizer in SMA mixtures. The performance of these mixtures was evaluated by conducting draindown, moisture susceptibility test, aging test, rutting test, creep test, permeability test, and fatigue life tests. The PE fibers reinforce the binder system, resulting in the increase in the viscosity of the system. Draindown test results indicated that PE fibers can be effectively used as a stabilizer in SMA to retard draindown of binder and mineral filler. To study the behaviour of SMA mixtures with different additives, mixtures were designed by Marshall and Superpave. Results showed that mixtures designed by Superpave yielded in 0.2 % reduced asphalt content compared to mixtures designed by the Marshall method. From the present study, results indicated that mixtures prepared with PE fibers showed improved performance than reference SMA mixtures with cellulose fibers. Mixtures prepared with PEMB showed improved performance properties compared to mixtures with PE fibers and cellulose fibers.