Modification of Asphalt Cement by Natural Rubber for Pavement Construction

Improvement the quality of asphalt for pavement construction is practical to prolong lifetime of roads. Polymer Modified Asphalt or PMA is one of such improvement by mixing polymers in asphalt. Natural rubber is an interested polymer that can be efficiently used. The distingue quality of natural rubber is its' high satability, elasicity, and fatigue resistance. The aim of the study is to find the appropriate ratio of asphalt and rubber, which can achieve specifications required. The experiments were carried on by adding Ribbed Smoked Sheet (RSS) of 0, 2, 4, 6, 8 andl0% by weight in asphalt and using high shear mixer. Asphalt qualities were investigated in penetration, softening point, penetration index, ductility, torsional recovery, toughness-tenacity, and viscosity. It was found that 6% by weight of natural rubber in asphalt is the most effective ratio to develop low penetration, high softening point, high penetration index, high torsional recovery, and high toughness - tenacity. The road using this mixing rate shows high strength and resistance, whilst increasing of viscosity does not cause the problem in aggregation of asphalt-concrete.