Effect of Bentonite Incorporation on the Physical and Rheological-Properties of Polymer Modified Bitumen

The finding indicate that PMB provides superior performance compared to standard binders yet its Storage-Stability together with its rheological properties face difficult challenges. The study demonstrates how bentonite affects the rheological and physical characteristics of PMB materials. Bentonite was added at 0, 2, 4 and 6 percent by weight of binder. The standard testing procedures is used to evaluate the modified binders through penetration, softening, rotational viscosity and Storage-Stability testing. The results demonstrate that bentonite changes the behavior of PMB materials. The penetration testing showed a decrease from 62 to 42 (0.1 millimeter) at 6% bentonite which resulted in a stiffness increase of approximately 32%. The Softening-Point increased from 58 degree celsius to 70 degree celsius which results enhanced thermal resistance. Rotational viscosity at 135 degree celsius increased from 1800 to 3300 mPa.s, showing greater resistance to flow at high temperature. Storage-Stability also improved markedly, with the Softening-Point difference reducing from 6.0 degree celsius for the control PMB to 1.6 degree celsius at 6% bentonite. Based on performance and workability, 4% bentonite was found to be the optimum content. The study shows that locally available bentonite can be used as an effective and economical modifier for enhancing PMB performance.