COMPARATIVE STUDY OF THE EFFECTS OF MODIFIED ASPHALT PAVEMENT USING NANO AND POLYMERS

The global demand for bitumen has increased dramatically recently in spite of its complex production process, which has led scientists to use additives such as polymer materials or nanomaterials to develop bitumen's rheological and mechanical properties. The scope of this research is studying the improvements in rheological properties of enhance enhanced bitumen by Nano-materials or polymer-materials then and it is concerning concerned with the effect of this these additives on Marshall Mix Design and the optimum bitumen content in the asphalt mixture. In this research, two additive materials were used with ratios 1,3,5,7, and 9 % by the weight of bitumen. Materials used were Styrene- Butadiene-Styrene (SBS) as a polymer-material and kaolinite Nano-clay as a Nano-material. Kinematic Viscosity Test, Degree of Penetration Test, Flash Point Test, and Softening Point Test were conducted to evaluate the improvements of enhance bitumen properties. For all mixtures, Marshall Mix Design was conducted to investigate the effects of additives on the optimum bitumen content. After that, indirect tensile strength was conducted to evaluate the improvements of modified asphalt mix. Also, Scanning Electron Microscope (SEM) was conducted to study the distribution of modified agents in bitumen. Test Results were obtained and analyzed. The findings indicate that the incorporation of kaolinite Nano-clay and SBS as modifying agents for bitumen enhances its rheological characteristics. At a concentration of 9%, kaolinite Nano-clay and SBS reduce penetration by 23% and 35%, respectively. Furthermore, SBS contributes to a 55% increase in softening, whereas kaolinite Nano-clay results in a 29% increase. The flash point is elevated by 8% with kaolinite Nano-clay and by 5.5% with SBS, while viscosity experiences a 4% increase for both modifiers. The utilization of these enhanced bitumen agents in asphalt mix design significantly influences nearly all properties of the Marshall Asphalt mix design, with the exception of stability, which exhibits the most pronounced effect. Additionally, the study identifies a mathematical relationship between the proportion of additives and the bitumen content within the asphaltic mix.