Statistical optimization of crumb rubber modified bitumen performance through material blending analysis.

Area of Science:

• Materials Science
• Civil Engineering
• Chemical Engineering

Background:

• Crumb rubber modified bitumen (CRMB) offers enhanced pavement performance.
• Optimizing CRMB requires understanding blending parameters and material properties.

Purpose of the Study:

• To comprehensively investigate and optimize the performance of CRMB.
• To analyze the effects of blending parameters and material characteristics on CRMB properties.

Main Methods:

• Systematic evaluation of blending temperature, mixing speed, time, and mixer type.
• Assessment of bitumen grade, crumb rubber type, mesh size, and content.
• Chemical interaction analysis using SARA fractions and statistical methods (factorial design, ANOVA).

Main Results:

• Optimized blending at 180°C for 90 min with high shear mixing (2000-3000 rpm) yielded stable CRMB.
• Significant improvements in viscosity, penetration, and softening point were observed.
• Aromatic content inversely correlated with viscosity (r = -0.78); resins and asphaltenes increased stiffness.

Conclusions:

• Performance optimization necessitates controlled blending conditions and informed material selection.
• Developed regression models achieved strong predictive power (R² = 0.85).
• This dual approach supports scalable, efficient, and sustainable CRMB production.