Analysis of asphaltic binders modified with PPA by surface techniques.

Area of Science:

• Materials Science
• Chemical Engineering
• Civil Engineering

Background:

• Asphalt binders are crucial in road construction.
• Modifying asphalt binders can enhance performance.
• Polyphosphoric acid (PPA) is a potential modifier.

Purpose of the Study:

• To investigate the structural and mechanical effects of PPA on asphalt binders.
• To evaluate the interaction between PPA and asphalt binder components.
• To assess the impact of PPA on binder-aggregate adhesion and surface properties.

Main Methods:

• Fourier-transform infrared spectroscopy (FTIR) to analyze functional groups.
• Contact angle measurements to assess binder-aggregate adhesion.
• Atomic force microscopy (AFM) to evaluate surface mechanical properties (stiffness, elasticity).

Main Results:

• FTIR confirmed strong interactions between PPA and oxygenated species in the binder.
• Contact angle measurements showed PPA content affects binder-aggregate adhesion.
• AFM revealed that 1% PPA modification resulted in lower surface stiffness compared to unmodified binder.

Conclusions:

• PPA significantly interacts with asphalt binder functional groups.
• PPA modification influences the adhesion properties of asphalt binders.
• PPA addition can alter the surface mechanical characteristics, specifically reducing stiffness, of asphalt binders.