Preparation Scheme Optimization of Thermosetting Polyurethane Modified Asphalt

Area of Science:

• Materials Science
• Civil Engineering
• Polymer Chemistry

Background:

• Conventional modified asphalt exhibits poor temperature stability, limiting its performance in demanding applications.
• Polyurethane (PU) is explored as a modifier to enhance asphalt properties, particularly temperature resistance.

Purpose of the Study:

• To develop a thermosetting PU-modified asphalt with improved temperature stability and mechanical properties.
• To optimize the preparation technology, PU dosage, and curing agent (CA) dosage for PU asphalt mixtures.

Main Methods:

• Evaluation of different PU modifier types to select the optimal one.
• Design of an L9 (3^3) orthogonal experiment to study preparation technology, PU dosage, and CA dosage.
• Mechanical testing including splitting tensile strength, freeze-thaw splitting strength, and tensile strength ratio (TSR).

Main Results:

• The PU content significantly impacts the splitting tensile strength of PU asphalt mixtures.
• Optimal performance was observed with 56.64% PU and 3.58% CA, prepared using the prefabricated method.
• PU-modified asphalt and mixtures demonstrate high strength, plastic deformation ability, and excellent low-temperature and water stability.

Conclusions:

• Thermosetting PU modification effectively improves asphalt temperature stability and mechanical performance.
• The optimized preparation parameters provide a viable method for producing high-performance PU asphalt.
• The modified asphalt meets stringent standards for use in demanding infrastructure projects.