Work

Quantum chemical insights into molecular interactions within asphalt systems

Year: 2026

Type: article

Abstract: Molecular aggregation significantly impacts the stability, rheology, and durability of asphalt binders. While previous research has mainly focused on asphaltenes, the quantum-scale mechanisms of aggregation for all asphalt components remain unclear. This study uses quantum chemical calculations on 50 asphalt molecules to analyze surface electrostatic potential, π-electron properties, LOLIPOP index, and weak interaction energies to identify favorable aggregation configurations. The findings reveal that π-π interactions drive asphaltene aggregation, resins act as modifiers, aromatics enhance solubility and dispersibility, and saturated hydrocarbons create steric hindrance. Additionally, the length of polycyclic aromatic hydrocarbons and alkyl chains play a critical role in determining intermolecular distance and polarity. SARA fractionation and^1H NMR analysis of four binders show that TH asphalt, rich in π-electron-dense components with long side chains, stabilizes the microstructure, resulting in optimal rheological properties. AFM imaging reveals a honeycomb structure primarily formed by asphaltene-driven aggregation. In summary, this computational-experimental framework elucidates the molecular origins of asphalt aggregation and the distinct roles of SARA components, establishes a clear composition-performance relationship, and provides mechanistic guidance for designing durable asphalt.

Source: Materials & Design

DOI: 10.1016/j.matdes.2026.115489

Authors: Guannan Li, Mengyuan He, Changjiang Dai, Liang He, Tianling Wang, Xin Liu

Institutions: Chongqing Jiaotong University, RWTH Aachen University

Language: English

Topic: Asphalt Pavement Performance Evaluation

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,650