Additives in Modified Asphalt and Bitumen: Implications for Pavement Performance and Rehabilitation

The increasing demand for sustainable and high performance road infrastructure has accelerated the research on additives for bitumen and asphalt modification. This study aims to evaluate global research trends, identify the dominant additives used in pavement applications, and highlight underexplored research areas. A bibliometric analysis was conducted using 3325 Scopus-indexed journal articles published between 2016 and 2025. The dataset was analysed using Scopus Analyzer, VOSviewer, Microsoft Excel and MapChart, while Pearson correlation and Kendall’s tau were employed for statistical assessment of relationship among bibliometric indicators. The findings reveal a strong and growing research interest in additive used in modified bitumen and asphalt, particularly in relation to sustainability, pavement performance and material innovation. The most frequent studied were silica, fly ash, hydrated lime, slag, crumb rubber, and styrene–butadiene–styrene (SBS), with SBS emerging as most extensively explored modifier. However, the analysis also shows the most studies remain concentrated on hot and warm mix asphalt, which cold mix asphalt and bitumen emulsions application are comparatively underexplored. These findings provide a useful reference for researchers in selecting potential additives and identifying future research directions, particularly for sustainable pavement technologies involving cold mix and emulsion applications.