What role do nanoparticles play in modifying bitumen?

Nanoparticles, such as nano-silica, nano-clay, and nano-titanium dioxide, enhance bitumen by improving mechanical properties, thermal stability, and resistance to aging. Due to their high surface area and reactivity, nanoparticles can reinforce the bitumen matrix, leading to increased stiffness, improved rutting resistance, and reduced oxidative aging at relatively low additive concentrations.