What type of material can be used as an additive in asphalt to improve performance?

The use of crushed glass as an additive in asphalt is beneficial for several reasons. Crushed glass can enhance the performance of asphalt by improving its durability and reducing the likelihood of cracking. When incorporated into asphalt mixes, crushed glass can help fill voids in the aggregate, thereby contributing to the overall strength and resistance to wear of the pavement.

Additionally, using crushed glass is an environmentally friendly practice, as it recycles a material that would otherwise occupy landfill space. The glass must be processed correctly to ensure that it meets the necessary specifications for size and cleanliness, making it suitable for asphalt applications. Moreover, incorporating it into asphalt can improve the skid resistance of the surface, which is crucial for safety.

The other materials listed do not offer the same properties or benefits when used as modifiers in asphalt. Sands from beach sources, while potentially usable, do not have the same recycling benefits or performance enhancement properties as crushed glass. Granite aggregates are typically used as the primary aggregate in asphalt mixes but do not function as additives to improve performance in the way that crushed glass does. Wood fibers can have some applications in asphalt, but their effectiveness in performance enhancement is not as widely recognized or utilized as that of crushed glass.