Asphalt binder is a sticky, black substance made from refined crude oil. It is a key component in the production of asphalt, which is commonly used for paving roads, parking lots, and driveways. The binder helps to hold the aggregate materials, like gravel and sand, together, creating a durable surface. This material is known for its waterproofing properties, making it effective in protecting underlying layers from moisture damage. Additionally, asphalt binder can be modified with additives to enhance its performance, such as improving flexibility and resistance to temperature changes, which is important for maintaining road quality over time.