What color change occurs when an emulsified asphalt breaks?

• A. Brown to black
• B. Remains brown
• C. Turns clear
• D. Color changes from brown to black

Answer: (D)

When an emulsified asphalt breaks, the water and asphalt separate. The emulsion is a suspension where tiny asphalt droplets are dispersed in water with surfactants to keep them apart. If it begins to break, the water drains away and the asphalt droplets coalesce into a continuous film. The material that remains is essentially pure asphalt, which is dark, so the appearance changes from a brownish, water-filled suspension to a deep black color. This color shift is a visual cue that the emulsion has broken and is no longer delivering the intended coating until it’s remixed or used promptly.