Craze cracking in asphalt primarily arises from differential shrinkage, which occurs when different parts of the asphalt surface contract at varying rates as they cool. This situation can lead to internal stresses that exceed the tensile strength of the material, causing fine cracks to form. It is important to understand that this phenomenon is often the result of the inherent properties of the asphalt mix itself and the conditions during the curing process.
Differential shrinkage can be influenced by several factors such as moisture content, the use of varied materials, and the method of application during installation. When certain sections shrink more than others, particularly in larger areas, this results in the cosmetic cracks often observed as a network of fine lines across the surface.
While uneven application, differential expansion rates, and overexposure to sunlight can contribute to asphalt deterioration, they do not directly cause the specific type of fine cracks known as craze cracking. Uneven application might lead to inconsistent thickness, thereby affecting the wear and longevity of the surface but not necessarily through craze cracking. Expansive forces due to temperature variations may impact asphalt, but this is not the primary mechanism for the narrow cracking observed in craze cracks. Sunlight exposure can degrade the asphalt surface over time, leading to other forms of cracking and damage like r