Crack treatments consist of placing specialized materials into prepared cracks to prevent water and incompressible intrusion into the cracks and underlying pavement layers, and to reinforce the adjacent pavement.
Types of Crack Treatment Materials
There are several types of materials used for crack treatments ranging from unmodified asphalts and emulsions, to polymer and rubber modified asphalts and specialty chemically curing polymeric materials. Hot applied rubber and polymer modified asphalts are the most widely used materials. Crack treatment materials must have appropriate properties for the climate in which they are used and need to be able to accommodate expected movement. Proper materials are available for use in all climatic areas.
Crack treatment materials can be installed in a range of configurations and with varying preparation methods. Configurations range from filling unprepared cracks and capping with a narrow overband, to specifically designed reservoirs that widen the crack to provide the correct geometry for the expected movements.
Application consists of 3 basic steps– cleaning the cracks, cutting the reservoir if needed, and installing the material. Cleaning is generally accomplished using compressed air. Reservoir cutting is performed using a crack saw or router that can cut varying widths and depths as required. Hot applied products heated to the appropriate temperature in a melter unit equipped with agitation and a temperature monitoring device. The heated material is then pumped into the crack or placed using pour pots or wheeled applicators. Cold applied materials can be installed using pour pots, or other containers. For all installations, cracks must be clean and dry for the best performance.
Properly designed and installed crack treatments have been proven to last between 5 and 7 years.
Properly designed and installed crack treatments have been proven to increase pavement life up to 7 years.