Pothole 101 – Introduction to Potholes and Traditional Pothole-Filling Techniques
Introduction to potholes and pothole-filling techniques. Topics include an introduction on how potholes are formed and a tutorial on how potholes are treated by trained District Department of Transportation (DDOT) professionals, including an overview of the various compounds DDOT uses to fill potholes.
pot•hole n. 1. Holes in the roadway that appear after water infiltrates, and then expands and contracts, underneath the surface. This process weakens the surface material (for example, asphalt), which is further deteriorated as vehicles pass over it. Potholes appear in periods when there are frequent oscillations between below- and above-freezing temperatures.
Traditional Pothole-Filling Techniques
- Cold Mix Asphalt: Cold mix asphalt is a type of material that is used to patch potholes when roadway temperatures are consistently below 32°F. While this material is more malleable that hot mix asphalt (discussed below), it is also more susceptible to deterioration than its hot-mix counterpart.
- Hot Mix Asphalt: Hot mix asphalt is the “preferred alternative for patching operations” according to Federal Highway Administration Report No. FHWA-RD-99-168. Because of its composition, hot mix asphalt has more viscosity than cold mix asphalt and settles, or cures, faster as well. However, it can only be applied in a climate where roadway temperatures are at 40°F and rising.
Due to consistently low temperatures, DDOT is currently utilizing cold mix asphalt to fill potholes around the District. In addition to low temperatures, the agency is also limited by precipitation and cannot fill potholes in the rain or the snow. DDOT crews have patched more than 19,000 potholes as of March 31, a figure that industry professionals think will steadily grow in the days leading up to the start of the agency’s 2014 Potholepalooza campaign.