The City through the Engineering Department and Public Works use a number of pavement management techniques to treat and maintain the City’s street network.
Joint & Crack
Joint & Crack sealing is usually a first defense against pavement deterioration and is typically done to newer roads with small areas of deterioration. In the joint & crack sealing process, sealant is applied to cracks to prevent intrusion of water and incompressible materials into cracks to prevent accelerated deterioration. The City currently undertakes an annual program through Public Works for this technique to repair streets.
Hot-in-place recycling allows crews to recycle one inch of surface while adding one inch of new asphalt to create a drivable, long-lasting roadway. The City currently does not use the Hot-in-Place Recycling technique to repair streets, as there are very limited number of streets which are candidates for this treatment method.
Micro surfacing is sealing mixture of fine aggregate, polymer-modified emulsion, mineral filler and water. Micro surfacing extends pavement life and provides a fast dry time to ensure the roadway is quickly usable. The City currently uses this technique in extending the longevity of the City asphalt major streets, as these streets carry the majority of the City’s traffic.
Asphalt Milling and Overlay
Mill and overlay consists of milling off the top portion of the street and replacing approximately 2 inches of the surface. This technique extends the life of the road in a more cost-efficient manner than a complete reconstruction. The City is looking to use this technique in the coming years on various asphalt streets, in which the base material (rock portion of the road) has not exceeded failure.
Reconstruction is the most expensive of the rehabilitation methods. This technique consists of removing and replacing the existing roadway, road widening, curb and gutter, storm systems, and performing any needed subgrade modifications. The City is limited on funding and currently does not use this technique at this time, however there are several streets which are candidates for this technique
Pavement Condition Index
During street surveys conducted by City, a Pavement Condition Index (PCI) is calculated for each segment. A segment is typically a residential block in length. PCI range between 0 and 100; with a PCI of 0 would correspond to a badly deteriorated pavement with virtually no remaining life and a PCI of 100 would correspond to a pavement at the beginning of its life cycle.
- PCI is measured between 0 and 100; no street is ever truly perfect. Therefore, 98 is the highest rating the City uses.
- The PCI helps to determine the appropriate maintenance method for each street segment.
- The PCI also helps to determine a deterioration curve for long-range budget forecasting.
- To establish the deterioration curve, one-third of the City is looked to be evaluated each year.
City staff strive to have the following average network PCI’s be maintained within the City:
- Arterials – 90
- Collectors – 85
- Residential – 80