2018-013 Council Resolution - Laserfiche WebLink

Home Search

A WSB Pavement Management Report Page 113 CONDITION PERFORMANCE ANALYSIS Work history obtained from the City was included in the model to accurately portray the condition of the streets with respect to the year since construction. The three main inputs for the model were chip seal, mill and overlay, and reclamation / reconstruction. Chip seal was treated as a surface treatment and it does not affect the structural capacity of the pavement, while mill and overlay was treated as major maintenance and repair activity since it improves the structural capacity of the pavement. Reclamation and reconstruction were input as new construction. A condition performance analysis was performed to predict the PCI ratings for the roadways that were not inspected this year. WORK PLANNING MODELS Maintenance cost increases considerably with the age of pavement. Thus, implementing a preventative maintenance strategy proves to be both cost effective and appropriate. Preventative maintenance activities such as crack seal, fog seal, chip seal, and micro surfacing are done at a much lower cost compared to preservation actions such as mill and overlay. The main idea behind the preventative maintenance strategy is that applying the appropriate maintenance action at the right time will keep the good roads in good condition at a lower cost. This is often a better strategy than leaving the road to deteriorate over time before performing maintenance. With the application of proper preventative techniques, the pavement life often can be extended from 20 years to up to 50 years, provided the maintenance is done at the correct time frame. In PAVER, Preventive Maintenance involves crack seal, patching, and joint seal, along with surface treatments such as chip seal, fog seal, and micro surfacing. The critical condition index used was 70 PCI, which is the threshold that mill and overlay, surface reconstruction, reclamation, and complete reconstruction or new construction will be carried out. Using PAVER, the funding level needed to maintain the current weighted average PCI can be predicted. This dollar budget will continue to expand if a pavement management plan is not implemented. A good pavement management plan will budget for preventative maintenance to maintain the pavements in good condition, and preservation to improve the structural capacity of the existing roadway. Figure IVb shows the pavement condition over a course of 20 years, with a variable annual budget available. Figure IVc shows the budget required to maintain various PCI levels for the pavements, including the weighted average PCI of 71.32 at the time of inspection, with no condition tolerance. These scenarios include maintenance activities listed above to be performed, which are Preventative Maintenance, Preservation and Reconstruction. These models also accounted for an inflation rate of 3%. Preservation was set to only be done when the PCI ranges from 70 to 100, when the roads are still in adequate condition. Re -planning of projects was set to every 3 years after recommended maintenance activities were performed since routine inspection and planning help to keep track of the condition of the streets thus appropriate maintenance can be applied.