Agenda - Council - 03/13/2001 - Laserfiche WebLink

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BACKGROUND Routine maintenance is the most economical method for safeguarding the public investment in bituminous paved streets. The bituminous street surface weakens as a result of sunlight ,txposure, precipitation, fi'eeze/thaw cycles and traffic loading. As a result, the asphaltic components of the bitmninous becomes brittle and susceptible to cracking. Once water is able to penetrate surface cracks into the road base, pavement deteriorates at an accelerating pace. To avoid this rapid deterioration, it is the acknowledged goal of the City to address the maintenance needs of its street system on a periodic basis. Table 1 provides the history, quantities and conditions of the pavements proposed for the 2001 Street Maintenance Program. The 2001 program consists of sixteen individual projects. Eleven projects, which include 14.3 miles of City streets, will receive a sealcoating preceeded by sealing of cracks which exceed one-quarter inch. Five projects, covering 4.5 miles of street, xvill receive a one and one-half inch bituminous overlay of the existing bitumious pavement. The goal of sealcoating is to restore the imperviousness of the pavement. Eliminating water and oxidation retains the flexibility of bituminous pavement. Sealcoating also adds skid resistance as a secondary benefit. Unlike sealcoats which preserve the flexibility of the bituminous, an overlay prov;:~tes additional strength to the pavement structure as well as a like new surface. Each project has been delineated so as to include streets of like constuction and condition and lots of similar size. Often, projects are delineated by individual subdivision however, where subdivisions have been found to have similar pavement ratings and histories, and also have approximately the same amount of street surface area per assessed unit, these subdivisions have been grouped together into a single project to reduce administrative costs. The streets scheduled for maintenance are illustrated in Exhibit A. All streets proposed for the program have received a preliminary survey by the City Engineer and Public Works Supervisor. A post winter survey will be conducted prior to awarding bids in June. Appropriate project adjustments will be made if any of the scheduled pro jr ,:ts are deemed to be inappropriate for sealcoating due to advanced deterioration. PROJECT QUANTITIES AND COSTS Table 2 includes a listing of street lengths and pavement areas for each crack seal/sealcoat project. Estimates are also provided for crack filling material application rates and City Public Works Department time necessary to provide the patching and preparatory work prior to the crack filling and sealcoating work. Both the sealcoating and crack filling operation will be applied by a contractor selected through the competitive bidding process. Previous years low bid and estimated 2001 unit prices for sealcoating and crack filling are as follows: Sealcoating Crack Filling Program S/Sq. Yd. S/Lb. 1991 Actual 0.292 0.92 1992 Actual 0.350 0.833 1993 Actual 0.348 0.70 1994 Actual 0.315 0.699 1995 Actual 0.453 0.739 1996 Actual 0.453 0.72 1997 Actual 0.357 0.696 1998 Actual 0.355 0.60