Agenda - Council - 02/14/1995 - 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 exposure, precipitation, freeze/thaw cycles and traffic loading. As a result, the asphaltic components of the bitumkous becomes brittle and susceptible to cracking. Once water is able to penetrate surface cracki into the road base, pavement deteriorates at an accelerating pace. To avoid this rapid deteri6ration, it is the acknowledged goal of the City to address the maintenance needs of its street systerfi on a periodic basis. Table:!I below provides the history of the pavements proposed for the 1995 Street Maintenance Progrm. The 1995 program consists of individual public improvement projects which have been aggregated by individual subdivisions. Projects 95-01 through 95-08 consist of sealcoating operations which will be preceded by spot repair of isolated failed areas. Also, these projects will have the large working cracks which are between 1/4 inch and one inch wide filled with a rubberized asphalt material prior to sealcoating. Projects 95-09 and 95-I0 consist of placing a one and one-half inch bituminous overlay on top of the existing pavement. The overlaying process, while~ore expensive than the sealcoating operation, adds additional pavement strength and presents a smooth and like new surface. The s~eets scheduled for maintenance are illustrated in Exhibit A. Ail streets proposed for the 1995 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 portions of Projects 94-0t through 94-11 are deemed to be inappropriate for sealcoating or overlaying due to advanced deterioration or insufficient pavement structure. PRO.CT QUANTITIES AND COSTS Table~2 provides a detailed breakdown of street lengths, widths and pavement areas for each sealcoat project. Individual projects have been generally aggregated by subdivision such that the majon'ty of the properties benefitted within each project have similar characteristics. 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 f'flling operation will be applied by a contractor selected through the competitive bidding process. Previous years iow bid and estimated 1994 unit prices for sealcoating and crack filling are as follows: Sealcoating Crack Filling S/Lb. 15o The e~timated construction costs are contained in Table 3. The amount of crack filling material requi{ed is highly variable depending upon the number of cracks in th.e individual pavements. Based!upon previous experience, and a windshield survey of streets iri the 1995 program, the application rate of crack fzlling material was estimated for each project and is contained in Table 2. 1991 Actual .292 0.92 1992 Actual .350 0.833 1993 Actual .348 0.70 1994Actual .315 0.699 1995 Estimate .370 0.83