05/09/2005 Council Packet - Laserfiche WebLink

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• • • EXTENDING PAVEMENT LIFE BY SPECIAL MAINTENANCE ACTIONS Cities normally engage in periodic special maintenance activities to extend the life of a roadway. These special maintenance actions are defined as sealcoating, overlays or similar actions that are anticipated to last several years and be cost effective. Sealcoating includes pre - sweeping and filling of all cracks in the pavement. A layer of emulsified (liquid) asphalt is applied uniformly across the pavement surface. This is followed by a uniform cover of traprock chips. Sealcoating creates a surface seal to the existing pavement, which provides additional support for traffic loads, and protection from weather conditions. Overlaying includes patching, pothole filling, and crack filling to the existing pavement. This is followed by the placement of bituminous wearing course over the entire surface. For roadways that have curb and gutter, it will be necessary to perform some milling along the curb lines to match the overlay to the grade of the existing gutter. Overlays provide a structural improvement to the roadway. Reconstruction includes the complete removal of the existing pavement and aggregate base course. The roadway will be replaced with the City street standard of a minimum 32 -foot width (back of curb to back of curb) bituminous road with concrete curb and gutter. The pavement section will consist of a minimum 7 -ton design which is 1 V2" of bituminous wearing course, 2" of bituminous base course, and 8" of Class 5 aggregate base course. Reconstruction brings the pavement to an absolute 100 (perfect condition) rating. In order to maximize the life cycle of the pavement at minimum maintenance cost, the proper maintenance actions need to be undertaken at the optimum time. A proposed schedule for these special maintenance actions is as follows: Ave of Roadway Maintenance Action 5 — 7 years first sealcoating 10 —14 years second sealcoating 15 — 21 years third sealcoating 14 -137-