Resurfacing is the process of covering over existing pavement with a new pavement surface. Total resurfacing is used under the following circumstances:
- It is economically feasible, and practical from the construction standpoint, to leave all or a greater part of the existing pavement in place.
- The existing grade, structural section, and supporting material are of such condition, thickness, etc., as to permit the existing pavement to be covered. Only such unsatisfactory or surplus portions of pavement are either completely removed or partially removed (by burning) as are deemed necessary to bring the grades and cross-sections to acceptable standards.
Partial resurfacing and partial reconstruction are generally used in conjunction with each other in many projects. Considering previously outlined guidelines, reconstruction is done on those portions of existing pavement that do not lend themselves to resurfacing. The final decision as to the proportions of resurfacing and reconstruction is based on maintaining a balance between economy and adequate design. For example, in making a design investigation, extensive resurfacing or reconstruction should not necessarily be required if the existing pavement surface elevations, for a given area, do not conform by a few hundredths of a foot to the City’s design standards.
E 562.1 Design Criteria (for Resurfacing)
In a street where the surfacing has deteriorated, where the crown of the street is excessively high, or where a combination of these two conditions exists, it becomes necessary to resurface the existing pavement. From soil samples and core tests (or other records that indicate the pavement thickness), it can be determined whether pavement failure was due to poor subsoil, inadequate pavement thickness, or a combination of both. If either or both conditions exist, refer to Section E 622, Pavement Design (Structural), and Figure E 421.1. If adding sufficient pavement to provide the required thickness does not result in excessive crown, additional pavement is merely added to the top of the existing pavement. If the additional required thickness to be added would result in. too high a crown, the existing pavement is removed. If there is poor subsoil, a sufficient depth is excavated and replaced by the recommended thickness of select material subbase. In some streets where the existing subsoil provides a good subbase and the existing pavement is of sufficient thickness, part of the pavement is removed by burning; that is, provided that a minimum 4-inch thickness of pavement remains after burning, and that the maximum crown permitted is not exceeded by the addition of the resurfacing.
The minimum desirable thickness of a resurfacing layer should be 2 inches, with 1 ½ inches as an absolute minimum. A small transitional area is permitted to warp or “feather in” from the absolute minimum of 1 ½ inches to a 0-inch thickness at the join.
E 562.2 Resurfacing Over Rails
Some streets have existing rails which are embedded in the pavement within an abandoned railway right of way. These rails should be either removed or covered with asphalt concrete pavement. After re-surfacing, the resulting pavement crown should meet the pavement crown standards as specified by the crown formulas given in Subsection E 621.1, Parabolic Crown Sections.
The desirable minimum thickness of 2 inches or an absolute minimum of 1 ½ inches of pavement may be used to cover the rails. If the resulting crown is too high, the rails and enough pavement should be removed. This area should then be repaved with an adequate geometric and structural cross-section. See Section E 622, Pavement Design (Structural).
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