Repair Cost by Type
The following is the cost associated with the different types of street repair and replacement along with a description. Crack and Chip Seal are methods to maintain streets while reconstruction means the replacement of a street.
Crack Sealing Cost: $2,400 per lane mile
Crack sealing is a short-term, cost-effective way to maintain the life of pavement. It seals the cracks from water intrusion and other damaging factors that could lead to premature sub base failure. The material is made up of crumb rubber and emulsified asphalt for flexibility due to the expansion and contraction of asphalt surfaces. It is applied hot to create a bond with the existing pavement. If a crack seal is covered by a seal coat or a chip seal within a year or two, the life expectancy can more than double. Life expectancy is between 3 -5 years.
Chip Sealing Cost: $18,480 per lane mile
A chip seal is a long-term, cost effective way to maintain the life of pavement. The goal of a chip seal is to correct raveling, seal small cracks, and slow the process of oxidation while providing a new wearing surface. It does not necessarily improve ride quality. Chip sealing is an application of emulsified asphalt and a 3/8” granite aggregate cover. The emulsified asphalt is applied hot. After the hot asphalt is applied to the pavement surface, aggregate is immediately applied over the asphalt. A pneumatic roller is used to compact the aggregate particles in the asphalt. All loose aggregate is swept up and then another coating of emulsified asphalt is applied to seal the surface. Life expectancy is between 8 -10 years.
Seal Coating Cost: $17,424 per lane mile
Seal coating is a short-term, cost effective way to prolong the life of pavement. It protects the asphalt pavement from ultraviolet rays and water, helping to slow the process of oxidation and raveling. The goal of seal coating is to create a waterproof, protective coating that can increase the life of pavement and improve appearance, but not necessarily ride quality. A seal coat is a thin membrane of emulsified hot asphalt application that is generally 1/32” to 1/8” thick. Life expectancy of a seal coat is 3 -5 years.
Milling and Overlay with Partial Full Depth Patching Cost: $165,312 per lane mile
Milling and overlay with partial full depth patching is a long term repair. This type of project is a cost effective way to repair and completely repave a selected street. For a street to be selected for this type of repair it must have at least partial structural strength within the base and sub-base of the asphalt. The process is first completed by patching or selecting areas within the street segment that need full depth repair, milling this section and replacing the removed area with hot mix asphalt base. Once the patching is completed the entire street segment selected will be milled and overlaid with 2" of hot mix asphalt surface course providing a new strong, crack free, smooth driving surface. The life expectancy if the roadway meets structural criteria is between 20-25 years.
Complete Reconstruction of Sub-Base and Asphalt Cost: $285,648 per lane mile
A complete reconstruction is a long term, but extremely expensive repair to the street. It provides a new, strong, crack free, smooth driving surface. It requires removing all old asphalt and failed sub base and replacing and compacting new sub base materials and establishing proper shape and grade of the sub surface prior to placing hot asphalt material. The application of hot asphalt material is placed by large paving machines and pneumatic and steel wheel rollers. The asphalt thickness is generally 6” on residential streets and 8” on primary and secondary routes. The life expectancy is between 20 -25 years.
Concrete Replacement Cost: $49.29 per Linear Foot
Concrete sidewalk, curb and gutter, and cross-pan replacement may be necessary and is usually completed 9 to 12 months prior to a street project. Installing ADA accessible cut outs and surfaces may also be required.
This performance measure also shows the breakout of street and sidewalk repair projects based on the percentage of the total dollar amount expended for each category during the month. Street maintenance follows a sequence starting with concrete replacement followed by patch work and finally mill and overlay. When streets are in better condition a crack or chip seal may be applied to increase the life of the street.
Project categories include:
1) Crack seal, seal coat , and chip seal are grouped together into the minor street repair category
2) Mill and overlay and complete reconstruction are grouped together in the major street repair category
3) All sidewalk work is grouped together in the concrete replacement category
By tracking the cost of each type of project and recording the location in which they were completed, the City can determine the overall annual project scope and assist in how these projects will be selected into the future. The goal is to repair or replace as much street and sidewalk as possible with limited resources. The use of minor repairs like crack sealing, chips seals and selecting only failing sidewalk and curb and gutter sections help extend the life of the existing roadway and concrete structures. With the existing structures being repaired and only sections being entirely replaced our funding resources stretch further throughout the City. To ensure the City provides the best products for its citizens with the funding available the City staff monitor contractor performance on a monthly basis focused on amount of material and labor resources utilized compared to estimates and prior work experience.
In June 2017, the crack seal project launched and is moving quickly through multiple locations. The milling and overlay project and the concrete replacement project are both progressing with multiple roadway sections now being completed. These projects are all on schedule and moving forward without issues.