Street Preservation & Maintenance Techniques
Over time, sunlight oxidizes the oils in asphalt, causing the asphalt to become brittle and develop cracks. Cracks in asphalt roadways provide a place for moisture to reach the pavement base and will ultimately lead to more extensive deterioration.
Removal of any distressed areas where the pavement is fractured and broken and is allowing water to weaken the subgrade under the roadway. Various methods are used to remove the distressed asphalt. Once removed new asphalt is placed. These repairs are accomplished prior to the scheduled resurfacing sometimes up to a year in advance.
Pavement Preservation Activities
Pavement preservation activities will improve driving conditions as well as the aesthetics of the roadway. Resurfacing is a multi-step process that usually involves several work crews. Regular and effective maintenance is required to keep the existing road infrastructure operating at a satisfactory level of service. Any efforts to repair and rehabilitate pavements that have deteriorated beyond a certain extent have proved to be costly and time-consuming. Hence, a preventative maintenance system considering cost-effectiveness is the more effective option. Such proactive policies prescribe less-costly treatments for pavement facilities in order to prevent severe deterioration from occurring. Several preservation techniques are used to help maintain the street segments. The following gives a brief outline of our most common type of resurfacing and maintenance activities.
A blend of oil and small aggregate that is applied to the streets. Slurry seal is a preventative maintenance procedure. The construction cost is approximately $1.75 per square yard. Slurry sealing can extend the life of a street by 5-7 years.
A thin surfacing containing polymer modified emulsion and graded aggregate. Can be used for the same applications as slurry seals, but thicker layers can be placed allowing for slight rut filling. Construction cost is approximately $2.50 per square yard. Microsurfacing can extend the life of the street by 7-10 years.
Asphalt Rubber Cape Seal (ARC)
An integrated process, with one road treatment followed by another. It begins with a chip seal, which is the application of liquid asphalt, followed by placement of small rock “chips”. This treatment is followed by a slurry seal (usually 10 to 14 days later). This process gives the strength of a chip seal with the added benefit of a smoother riding surface. Asphalt rubber is used in the asphalt binder, which can be used over cracked pavements and is resistant to reflective cracking. The Asphalt rubber is a blend of asphalt cement, reclaimed tire rubber, and additives. Construction cost is approximately $6.00 per square yard. Rubber Cape sealing can extend the life of a street by 10-14 years
The highest form of street maintenance, overlay involves the placement of a new layer of asphalt, approximately one and a half to three and a half inches thick, on the street. The construction cost to overlay a street is approximately $32 per square yard depending upon the thickness required.
Properly maintained, an overlay can extend the life of the street by 20-25 years although heavily used streets may require more frequent overlays.