The City's Street Division incorporates several different techniques used to prolong the pavement life of asphalt and concrete streets. These proactive maintenance actions are crack sealing, seal coating, concrete panel replacement, mud jacking, milling, and asphalt overlays. All pavement management activities will continue until freezing temperatures prevent further implementation.
Concrete Panel Replacement
In certain situations the only rehabilitation for a failed concrete panel is full depth panel replacement. Water intrusion and sub-base deficiency can cause corner breaks, durability cracking at the joints, longitudinal and transverse cracking. When these pavement distresses are severe enough, the only option is removal. This is accomplished by first fracturing the concrete with a impact or guillotine breaker, removing the broken pieces, stabilizing any base problems, adding steel reinforcing rod, forming if needed and finally pouring new concrete.
The street program utilizes three different size milling machines. Used to grind off bumps and tripping hazards from streets and sidewalks. Carbide tipped cutting heads that revolve at a high rate of speed grind off irregular surfaces making a smooth transition between pavement panels.
A surface treatment applied to asphalt streets consisting of spraying an asphalt emulsion road oil at a rate of .35 gallons per square yard from an oil distributor truck. Then a uniform application of 3/8” oil coated limestone rock chips is immediately applied by a self-propelled chip spreader. The aggregate is then rolled as soon as possible by a rubber tired roller, to ensure the adhesion of the aggregate to the binder and pavement surface. This process has multiple benefits in that it seals out water from penetrating the road structure, seals cracks and raveled surfaces of older pavements, provides an anti-glare surface during wet weather, an increased reflective surface for night driving, provides a highly skid resistant wearing course surface and is cost effective.
Some concrete streets need a little more help besides panel replacement, and this involves installing an overlay. After concrete distresses have been identified and repaired, an asphalt paving machine is used to run a “leveling course” over any uneven areas. After which the paver will lay a much thicker, 2” to 3”asphalt mat over the entire street. This method adds structural strength, improved ride ability and adds years to the service life of the pavement.
Voids or holes under the pavement are caused by several different hydraulic actions. Factors are hills, unstable soils, run off from downspouts, deep edging around driveways and sidewalks, etc. This results in pavements that drop below grade and become uneven. To counter this, holes are drilled into the pavement over the void and a flow able mixture of cement, lime fill, water, and binders are pumped in under pressure that fills the void and brings that pavement back up to level grade.