 | What type of projects & services are provided? |
| What is "seal coat" (chip & seal)? |
| Why is asphalt overlay necessary ... ? |
| Dust control is ... ? |
| Advantages to filling cracks in roads... |
January through March: Snow and ice control, bridge
repair and replacement, culvert replacement, road graveling, materials and
project bidding, equipment and vehicle purchasing, prepare weed control bids,
pothole patching, crack sealing asphalt roads, street sweeping, miscellaneous
concrete repair work (curb/gutter/sidewalk), vehicle and equipment repairs and
preventive maintenance, and project planning.
April through June: Culvert replacement, culvert cleaning,
road graveling and grading, crack sealing asphalt roads, preparing various
roads for maintenance overlay, miscellaneous concrete repair work
(curb/gutter/sidewalk), minor bridge repairs, pothole patching, street sweeping,
dust coating various roads, cattle guard installation and cleaning, vehicle and
equipment repairs and preventive maintenance, and project planning.
July through September: Culvert replacement, culvert cleaning, road graveling
and grading, cattle guard installation and cleaning, preparing various roads for
maintenance overlay, miscellaneous concrete repair work (curb/gutter/sidewalk),
minor bridge repairs, pothole patching, weed mowing, brush removal and tree
cutting, street sweeping, dust controlling various roads, seal coating various
roads, auction used vehicles and equipment, vehicle and equipment repairs and
preventive maintenance, project planning.
October through December: Culvert replacement, road grading and graveling, crack
sealing asphalt roads, minor bridge repairs or replacement, brush removal and
tree cutting, pothole patching, street sweeping, preparation of equipment and
vehicle bids, snow and ice control, vehicle and equipment repairs and preventive
maintenance, project planning.
What is it . . . A chip seal is an application of
liquid asphalt followed with small pea-size chips of gravel.
Why is it done . . . Chip seals are used to retard pavement deterioration,
improve skid resistance and waterproof the old pavement. Roads identified for a
chip seal are in good condition, structurally sound with no major deformations
and do not require an overlay.
When do we do it . . . A chip seal is applied during the warm summer season for
best results. Chip seals are usually applied every five to eight years depending
on the condition of the street.
What can be expected . . . During a chip seal project all vehicles must be
removed from the street so that there are no obstructions. The street is then
swept to remove any loose debris. The chip seal process is then applied. First,
a thin layer of liquid asphalt is sprayed onto the road followed by a machine
that spreads a layer of small pea-sized chips of gravel onto the liquid asphalt.
The street is then rolled with a compactor. Traffic is allowed back on the
street within an hour of the application. After a few days the street is again
swept to remove any loose chips. Depending on the amount of traffic over the
next several months the street may be swept one or more times to completely
remove all loose material.
What is it . . . A pavement overlay is the application
of a layer of hot bituminous paving to an existing paved road that has
deteriorated because by years of wear from traffic and the environment.
Why is it done . . . Mesa County's overlay program is used to restore paved road
surfaces as part of routine maintenance. An overlay adds structural capacity,
riding comfort and skid resistance, which add to the road's safety. Smooth road
surfaces also decrease vehicle maintenance costs and improve fuel economy.
Pavement overlays help reduce traffic noise, which is important in urban
developments. While newly overlaid roads are aesthetically pleasing, roads are
not overlaid to improve appearance.
Pavement deterioration is cumulative. Pavements generally deteriorate at an ever
increasing rate. Factors including, weather, traffic impacts, frequency of
maintenance, etc. all contribute to a road's longevity. The average life of a
paved road in Mesa County is between 18 and 20 years (that is from the time the
road is newly paved to a point where reconstruction becomes necessary).
Routine maintenance . . .is essential. When a paved road reaches about 75% of
its service life (18 to 20 years), deterioration accelerates. If routine
maintenance is not performed restoration costs are four to five times higher.
Once the 75% threshold is reached, reconstruction costs are constant.
When is it done . . . Asphalt overlays are usually done each summer.
What can be expected . . . During an overlay project, residents must remove all
vehicles from the street. If curb and gutter is present the old pavement will be
milled along each edge so that when the overlay is applied the surface of the
new pavement is level with the gutter. The street is then sprayed with a thin
layer of asphalt called a tack coat so that the new pavement will stick to the
old pavement. The overlay is then applied. Traffic should be kept off the new
pavement for at least four hours after it is laid.
Where do we do it . . . Overlays are applied to about 35 miles of carefully
selected rural roads, residential streets, and urban arterial highways each
year. All paved roads are inventoried in a computer
database and evaluated using specialized software. Data is then compiled from
the computer, together with field inspections to determine each year's program.
What is it . . . Mesa County's dust control program
consists of two types of treatments. One, the application of thin layers of
liquid asphalt material followed by an aggregate cover called Dust Control
(Bituminous). Two, a treatment of magnesium chloride called Dust Control
(Magnesium Chloride). The method using asphalt and
aggregate is much more costly and is used on roads having traffic volumes
exceeding 150 vehicles per day. Magnesium chloride is used on roads with lower
volumes of traffic.
Dust Control, Bituminous: When a bituminous dust control is applied to a gravel
road, a thin layer of liquid asphalt is sprayed directly on the gravel surface
as a bonding agent and allowed to cure for at least one day. Then a chip seal
layer is applied. First, a thin layer of liquid asphalt is sprayed on the road
surface followed by a machine that spreads a layer of small inch washed gravel
onto the liquid asphalt. The road is then rolled with a compactor. Later,
another coat of asphalt is applied over the inch chips and a second layer of
smaller inch chips are applied as the final driving surface. The road is again
rolled with a compactor. Traffic is allowed back on the road within an hour of
the final application. After a few days
the road may be swept to remove any loose chips.
Dust Control, Magnesium Chloride: After the road has been prepared for a dust
control treatment, magnesium chloride is applied. Each year previously treated
roads must be retreated with magnesium chloride and as the roads are retreated
dust abatement improves. Magnesium chloride is a great intermediate solution to
reducing dust on low volume roads.
Why is it done . . . Both dust control methods effectively reduce dust and
routine maintenance. The bituminous product is a long-term solution to
controlling dust, but it is expensive and costs nearly 20 times more than
magnesium chloride.
When do we do it . . . Dust control is usually done in late spring and early
summer. Each year a list of roads is identified and a program is developed.
What can be expected . . . During a dust control project all vehicles must be
removed from the street so that there are no obstructions. The street is then
prepared by grading and adding gravel where needed.
Reconstruction:
Once a paved road passes 75% of its service life deterioration accelerates. At
that time the road is damaged beyond routine maintenance repairs and must be
reconstructed. Since reconstruction costs are four to five times higher than
routine maintenance every attempt is made to avoid reconstruction through
routine maintenance.
Street Sweeping:
What is it . . . All arterial roads and collector streets having curb and gutter
are swept as needed with a street sweeper that collects and removes debris.
Other streets, such as residential streets are swept twice annually.
Why is it done . . . Street sweeping is done to reduce dust generated by
traffic, typically after a road has been treated with sand for snow and ice
control. Street sweeping also improves safety by maintaining good skid
resistance. Sweeping also helps keep storm drains clean, streets look better,
and it removes objects that may cause tire damage.
When do we do it . . . Street sweeping is done year-round.
What can be expected . . . When streets are swept all vehicles should be removed
so that the entire street can be swept. Residents are notified with door hangers
when sweeping is planned. Each door hanger states the date and approximate time
we plan to sweep. It should be noted that Mesa County does not have a leaf pick
up program. Leaves raked into streets will not be picked up. Residents living
outside Grand Junction City limits should plan to dispose of their leaves by
other means.
What is it . . . Crack filling is considered a high
priority because it is relatively inexpensive and it provides many times its
value in extending pavement life. Crack filler is an application of hot asphalt
material carefully poured into cracks in the pavement. Cracks are first cleaned
with a blast of compressed air to remove debris followed by the filling
operation.
Why is it done . . . Nearly every asphalt road experiences cracking from the
expansion and contraction of the road surface. These cracks allow moisture to
penetrate into the road subbase causing subsurface failures and potholes.
Sealing cracks in pavement stops moisture from penetrating and prolongs the life
of a road.
When do we do it . . . Crack filler is applied during cooler months when
pavement cracks are widest.
What can be expected . . . The crack filling team moves along the road
controlling traffic and applying the sealer. Only slight disruptions in traffic
flow should be expected.