Repair and Maintenance Treatments
City crews prepare the streets for the maintenance treatments by performing:
– Filling of cracks in the asphalt with hot liquid material that dries
and reduces water seepage under the roadway.
- Area or spot asphalt repairs - Using a backhoe or grinder to excavate failed
sections of roadway and then replacing new base material and asphalt.
- Leveling asphalt layers – Paving thin (non-structural) asphalt overlays
to smooth the roadway surface prior to a chip seal treatment (see ‘chip
High quality streets are maintained by using one or more of five different
treatments. Which treatment is applied is determined by the pavement’s
condition and the volume and size of vehicles regularly traveling on the street.
The goal is to provide safe, efficient thoroughfares, while minimizing long-term
maintenance costs. The following treatments are ranked in order of most to
least substantial and expensive repairs.
- Reconstruction – The complete removal of curbs, roadway, and
base followed by the new construction of the street and curb. Usually, the
sidewalks and utilities under the roadway surface are included in this project.
The street is under construction for weeks to months. This treatment is the
most disruptive to the neighborhood. The life expectancy is at least fifteen
years. This is the most expensive treatment usually reserved for the busiest
bus and truck routes and streets in very poor condition.
- Overlay – The edge of the roadway is usually ground down to
the depth of the new paving layer to keep the original flow line or gutter
line intact. The street surface is oiled to help the new asphalt adhere to
the existing layer. A paving machine is used to lay asphalt in lane-width
or wider passes to apply a level and smooth structural layer of asphalt (usually
at least two inches thick). The street is under construction for usually
two different days – one day to grind and one day to pave. The life
expectancy is between ten and fifteen years depending on use and traffic.
This is the next most expensive treatment and used on the busiest streets
where significant bus and truck traffic are present.
- Chip Seal – The surface of the street is coated with a thin
hot temperature emulsion layer containing melted rubber. Small rock chips
are spread over the emulsion and rolled into place. The excess rock chips
are swept clean. Normally, the City covers the chip seal with a slurry seal
to provide a finished look to the street and hold the chips in place. The
street is usually under construction for three different days – one
day to prepare the street, one day to chip seal, and one day to slurry seal.
The life expectancy is seven to twelve years. This is a mid-priced treatment
that is typically used on neighborhood streets.
- Slurry Seal – The surface of the street is coated with a thin
emulsion with liquid rubber and course sand layer that requires up to eight
hours to cure. The street is usually under construction for two days, one
day to prepare the street and one day to slurry seal. The life expectancy
is five to seven years. This is a lower cost treatment used to keep good
condition streets in good condition.
- Crack Seal – Cracks present in the street are cleaned using
high-pressure air to blow out debris. Hot tar material is applied to fill
the crack and smoothed using a squeegee to seal the crack. Sand is spread
over the fill material to allow traffic to drive over the fill without sticking
to it. This treatment extends the life of streets by eliminating moisture
seeping under the asphalt into the base material. The street is usually under
construction for part of a day. The life expectancy is from two to five years.
This is the least expensive street maintenance activity.