Asphalt Paving / Asphalt Repair / Catch Basin / Drainage Tile / Asphalt Recycling
- Asphalt Resurfacing
- Geotextile Paving Fabric
- Asphalt Milling
- Asphalt Repair
- Catch Basin Repair
- Drainage Tile
- Asphalt Recycling
Typically the winter months of December 20th – March 15th are off-peak for asphalt, concrete and pavement maintenance services. In the Mid-Atlantic market the temperatures historically fluctuate between below freezing and above freezing throughout the winter months. These temperature fluctuations wreak havoc on asphalt and concrete through the constant expansion and contraction of asphalt & concrete substrates from the freeze/thaw cycle.
Our asphalt division is available for all your asphalt repair, recycling, drainage, catch basin repair and paving needs. Our asphalt division handles projects as small as single pot repairs and up to a 3,000 ton resurfacing projects. In addition, our in-place recycling services can not only help you earn LEED points, it can also help you save valuable budget dollars.
For a more in depth review of all our services listed on this page, please visit the specification library in our (hyperlink to pavement page) section of our website.
What is asphalt?
Asphalt concrete, normally known simply as asphalt or (HMA) hot mix asphalt, is a composite material commonly used for construction of pavement, highways and parking lots. It consists of asphalt binder and mineral aggregate mixed together then laid down in layers and compacted.
Types of Asphalt
- 1/4” Surface Mix (Used for resurfacing, not ideal for high truck traffic areas or extreme turns)
- 3/8” Surface Mix (Used for 90% of asphalt resurfacing projects)
- 1/2” Surface Mix/Structural Overlay (Used for high traffic parking lots, medium truck areas, when budgets are tight, and a 2” – 3” full depth patch or mill and replace project is being completed).
- 3/4” Base Mix (Used as a patching binder in 2” – 4” depths and as a base installation over fine graded stone prior to installing a 2” asphalt overlay)
If your parking lot is past the point of no return and is experiencing severe cracking, alligator cracking, rutting, heaving, pot holes or areas of standing water, it is time to invest in an asphalt overlay.
An asphalt overlay usually installs a 2” compacted mat of asphalt with either 3/8” stone or 1/4” stone.
Resurfacing varies on the parking lot surface. For example, if you have an overlay that needs to be performed on a high-traffic parking lot and the lot needs to remain open during resurfacing, we may use a 1/2” mix. We would use this larger mix in the asphalt to reduce power steering marks and possible shoving of the mix in turn lanes while still tender.
Preparation to Ensure the Longevity of the Asphalt Overlay
Pot Holes- Prior to installing the asphalt overlay, all pot holes should be square-cut, excavated to the stone base and repaired with a base mix asphalt (3/4” stone).
Rutting / Areas Of Standing Water / Heaving- Prior to installing the asphalt overlay, all rutted areas and areas of standing water should receive a leveling course to remove surface imperfections.
If a parking lot is very old and has many areas of small puddles or waviness, a 1/4” leveling course should be applied to the parking lot to bring the surface to a 100% level grade.
Any heaved or raised areas should be cut down with a milling head or jack hammer to prevent resurfacing through the new asphalt overlay.
If the heaved area is due to frost, it is advisable to excavate the area to a depth of 18” – 24” and install clean stone to prevent future heaving.
Geotextile paving fabric is the single most cost-effective preparation item that can be installed.
Studies by the Federal Highway Administration have shown, having a geotextile fabric install prior to resurfacing can reduce reflective cracking by 80% over the life of a 15-year overlay.
For less than $0.25 sq ft, you can help extend the life of your overlay to 15 – 20 years without the pavement re-cracking. **If installed in the beginning**
Paving Fabric also provides a moisture barrier preventing water from pumping to the surface from hydrostatic pressure.
Depending on the severity of alligator cracked areas, heaving and rutting, you may want to address the areas with either full depth reclamation (4” – 6” ) and install Binder Asphalt (3/4” stone) prior to installing the fabric or if budgets are tight, mill down 2” and install 2” of Binder asphalt (3/4”) stone.Important Note
Most asphalt overlays are installed improperly and usually do not last 2 years before the cracks resurface into the new asphalt. This is not the fault of the property manager, but rather the contractor. Some contractors, being full aware of the additional services available to strengthen an overlay do not recommend them because they become involved in local or national “price-wars” and do not want their bid to be higher than the others. For instance, if you install a 2” average overlay over alligator-cracked pavement or large cracks, those same cracks will reflect back through the new overlay at an average rate of 1” per year. In effect, after 2 years, your new parking lot will resemble the same crack patterns and areas of deficiencies that the old parking lot had. How would you feel if you just spent $150,000.00 to overlay a parking lot and in 2 years it looks the same as it did prior? You would probably be pretty frustrated. The truth of the matter is that there are several technologies and processes that are available to prevent this from happening; however, finding a contractor who will recommend them will be similar to finding a needle in a haystack.
The Math is simple: 100,000 sq ft parking lot overlay
- Overlay the parking lot without making the necessary upgrades and in 2 years your parking lot will need to be overlaid again. $100,000.00 parking lot, 2 year service life (Cost Per Year / Per Sq Ft: $0.50)
- Crack Seal and Install a Geotextile Crack Retardant Fabric. Service life extended to 15 years. (Cost Per Year / Per Sq Ft: $0.07)
- Do you see why spending an additional $0.20 sq ft up front will save $0.43 sq ft over a 15 yr period?
At minimum, a parking lot needs to be crack sealed prior to installing an asphalt overlay to defer reflective cracking for 3 – 5 years.
Asphalt milling is used to remove ½” – 4+” prior to installing a new 2” asphalt overlay.
Benefits of Asphalt Milling:
- Allows a 6” curb reveal after resurfacing (Some code requirements dictate that there must be a minimum concrete curb reveal to prevent trip & falls)
- Is utilized for efficient removal of damaged asphalt and/or base material to prepare the identified areas for installation of either new sub-base stone or binder asphalt prior to installing the asphalt overlay
- Is extremely effective for drainage correction and surface profiling to remove irregularities
- Is utilized for removal of failed asphalt mix that has hairline cracks prior to installing the asphalt overlay
Asphalt milling will NOT prevent reflective cracking if there is cracks in the base layer of asphalt or if there is vertical movement in the asphalt base layer from unstable subgrade. Some asphalt contractors will lead you to believe milling the surface layer of asphalt in a badly cracked / deteriorated parking lot will prevent reflective cracking.. This is NOT accurate. In some instances, the top 1 ½” – 2” overlay in the past may have cracked from either insufficient thickness for the traffic design (ie: Installing a 1” asphalt overlay in a heavy truck area), the asphalt may have been installed when it was cold and the property compaction was not achieved or the asphalt mix was defective. In these cases, after milling and sweeping the lot, if the base layer does not show signs of cracks, the new overlay will not have reflective cracking (As long as it is installed at the proper thickness for the traffic design). If after milling and sweeping cracks are evident in the base layer of asphalt, the only application to prevent reflective cracking is to install a geotextile paving fabric as mentioned above.
Here is an example after milling where cracks are still present in the base layer of asphalt.
What is a pot hole or alligator cracking and what causes it?
Potholes (sometimes called kettle and known in parts of the Western United States as a chuckhole) are a disruption in the parking lot surface.
Potholes are formed due to fatigue of the pavement surface. As fatigue-cracks develop, they typically interlock in a pattern known as “alligator cracking”. The chunks of pavement between fatigue cracks are worked loose and may eventually be picked out of the surface by continued wheel loads, thus forming a pothole.
The formation of potholes is exacerbated by cold temperatures, as water expands when it freezes and puts more stress on cracked pavement. If a pothole fills with water the growth may be accelerated, as the water ‘washes away’ loose particles of road surface as vehicles pass.
In temperate climates, potholes tend to form most often during spring months when the subgrade is weak due to high moisture content. However, potholes are a frequent occurrence anywhere in the world, including in the tropics (Costa-Rica).
Potholes can grow to feet in width, though they usually only become a few inches deep, at most. If they become large enough, damage to tires and vehicle suspensions can occur.
Alligator Cracking of the Pavement
- Alligator Cracking – is a series of interconnection cracks caused by fatigue failure of asphalt concrete surface under repeated traffic loading.
- Cracking begins at the bottom on the asphalt surface (base) where tensile stress and strain are highest under a wheel load. The cracks propagate to the surface initially as a series of parallel longitudinal cracks.
- After repeated traffic loading, the cracks connect, forming many-sided, sharp-angled pieces that develop a pattern resembling chicken wire or the skin of an alligator. The pieces are less than 2 ft. (.6m) on the longest side.
- Alligator cracking occurs only in areas subjected to repeated traffic loading, such as wheel paths.
- Alligator cracking is considered a major structural distress and is often accompanied by rutting.
- This type of distress often will have two or three levels of severity often within one distressed area. If these portions can be easily distinguished from each other, they should be measured and recorded separately.
Asphalt Repair Options: (Two Options)
Remove & Replace
In the remove and replace option, the damaged areas are marked out with paint, the perimeters are saw-cut and the damaged asphalt is removed to a depth of 2” – 6”. Plant hot-mix asphalt is then re-installed in 1 – 3 lifts and compacted with a vibratory roller. The seam is then sealed with a hot rubberized crack sealer to prevent water infiltration.
This method is used widely for pot holes, alligator cracked areas and other areas of asphalt failure.
Full Depth Remove & Replace- If it is determined that the sub-grade below is unsuitable (i.e.: sand, dirt, clay etc), you have the option of having it excavated and replaced with clean stone of recycled asphalt base to prevent the patch from cracking again and needing further replacement. Full depth replacement can be used to remove 4” – 24” of unsuitable sub base.
Infrared Asphalt Restoration
Infrared asphalt restoration is a very cost -effective method for repairing existing asphalt.
Infrared has gained popularity in the last decade due to its versatility and environmentally friendly alternative to R & R, remove and replace.
Infrared asphalt restoration is NOT designed for every type of asphalt repair, specifically remediating base failure. It is also NOT designed to repair asphalt which has base failure. If utilized for this application, the patch will fail.
Infrared asphalt restoration is ideal for pot-holes, bad oil spots, low spots / high spots, settling around utility structures, remediating trip & falls where the concrete meets the asphalt for in front of retail stores, sunken utility repairs. etc.
Benefits of Infrared Asphalt Restoration
- Recycles Asphalt in place (Can you find a recycling clip art for this?)
- Is considered a “Green Pavement Alternative”
- Creates a truly seamless patch and allows no water to infiltration, because there is no joint
- Can be performed in any temperature
- Scheduling can be performed at night, weekends or any other time independent of the asphalt plants schedule, because it only requires a small amount of supplemental new asphalt.
- The fresh plant mix asphalt can be kept at the proper temperature in our propane fired asphalt hot boxes on our trucks for up to 72 hours
All catch basins / storm drains will either settle or deteriorate over time. This is because as water enters the joints between the steel casting and block or the mortar joints, it causes the water to disintegrate the mortar.
When this happens, especially during the colder months, the water will expand and contract causing the mortar to “pop out”.
In addition, cracks will sometimes appear around the perimeter of the storm drains and allow water to infiltrate the casting.
When any of these deficiencies occur or with a combination of them together, this will deteriorate the integrity of the casting or structure and the following will happen:
- The drain may begin to settle around the perimeter and will further allow standing water to accumulate. If these drains are in a pedestrian trafficked area, in the winter when the standing water freezes, this may become a potential liability.
- The cracks may continue to spread outward and continue to deteriorate the asphalt.
- The casting may settle as the mortar “pops out” and an asphalt lip may appear that will be a tripping hazard.
- A section of the casting or wedge blocks may have fallen out and when the casting is driven over it will move similar to a “see-saw”.
- The top row of block may completely fail and allow the casting to cave in.
Our rehabilitation services can be as simple as patching the asphalt around the perimeter with a quick mortar repair, to an in-depth scope of complete structure rebuild.
Drainage tile, sometimes referred to as French Drains or Under Drains in the industry, is 4” – 6” corrugated flexible drainage pipe which is installed underground in a trench back filled with clean 3/4” drainage stone. The premise behind the design is to wick water from an underground water source and redirect it into a catch basin, drainage area or other suitable area.
Simply, the objective is to prevent water from reaching the surface of your parking lot, sidewalk or other area where ground to surface water caused by hydraulic pressure.
A constant stream of water to the surface from below ground can cause all types of liability issues such as: ice in the winter, moss growth creating an equally slippery surface as ice, clients / customers having to navigate around the wet areas to keep their shoes dry etc.
We have completed many of these exotic projects where property managers felt they would have to deal with water issues for the life of the property, only to have us provide a comprehensive solution and solving their underground water issue in its entirety.
Pulverization and In-place recycling is a cost effective alternative for asphalt parking lots that may have areas of base failure or elevations that are too high to allow another pavement overlay.
In-place recycling is useful for a situation where there is moderate – excellent sub-base material currently in place (i.e.: 6” – 12” of solid stone base) and a thin layer of asphalt (1 ½” – 3”) currently in place.
Asphalt Pulverization—the economical and efficient way to recycle parking lots in place:
Pulverizing is a recycling process that grinds existing asphalt in place in a single pass and blends it with the underlying materials to form a quality base material.
Pulverizing & Recycling has the following advantages:
- Reuse of existing materials eliminates disposal problems.
- Reduction in costs over hauling off asphalt and importing granular fill or ABC.
- Proven to conserve natural resources.
- Faster project completion times.
- Facilitates correction of pavement profile.
- Reduction of heavy trucks on roadways hauling off broken asphalt and hauling in virgin materials.
When deteriorated asphalt pavements are recycled in place, a technique known as full-depth reclamation can be used.
The flexible pavement and a pre-determined portion of the underlying base material are milled and pulverized to a depth ranging from (6 to 12 inches) or more. The pulverized material is mixed within the reclaiming machine while stabilization reagents (such as lime or portland cement and fly ash) and water are introduced and blended with the pulverized recycled paving aggregate. The reclaimer is then followed by grading, spreading, and compaction equipment working in the same manner and sequence as if plant-mixed PSM material were delivered and placed at the project site.