Have you walked your asphalt assets lately? Parking lots, driveways, and roads spend a lot of time in the sun or are being pelted by rain, snow, and salt while silently crushed by tons of trucks, SUVs, and sharply turning vehicle wheels of all types. No wonder their surfaces snap, crackle, and pop over the passing years. There is an inverse relationship between how long their deteriorating condition is ignored and how much it will cost to repair.
As a responsible condominium or HOA leader, you or the community’s grounds committee should be walking the bituminous asphalt surfaces on a regular basis while maintaining a log of their current conditions for periodic reporting to the Board. As paving can be the costliest asset of the community especially if it is an HOA, a wise board has a relationship with a local knowledgeable paving contractor or their reserve study engineer to provide technical assistance. Even better, the community and contractor should have a standing contract with a pre-agreed schedule of various paving repair unit prices for both emergency and routine maintenance.
To avoid premature failure of asphalt paving and the associated higher maintenance costs, I have always recommended my community clients follow a ten-point maintenance plan but before you read this list let us review the basics. Asphalt pavement is bituminous concrete and called ‘concrete’ because like cement-based concrete, bituminous concrete has a mineral aggregate of stone and sand. This aggregate is held together with a binder of petroleum derivative asphalt. Beneath typical paving there is a sub-base of 4 to 8 inches of a well drained, compacted soil and gravel mix. The first layer of paving called the binder course is 1 ½ to 2 inches thick and covered by a topping coat of 1 ½ inches. If it were not for the sun and water, asphalt paving would last a long time, but paving begins to deteriorate as soon as water begins to penetrate the binder course while UV rays remove asphalt from the topping coat. This can happen in less than five years. This is why adding a sealing coat in the first 2 to 5 years is recommended.
Paving Maintenance 10-point Plan
- Monthly sweeping and cleaning. Remove dirt, debris, and trash to prevent damaging the asphalt and environment while maintaining good traction for vehicles to reduce accidents.
- Eliminate standing water. Identify low spots where water accumulates as standing water will erode the pavement base causing it to crack and crumble. Fill low spots with patching compound to minimize hydroplaning and slipping hazards.
- Fill cracks and repair crumpling pavement. When water begins to infiltrate the pavement here in Maine the freeze / thaw cycle takes its toll. The small cracks become larger in the binder course and eventually the sub-base begins to fail. At this point surface cracks, settlement, alligatoring, and other surface visible signs including potholes make an appearance. Your Preventive Maintenance Plan should include the filling of these cracks with standard joint filler to within 1/8 to ¼ inch of the top of the crack. Potholes and other localized damage can be cut out and filled with patching material as needed.
- Ensure proper water drainage. This will minimize water accumulation; preserve the integrity of the asphalt paving; and reduce potholes and ice patches. Catch basins should be inspected annually and cleaned of debris.
- Asphalt sealing. Sealing materials do not add back the asphalt lost due to UV deterioration. It only protects the pavement for a brief time from further deterioration such as shrinkage cracks and raveling (loss of surface aggregate). It does not bridge large cracks or fill roadway depressions. Therefore, if the pavement is over five years old and has never been seal coated, it has lost its chance for physical benefit to the life of the pavement. At that point it is only a cosmetic remedy.
- Consider overlay. The deteriorated paving conditions sometimes allow the postponement of a major project with all its attending traffic and extended project schedules with the use of an Overlay repair. This method uses an overlayment of asphalt material on top of the existing surface extending the life of the pavement and postponing complete reconstruction. Overlays are applied with or without a geotextile fabric layer.
- Consider pavement reconstruction. If an overlay solution is not suitable then a pavement reconstruction repair method is needed such as Milling and Asphalt Replacement (MAR) or Full-Depth Repair (FDR). Milling and Asphalt Replacement projects use a milling machine on the top surface to a depth of 1 to 2 inches. The removed material is hauled to a recycling facility and is replaced with a new asphalt mix often containing recycled asphalt pavement (RAP). This method can add 10 to 15 years of life to the current roadway.
- Consider Full-Depth repair. If the sub-base has failed, a Full-Depth Repair may be the only option. This may require removal of large areas of deterioration and repairing the sub-base followed by a 1 ½ inch binder with a 1 ½ inch top layer. If the roadway or parking area deterioration is widespread, the options include a reclamation project where the top 6 to 12 inches of pavement and sub-base is grounded into a recycled material used for a compacted and graded foundation for a new paving surface with a life expectancy of 20 to 25 years.
- Renewed striping. Stripping of roadways and parking lots is susceptible to wear and tare and should be reviewed every two years to ensure efficient traffic guidance, reduce risk of accidents, and ensure compliance with latest ADA and safety regulations.
- Review of lighting, security cameras, and landscaping. This includes improvement of bollards, car stops, and light pole bases.
Well maintained asphalt pavement surfaces are not just about safety and reducing future cost but it is also at the heart of the Board’s fiduciary responsibility of providing a level of quality of life in accordance with the community’s expectations.
Written by Jack Carr, P.E., R.S., LEED-AP, Senior Consultant Criterium Engineers
Published in Condo Media