Asphalt Maintenance, Repair & Replacement

Everyone has heard the saying; " There are two seasons in Michigan, winter and road construction".   We are right in between the two at the moment.

Nevertheless, the best time for actually performing asphalt repairs is spring and summer. However, just like most other association projects, the time for planning is here.

THE TITLE OF THIS SESSION IS ASPHALT PAVING SEALING AND REPAIRING & REPLACING.  A VERY BROAD TOPIC AND ONE THAT HAS A LOT OF INFORMATION.  WE’VE PRIMARILY TAILORED THIS FOR CONDOMINIUM ASSOCIATIONS AND MANAGERS. 

The first step is to assess your pavement condition.  In order to assess the pavement condition for repair or reconstruction in the summer, you will need to visually inspect the asphalt in early spring, just after the frost comes out of the ground.

Items to take note of are cracks, “alligatored asphalt”, and areas around catch basins that are deteriorating and of course pot holes. (Hopefully, repairs are done prior to getting potholes)

If your inspection leaves you unsure of what to do, you may need to retain the services of an engineer or meet with a reputable contractor to review possible course of action. Either of which can assist you in drafting the specifications for reconstruction or repair. MAJOR PROJECTS SHOULD HAVE AN ENGINEER INVOLVED EARLY ON TO DETERMINE WHAT SHOULD BE DONE.  CORE SAMPLES AND ANALYSIS OTHER THAN VISUAL INSPECTION MAY BE NEEDED TO DETERMINE HOW BEST TO PROCEED.   WHILE AN ENGINEER CAN BE EXPENSIVE, THEY ARE TYPICALLY ONLY 3-5 % OF THE TOTAL COSTS OF A MAJOR RECONSTRUCTION PROJECT. HIRING AN ENGINEER PROVIDES A MEASURE OF PROTECTION FOR BOARD MEMBERS AND PROPERTY MANAGERS FROM MAKING AN UNWISE DECISION ON WHAT CAN BE A VERY COSTLY PROJECT.

If you are fairly certain of what you need, another idea is to have a pre-bid conference with several reputable contractors. Show them the problems, seek their input and create specifications that meet your needs with their input.

Either way, it is a good idea to have these specifications in written form prior to bidding. The written specifications should include start date, completion date, phasing information and other special work rules of your community or association. 

If the written specifications are not clear-cut and in writing, you may receive wildly different bids. (You may already know of the problems of trying to compare quotes that are not for the same scope of work!!!)

If you are fortunate enough to have good pavement conditions, remember that preventative maintenance can lengthen the effective life of your pavement. (all pavement in Michigan has an effective life, typically shorter than expected). Preventative measures include crack sealing where applicable sealcoating.

Whatever type of repairs you may need, get your work scheduled for late spring or summer. All asphalt products, paving material, rubber joint sealant, sealcoat, are best applied in warm dry weather. The effects of cold weather on most asphalt paving product applications are not beneficial.  Cold weather asphalt paving is risky and not always as aesthetically pleasing and should be avoided unless necessary.

Before we get to the various repair / replacement options, lets talk for a minute about what causes pavement to fail.

An asphalt roadway or parking lot is actually part of a system.  The system must take into effect: use (Heavy or light), ground (subgrade) conditions, drainage (either inverted crown, (center drainage), or standard crown (drainage to the curb), placement of edge drain and catch basins. Once these factors are accounted for, a cross section for the aggregate and asphalt can be determined.  A typical cross section includes a specified depth of aggregate base and a depth of pavement. In some instances, deep strength pavement (no aggregate and 7.5” to 10” of asphalt) can be called for on top of the subgrade, most often aggregate base is used prior to placing asphalt. One typical cross sections is 8” of 21 AA stone and 4” of pavement.  There are many different cross sections. 

What causes asphalt to Fail:

1.       Heavier than anticipated loads on the pavement cross-section. (garbage trucks, through traffic)

2.       POOR SUBGRADE CONDITIONS, Organic material, topsoil, wood, wet Clay, No drainage.

3.       Excessive Water in subgrade (sprinkling excessively, signs that water is coming out of the ground / asphalt

4.       Freeze Thaw Cycle (coupled with water or poor subgrade conditions)

5.       Overall wear and age (aging process of asphalt- flexible when new, brittle when old -  Black to gray coloring)

Typical Asphalt Maintenance / Reconstruction Terms

1.       Cold Patch- Asphalt material that can be used to fill potholes, not a long-term repair. Very flexible, does not have the strength or durability of Hot Mix Asphalt. Cold patch is temporary.

2.       Hot Rubber Joint Sealing- Also Crack filling- Process of filling cracks in asphalt or concrete with flexible rubber material.

3.       Sealcoating- Process of covering asphalt with a very thin layer of liquid asphalt or liquid coal tar pitch emulsion.

4.       Skin patching - Placing a thin layer 1” to 1.5" of asphalt over the surface of a problem area. (reflective cracks will occur)

5.       R & R- Removal and replacement of deteriorated asphalt.

6.       Catch Basin- A surface water collector.

7.       Overlay- Place a pre-determined thickness of asphalt over existing asphalt also called "capping". Typically, a minimum of 1.5" in depth due to aggregate size. (reflective cracks will occur)

8.       Butt Joint- When asphalt needs to be removed at a fixed point such as a garage door, or the transition to other fixed points such as, existing asphalt, sidewalks, existing concrete curb, etc to provide a smooth transition, and more importantly proper drainage.

9.       Pulverization -Process whereby the entire thickness of existing asphalt is crushed into very small pieces, graded and compacted and used for additional base for new asphalt.

10.   Milling -Stripping and removal of a predetermined depth of existing asphalt and removal from the location.

11.   Aggregate Road Base- Typically limestone, crushed concrete or road gravel. Standard Michigan designations: MDOT 21AA, (comes in either crushed concrete or Limestone) and 22A road gravel.

12.   Undercut - Process of removing bad or unstable aggregate base and or sub base and replacing it with stable aggregate base. Frequently, larger aggregate known as 1” x 3" or 2" x 4" is used to fill and undercut. These large aggregates are then “choked off” with 21 AA a much smaller material.

13.   Edge Drain- Perforated drain tile that is used to take sub surface water away from the road base. Important in areas of heavy irrigation use and or wet clay soils.

14.   Tack Coat - The "glue" that helps bond two layers of asphalt pavement together. A proper application of tack coat is necessary when placing an overlay on existing asphalt or, multi course construction of new asphalt pavement.

15.   Geo Grid or Grade stabilization fabric- material used stop wet or unstable soils from contaminating, (pushing up through) the aggregate base.

16.   Various grades / types of asphalt- Base Course: 500C, 700 C & 11A, Leveling, Commercial grade, 1100L, 1300L, Wearing Course: Commercial grade, 1100T, 36 a, 1300 T. Many other possible grades. All asphalt is made up of only three items: Asphaltic Cement, aggregates (various sizes) and air voids.

17.   Compaction.  Key to a successful asphalt pavement system.  In order to achieve compaction, not only must you have the right equipment i.e. rollers of the correct size, but the subgrade, and aggregate base must be intact and hard.  Soft subgrade will translate up to the surface and cause failures.  In areas where a roller can not compact the asphalt, a hand tamper must be used. Typically areas that must either be placed by hand and or compacted by hand be “rougher” looking than areas that are machine placed and compacted.

18.   Grade- Minimum of 1% slope to achieve positive drainage.

19.    Asphalt Curb- Placed from a curbing machine typically 7” tall by 5-6” wide.  This does NOT stand up well to snow plows and can be damaged easily by cars. Where possible, asphalt curb should be backfilled with topsoil to add stability and be less likely to be moved or damaged.

20.   Concrete Curb and Gutter- Various thickness and sizes, much more resistant to snow plows and other vehicles, much more expensive than asphalt curb.  Concrete curb must be backfilled.