Many of you are gearing up to repave some of your roadways this summer. Gone are the days when the likely paving contractor lived in the area and coached the local little league team. Maybe you relied on that team knowing you, knowing what you were expecting, and having a vested interest in your satisfaction with the job. It’s just as likely these days that you may receive bids from even an out of state company, one that isn’t focused on your particular needs, or one that isn’t looking at a long-term relationship.
Contrary to our sometimes cynical expectations, most contractors are professional and will conform to the standards of care their industry demands. But, your charge is to be a good consumer and these days, that requires a heightened level of attention as you put out requests for bids. Good contractors will appreciate the clarity of a detailed request because it means a greater likelihood that everyone is bidding on a level playing field. A simple e-newsletter article can’t cover all the things you should detail, but let’s go through some of the things you should be specific about, particularly thinking about those municipal street examples that are likely your jurisdiction.
Limits of work. It can be tempting to simply list the streets you want paved, but you need to be clear if the work ends at the curb radius to the intersection or if it includes the intersection with other streets (presumably extending to the ending radius entering each of those streets). A simple aerial view from one of the internet browsers marked up with the limits can be very instructive. Does the work include just the travel lanes or also the parking lanes. Assume they understand and you will get what you get…which is to say a guaranteed argument during the work that was completely unnecessary.
Scope of work. If you say you want them to pave 2”, that’s what you can expect. Oh, you wanted them to mill 2” first? The contractor you are worried about may see that as a place to play a game. Be specific. Do you want them to mill the surface and if so how much? Don’t assume they will mill 2” just because you said to pave 2”. Be specific on both fronts. Do you want them to reprofile the cross slope? If so, be specific about the end product (e.g., 2% cross slope from centerline).
If they are milling, where do the millings go? Do you want them and if so, where do you want them placed? Again, an aerial map of your site showing the area they will have available will avoid them spreading the millings all over the place. You can do a little simple math to figure out how much space is needed and that is a good idea, to avoid unnecessary arguments later on. If the contractor is expected to take possession of the millings, say so.
Be clear about tack, because, for some reason, asphalt is famous for premature failure due to poor tack, even though the stuff is dirt cheap. You can get as detailed as you like on tack, but at a minimum, tell them you expect a uniform application of 0.05 to 0.15 gallons per square yard and you want all vertical surfaces (curb gutters, manholes, water valves, etc.) tacked as well. And then, if they do that sporadic, string tack nonsense that some still try to get away with, grow a spine and tell them to back that distribution truck up and try it again before they pave. If you are not clear up front, it will be harder to get the quality job you are after later. They are going to cry about tack getting on their tires and if you did a good job in your request for bids, you get to say that’s not your concern; they should have done it right the first time. Now back it up.
Surface preparation should go without saying, but it doesn’t. Be clear that the surface is to be swept or vacuumed prior to placement of tack and asphalt.
If you have some questionable areas, make sure you include some provision for them to repair the subbase materials. You can mark out with paint areas that you know you want repaired and/or you can ask for a separate unit price for repairs that become evident after they mill and “proof roll” the pavement. If it’s pumping, you need to address it or you are putting expensive material on subbase that can’t support it. Unit prices can be per square foot, per square yard, per square foot-inch (i.e., a square foot one inch deep), etc., the latter being the most useful. That way, if they have to excavate out three square feet, eight inches deep, they charge you for 24 SF-in (3×8; you get it). Oh, and you decide what does and doesn’t get cut out (see below about not being an absent owner).
What material do you want? Again, be specific or get what you get. At a minimum, you need to specify the nominal aggregate size and the binder you are after. For low volume, low speed streets, you will commonly want 9.5 mm or 12.5 mm stone. For a finer surface layer, 9.5 mm is a good choice, but your minimum (compacted) lift thickness should be 1¼” and your maximum should be 2”. For 12.5 mm (also a good choice; just a little rougher, but also a good bit tougher for those trash trucks, oil trucks, and so on), your lifts should be between 1½” and 2½”. Outside of these ranges, the compaction equipment either can’t achieve adequate density or will crush the aggregate. Stay in those ranges.
The binder is what you might think of as the oil; we won’t quibble over the terminology here. These days, all the plants use performance grade (PG) binders and with rare exception, PG 64-22 is suitable for municipal streets. And just to decode a bit, 64 is 64°C (147°F) and -22 is -22°C (-8°F), the upper and lower average seven-day pavement design temperatures. In short, the binder is engineered to resist rutting and shoving during those lazy, hazy, crazy days of summer and resist cracking when Father Winter is in town. Your other common choices in Delaware are PG 70-22 and PG 76-22, but these are more expensive, much tougher to work with around interruptions like manholes, and are more suitable where you have lots of heavy trucks on a regular basis.
Insurance and business license. You can wait to receive the insurance certificate from the chosen bidder (and you want that before you issue Notice to Proceed), but it’s good practice to see their business license as part of the bid.
Schedule and weather conditions. If your job is small (and in a state where DelDOT’s jobs dominate, yours probably is) the contractors and the asphalt batch plants are going to fit you in around the larger ones. That’s fine, but you need to be clear about when your job is to happen. No sooner than when and no later than when? Do they have to avoid certain times (a few days before and after a holiday, a parade day, a block party, etc.)? Make it clear that the job cannot proceed with wet pavement or under the threat of rain, the base cannot be frozen, and ambient air temperatures must be 40°F and rising. Stick to your guns on this, because small jobs have a funny way of getting pushed into the fall and then the early part of the winter and suddenly, it’s 38 degrees, overcast, and getting cooler and your contractor is saying, “we may not get a better shot.” At that point, you’re better advised to wait for spring and the contractor can whine all they want, but they should have scheduled better. But, you only get to stick to your guns if you’ve been clear in your expectations. See how the theme writes itself?
Contractor and owner responsibilities. Who takes care of notifying residents that driveways will be inaccessible and who do they call if they have questions or concerns? What advance notice do you want for yourselves and residents before game day? Who takes care of parked cars from residents that don’t abide by the notice? Are you taking care of temporary traffic controls (signage, detours, barricades, pedestrian accessibility, etc.) or are they (either way, this needs to happen)?
Lump sum or unit cost? There’s no right answer. Lump sum contracts are helpful, but the contractor may include a contingency of 10-20% to cover the risk that more material will be necessary and you pay that if it’s needed or not. You can pay by the square yard or square foot and then you have to agree on the measurement in the field; if you go this route, make sure to periodically inspect the compacted thickness because your less than best contractor may get a little light. You can pay by the ton of asphalt (if so, you absolutely want to see the truck tickets as they come in and you want to be present to ensure that all of the asphalt you paid for got used on your job); if you chose this route, make sure to check the thickness periodically because an ornery contractor may make it a bit fat to boost the quantities. Regardless, make sure that everything is incidental to the price(s) – milling, surface preparation, temporary traffic control, tack, materials, equipment, manpower, and cleanup. If they are doing the pavement markings, make sure that is clear also.
Pre-construction meeting. Plan on one. Require that the foreman, superintendent, or supervisor that will actually oversee the job is present. Others are welcome also. Go over all the particulars of the job, ask questions about the contractor’s approach and schedule, and ask if there is anything they are unsure of.
This is where you ask the contractor to walk you through the plan. How many trucks will they be using, what plant is the mix coming from, what are the contingencies to ensure that the project goes smoothly? You want to be reasonably satisfied that once the paver starts, it never has to stop (it will, but we are entitled to our fantasies). A good contractor with a good plan can minimize those interruptions. And it matters. Every time that paver stops for an extended period of time waiting on a truck, that hot mat gets cooler and cooler before that breakdown roller hits it. That’s where you can expect premature pavement distresses and that telltale little bump in the ride that you will come to notice once you become an asphalt nerd. There’s no such thing as a perfect paving job, but you can get a more durable pavement from a contractor with a good plan.
You also want to know what rollers they plan to use. Those little 5-ton “driveway” rollers have their place in finishing out the surface, but unless you are paving a driveway, you also want to see at least one sizable (say 12-ton) vibratory breakdown roller to achieve optimal compaction and ensure a durable pavement.
Make it clear that you don’t want to see the trucks “bump” the paver (i.e., when backing in place; the truck should instead stop short of the paver and the paver moves up to “pick-up” the paver); once you become a cynical asphalt nerd, you’ll find yourself judging pavement jobs where this occurred in a little game we call “counting the trucks.” Don’t be a hater; just make sure your jobs don’t have them.
Designate an area, off the road somewhere, for them to clean out their truck tailgates. Make it clear that you don’t want to see them scraping dry, cold mix off onto the tack in front of the paver to create premature pavement failure.
Tell them you want to see well laid out passes with straight lines (it’s not about
prettiness), and you want your longitudinal joints to be properly laid. This last part is an artform all to itself and an experience roller operator can work miracles, but a poorly laid longitudinal joint will open prematurely, allow water to infiltrate, and prematurely distress your pavement.
If you have a resident with peculiar or unusual concerns (the azalea bush in the front yard that can’t be bruised), tell the contractor and save both of you some future headache. This is often your last chance to avoid unforced errors.
Utility coordination. Presumably, you have some sort of utility policy and/or a street opening process. If not, get one on the books. You need to accommodate utilities in the right-of-way, but you don’t have to put up with them cutting open your brand-new pavement. Communication is the key here and you should be well out ahead of your pavement jobs to tell all owners of underground utilities that if they want to open the street, now is the time, because after you pave, you are going to be a hawk about how they restore the trench and the pavement.
The same goes with your own utilities, particularly storm drainage issues. If there are stormwater catch basins that need attention, take care of those now so your paving job can continue to look pretty for years to come. When you cut open your pavement a year after the paving job or allow others to do it, residents just shake their heads…and here, they often have the upper ground.
Next, make sure you inspect while the work is being done. Get yourself a retroreflective vest and some boots to make yourself more welcome up close to the action. Be ever-vigilant around moving equipment and keep yourself out of harm’s way. Be present, take photographs before and after, take notes, ask questions if things don’t look right. Ask for the truck tickets or at least a copy of them after the job. You don’t have to be an expert, but if you are an absent owner, you’re letting the fox run the hen house. Most foxes are reasonable enough animals, but the best of them are more mindful when someone is watching.
And finally, when it comes time to replace the pavement markings (stop bars, yield lines, crosswalks, etc.), don’t just put them back where they were. Consult the Delaware Manual on Uniform Traffic Control Devices (MUTCD, see Part 3) to ensure that you are putting them in the right place, they are the right dimensions, and so forth. Things have probably changed since you last paved.
If you missed our most recent offering of the Asphalt Best Construction Practices training workshop, you can browse the slides on our website and get some of the gist. Look for this training again in the fall, as we typically offer it (free to local agency personnel) twice a year.
The Delaware T2/LTAP Center’s Municipal Engineering Circuit Rider is intended to provide technical assistance and training to local agencies and so if you have pavement management questions or other transportation issues, contact Matt Carter at matheu@udel.edu or (302) 831-7236.
You must be logged in to post a comment.