 Here in part two of chip seal application, we'll look at checking application rates, applying binder, spreading chips, rolling, joint construction, brooming, and opening to traffic. So let's start with checking application rates. Both the oil and chip application rates should be verified. As a general guideline, you'll need between one and a half and two liters of oil per square meter of surface and between nine and fourteen kilograms of chips per square meter. To check the chip application rate, place a tarp on the surface ahead of the chip spreader, let the spreader go over it, and then weigh the chips. On the tarp, the crew then places a frame to collect the chips. The frame has an inside dimension of one square meter. The spreader begins applying chips and passes over the tarp and frame. Next, the crew removes all the excess aggregate outside the frame and the frame itself, leaving the collected chips on the tarp. They then fold up the tarp and weigh the chips to find the application rate. In this case, the chips weigh ten kilograms, so the application rate is ten kilograms per square meter. The oil application rate can be checked in the same basic way. Using a pan or a piece of non-woven geotextile material, one square meter in size, to catch and retain the oil sprayed by the distributor, and then weighing the collected oil to calculate the rate in liters per square meter. In both cases, compare the results with the target application rates and make adjustments to the equipment as necessary. When the rates check out, you can begin chip sealing. The first step, of course, is the binder application. The binder shots must start and stop with neat straight edges, so get the distributor in position. Then place building paper across the lane just before the start point and also just after the end point. The distributor then moves forward at the correct application speed. The operator starts spraying on the building paper so that the application from the start point on is uniform. Be sure to end each shot on paper, too. Look closely over the binder application. It must be uniformed to end up with a good chip seal. If you see anything wrong, stop the distributor immediately and correct the problem, whether it's clogged nozzles, improper pump pressure, faulty nozzle adjustment, or incorrect spray bar height. Next comes the chip application. The chip spreader should also begin and end its applications on building paper to provide a neat, clean edge to the chip seal. For starters, there should be enough trucks to supply the chip spreader steadily to avoid halting the operation. The aggregate haul distance and the productivity rate of the chip spreader are factors in determining how many trucks are needed. To control the chip application rate, the spreader operator should refer to the unit's tachometer. Also, it's a good idea to mark off the length that each truck load should cover. Whenever further verification of the application rate is desired, use the procedure shown earlier using a tarp and frame. If an emulsion is being used, be sure the spreader follows as close as possible behind the distributor, never more than 30 meters. Here's why. When placed quickly, the chips can be embedded in the oil. Then, when the oil hardens, the chips will be held firmly in place. But if the spreader lags behind and the oil breaks, a film will form. Then, when the chips are spread, they won't embed or adhere properly. The same procedure should be followed when asphalt cements or cutbacks are used, because it's almost always best to run a tight operation. That way, there's less chance of traffic driving on the oil. With rare exceptions, the chip spreader should stay within 30 meters of the distributor. Regardless of the type of oil being used, the speed of the operation is important. If it moves too fast, the chips will roll when they hit the surface. The problem then is that the chips exposed side is sticky, so they'll be picked up by the rollers and by traffic. So look over the application. There shouldn't be any oil on the top of the chips. Then it's time to look at the rolling. Rollers follow closely behind the spreader to make sure that all chips are firmly seated in the oil and that the chips are lying flat, not one on top of another. To do that, the roller operator should establish rolling patterns by offsetting the tires and by rolling the entire surface at least twice. The rollers have to be operated slowly enough to avoid throwing the chips, eight to nine kilometers per hour as the recommended maximum speed. And all stops and turns should be made gradually to avoid damaging the fresh surface. Proper truck operation can help considerably in rolling the new chip seal. Like the rollers, they can stagger their paths across the road, offsetting their wheels so that each truck rolls a different part of the surface. Beyond that, trucks have to be careful not to damage the chip seal, so the slower the speed, the better. And each turn and stop should be as gradual as possible. Remember, any sudden movement on a new chip seal will dislodge the chips. In addition, all operators should avoid driving over any exposed oil. And that brings us to joint construction. There are two types, longitudinal, which run along the length of the road, and transverse, which run across the road. First, longitudinal joints. When the adjoining lane will be chip sealed, there should be a narrow strip of oil that the spreader doesn't cover. Some refer to this narrow strip as the meat line. Whatever it's called, it should be left uncovered because there's not enough oil there to hold the chips in place. This is because there's no overlap at the end of the distributor spray bar. The chip spreader operator has to be careful, though, to make the meat line only as wide as the spray from the last nozzle, about 20 centimeters. On the next pass, the distributor has to line up so the last nozzle sprays the meat line. This double spraying of the meat line gives the surface the necessary coverage and ties the two applications together. Be sure, however, that the meat line is never made in wheel paths. Meat lines can be constructed only at the center line of the road, the center line of the driving lane, or at the edge of a driving lane. And, no meat line should be left open overnight because exposed oil is very slippery. This means that the ends of adjacent application should be together when work stops for the day. As for transverse joints, every application that takes off from a previous one has to begin on building paper. The reason is simple but important. You have to avoid spraying oil on the chips already in place. If you don't start the application on building paper, you'll be placing one application over another and building a bump in the surface. As stated earlier, use building paper at the end of each application, too. That's the best way to keep the edges neat and even. Be sure to dispose of this paper properly, according to the regulations and force. Now let's look at brooming. While some amount of loose chips is unavoidable, they need to be removed by light brooming to prevent broken windshields and also to keep them from dislodging the bonded chips. But be sure the brooming itself doesn't dislodge the aggregate. If it does, suspend it until a good bond has formed between the binder and chips. Also, make sure the broom is not applying excessive pressure to the surface. In rural areas, the loose aggregate may be broomed to the shoulders of the road. In urban areas, however, they should be broomed to the curb or center line and then removed manually or by vacuum device. And that brings us to the final step of the operation, opening the chip seal to traffic. Opening fresh chip seals to traffic is desirable. The traffic will help to roll the surface further. Still, there are a couple of things to keep in mind. First, you want the traffic to travel slowly, no more than 40 kilometers per hour. And second, you don't want sudden accelerations or slowdowns. They would likely dislodge the aggregate. Pilot cars and flaggers are recommended to direct and control the traffic flow. In the absence of a pilot car, reduced speed limit signs should be posted. And that brings us to the end of this second part of the video program. As you've seen, each and every step is crucial to the success of the application. Your thorough attention to the details will result in a good chip seal every time. In part three, you'll see typical problems that occur in chip seal operations.