 If it weren't for water and freeze-thaw cycles, our roadways would probably last twice as long. But although we can't control the weather, we can prevent a lot of the damage it can cause. This program covers the procedures to follow for crack-sealing bituminous pavement. Cracking is one of the first results of water under the pavement and temperature changes. The Department has approved two methods for sealing cracks. In one method, the cracks are cleaned with a high-pressure air blast. The other method involves cleaning with cracks with a heat lance. Other than the cleaning method, both procedures are the same. So let's take a look at each step of crack-sealing beginning with traffic control. Although the traffic control and the types of roads you'll see will vary considerably from one job to the next. All crack-sealing jobs have two things in common. You have to close one traffic lane. And second, because of the speed of this operation, the closure can be of considerable length. So before you leave the station, make sure you have enough cones on hand to close the length you need. Otherwise, you'll spend most of your time taking down and setting up the devices. And of course, discuss all the requirements with your supervisor. Make sure you have all the flaggers and signs necessary to do the job safely. When the traffic control is in place, the operation can begin. As you can see, the first step is cleaning the cracks. And in this case, they're being cleaned with the air blast method. The first thing you should notice are the goggles. This is one operation where eye protection is an absolute necessity. Flying debris can cause serious injury if you don't take all the necessary precautions. Now cleaning the cracks is a lot more involved than it looks. To begin with, you need enough air pressure to remove the loose material. But be careful not to use too much because you'll damage the pavement. This is especially true when you're working with old pavement. And just about the only things you can do to prevent damage are to reduce the air pressure and move the wand quickly along the crack. As you clean the crack, keep the wand down close and always work from the center of the road toward the outside shoulder. The whole reason for working in this direction is to keep flying debris away from passing vehicles. When you've finished cleaning a crack, there is almost always debris left on the pavement. But resist the temptation to blow it off the road with a wand. Remember, you just cleaned the crack. Don't force dirt back in. And besides, the small amount of debris will get blown off the road by the traffic anyway. So for cleaning cracks, always wear eye protection. Use enough air pressure to get the dirt and debris out. But be careful not to damage the pavement. Always work from the center of the road toward the shoulder. And keep the wand close to the crack so the crack is thoroughly cleaned out. Okay, that's the air blasting method. Now let's look at the heat lamps method. Notice the eye protection. Remember, the heat lamps uses a lot of air pressure too. In addition, heat lamps are incredibly loud, so ear protection is also required. Aside from cleaning the cracks, the purpose of the heat lamps is to slightly melt the road surface. That way the sealant will bond better to the pavement. Of course, you don't want to heat the pavement too much. So as soon as you notice any discoloration in the pavement, move the lamps along. And if you notice any more than the slightest amount of smoking, you're not moving the lamps quickly enough. And those are the cleaning methods. From here on, the procedure is the same. But before we look at sealing the cracks, you should know that one of the main reasons that the sealing material fails is because it's applied at too low a temperature. So always read the manufacturer's recommendations and make sure the sealant is heated to the proper temperature before you begin using it. Okay, now sealing. As you can see, this step moves along rather quickly. It has to. If you don't move the wand along quickly, you'll end up with sealant all over the place. So try to gauge your speed so that the material just slightly overfills the crack. And notice that the squeegee follows as close as possible behind the wand. That's the way to do it. If the sealant cools off, you won't be able to move it where you want it. This diagram shows what I mean. By slightly overfilling the crack and immediately following with the squeegee, the sealant will function like a bandaid over the crack. The sealant on the pavement surface helps hold the sealant in the crack in place. So again, the squeegee should follow the wand as closely as possible to make the sealant act as a bandaid. And that's the sealing procedure. But what crack should be sealed? Well, that's a question you'll have to take up with your supervisor on each job. For the most part, all large, isolated cracks should be sealed. And small alligator cracking should be left unsealed. But the real factory is money. So in some cases, you'll have to seal small cracks like these because there's no money for other repair procedures. And that brings us to the end of this program on crack sealing. Try to keep the points you've seen here in mind and you'll end up with an operation that is both productive and, most importantly, safe.