 There are nearly 3,000 structures in Utah, and we in the DOT are responsible for half of them. And no two are exactly the same, ranging from an impressive crisscrossing of concrete overpasses to a simple bridge over troubled water. But all of these structures are alike in one respect. They share a common enemy, water, and its ally, dirt. Dirt traps moisture, which in turn rusts steel and deteriorates concrete, all of which, if left untreated, can lead to disaster. So it's our job to keep something like this from happening. We can't control the weather, so there's no way to keep the structure from getting wet. But we do have a say in where the water ends up. And that's what this course is all about. Keeping the structure clean and the drainage system open so that water won't penetrate the structure and eat away concrete and steel. We'll start by looking at cleaning underneath the structure and then we'll look at various methods of cleaning the deck. Finally, we'll look at clearing out the drainage system. So let's get started with cleaning underneath the structure. Mention the word structure, and even the most seasoned engineer will cringe. There's a mind-boggling number of different bridges, each with an equally confusing array of parts. Luckily for all of us, this is routine structure cleaning, not an advanced civil engineering course. It's more important that you clean the structure and its parts than it is that you know the technical name for each structure and its components. But all bridges have common components you need to be aware of. If your supervisor tells you to clean the bent cap, it would help to know where and what a bent cap was. This chart shows the basic components of all bridges. This is the bent cap. It rests on the columns, which in turn are supported by the footings, which rest on the piles. This entire section, the piles, footings, columns and cap, is referred to as the bent. As you can see, that's a lot of concrete. And like I said earlier, dirt will trap moisture, which deteriorates concrete and weakens the structure. So if it's dirty, the entire bent should be cleaned, particularly the cap, because it's flat and dirt and water tend to build up there. It's equally as important that the abutment, back wall, berm and pedestals are cleaned. These two provide support and something as simple as dirt buildup could eventually topple the sturdiest structure. As you can see here, the entire area along the berm and the pedestals needs to be cleaned. The slope protection also needs to be cleaned. Dirt and moisture will cause cracking in the concrete. These cracks will allow water to penetrate and eventually erode away the slope. So as you can see, cleaning can save a lot of time, money and maybe even lives. There are many types of bearings used to support the girders and allow the bridge to expand and contract. These two need to be cleaned because moisture trapped by dirt will rust steel and deteriorate in cracked concrete. Okay, we've covered some of the basic parts underneath the structure and why you need to clean them. Now let's look at the cleaning procedure itself. As with any other maintenance activity, the first thing to do is set up all the necessary traffic control devices and signs. There is another course that covers traffic control procedures, so we won't go into a lot of detail here. Always set up the roadwork ahead sign first to give motorists adequate warning. Then because one lane will be closed to traffic, set up the lane drop symbol sign. Place the cones and move the arrow board into position. If you have any questions at all about proper setup, ask your supervisor. Traffic control is no place for guesswork. With the traffic control properly set up, motorists should be safely maneuvering around the work site, which means you're ready to begin cleaning. In order to clean most of the parts under the structure, you need to be able to reach them. In this case, a reach-all bucket truck is being used. You can clean most structures with just about any type of bucket truck. If you need a special piece of equipment like the reach-all, contact the structures division. But whatever piece of equipment you use, make sure you follow proper and safe operating procedures. Here the bucket is being positioned to clean the bent cap and bearings. As you can see, not only are the bent caps dirty, but they're plotted with large potentially dangerous chunks of concrete. I'm not sure how they got there, but one thing's for certain, they need to come down, but not on their own due and unexpected time. They must be removed now. So when the area below is clear, water blast or push the concrete off the bent cap, then clean the entire cap. Always wear the proper safety gear. You need a hard hat, rain gear, and goggles to protect you from flying water and debris. While cleaning, never lean too far out of the bucket. If you can't reach an area, move the bucket, not your body. It may take more time, but it's the only safe way to do it. Clean the cap, girders, and bearings. If needed, adjust the spray nozzle to get enough pressure to clean the bearings. It's important that you get everything as clean as you possibly can. Here's a finished section. It looks good. All of the dirt has been removed, effectively prolonging the life of the structure. Continue to clean underneath the entire structure until all the dirt is removed, and that's underneath. Now let's look at the top of the structure, more specifically at the deck and parapets. A dirty deck like this leads to serious problems. Water gets trapped in dirt and begins deteriorating the deck, causing potholes and eventually enough damage that the entire deck will need to be replaced. The best way to fix these problems is to prevent them from occurring in the first place. And one of the best ways to do that is by simply cleaning the deck. Here again, the first step is to set up all the necessary traffic control devices and signs. Set the inductor's nozzle so you can clean the entire deck. With the traffic control in place and the nozzle set, turn on the water and slowly drive the inductor forward. The spray should fan out in both directions, pushing the dirt forward and toward the parapet walls. Continue forward until all the dirt is washed from the middle of the deck to the sides. Next, readjust the spray nozzles for only one side. Then turn on the water and slowly proceed along each parapet wall. This helps loosen the hardened, caked material along the parapet and further pushes material toward the wall. With the material loosened and against the wall, use the inductor to vacuum up all the dirt and debris. Set the collector ahead of a section of dirt. Use a hand sprayer to wash the dirt toward the collector where it gets sucked up by the inductor. Make sure you wash as much material as you can toward the collector. Try to keep from washing the dirt back into the middle of the deck. Stand behind the dirt and walk forward, pushing it into the collector. Keep moving the collector forward and washing dirt into it until the entire deck is cleaned. When you've finished the deck, go back and clean off the rails and the parapet walls. This makes the structure look better and it keeps trapped moisture from cracking and spalling concrete. One part of the deck I haven't mentioned yet is the joints. Dirt build up here traps moisture, which slowly deteriorates the joint and causes a number of problems from cracking and spalling along the joint to slab separation. So use the water blast to clean out the joint. Obviously cleaning the joint now is a lot easier and cheaper than repairing it later. This is what the deck should look like when you've finished. Clean from the center to the parapet walls and that's cleaning with the inductor. Another deck cleaning method is sweeping, either with a power broom or in this case with a toe type broom. Use as many passes as it takes to clean the entire deck. There are some cases though where brooming can't do the whole job. For example, there's no way a broom could reach underneath this overhanging sidewalk. In this case, you can use the inductor to spray underneath the sidewalk to remove the material. However, the spray nozzles on the inductor may not be powerful or convenient enough to do the job. Instead, you may want to use a handheld spray gun to blast the dirt and debris from underneath the curb. Again, be careful not to wash material back into the middle of the deck. Use enough pressure to build a narrow windrow of dirt and debris. Then vacuum up the material with the inductor, either by using the method you saw earlier or by moving the collector back and forth to pick up the dirt. You can use any method you want. The important thing is that you use the method that's the fastest, easiest and gets the deck the cleanest. And here's the finished job. With the dirt cleaned away from under the curb, there's nothing to trap moisture. So it can drain off the deck like it's supposed to. But it has to have somewhere to go. As you can see here, there's no room for water or anything else in this drainage structure. With nowhere for the water to go, it'll seep into and deteriorate the concrete. So first, remove the grate. But that's easier said than done. This drain is so full of hardened material that the grate is literally cemented tight. That happens when you try to lift it off. So in many cases, you'll have to loosen the material with a water blast and crowbar before trying to lift off the grate. Then when the material is sufficiently loosened, you can lift off the grate. Position the inductor over the drain and turn on and lower the collector. Use the spray gun so the water can help loosen material and aid in suction. Carefully remove any large pieces of debris that could clog or damage the inductor. When the drain is clean, replace the grate. And that's cleaning out the drainage system, which brings us to the end of this program on routine structure cleaning. But as you've seen, there's nothing routine about structures or the importance of keeping them clean. Dirt and water can weaken and eventually bring down even the strongest structure. By properly cleaning, you can prevent a lot of potential damage. If you do notice a problem during cleaning, report it to your supervisor immediately so the problem can be corrected before it's too late. Thank you.