 This is not the right way to patch asphalt road surface defects. The right way takes longer but the patch will last a lot longer. The maintenance handbook covers the proper procedure for patching potholes and that is what this program is based on. Potholes can be patched with just a hand bar, a pick and a shovel. Patching can also be done with power tools that easily attach to a dump truck. In this program we'll learn the correct method of patching asphalt road surface defects and at the same time we'll learn how to use hydraulic and other hand tools. Hydraulic hand tools operate off the hydraulic system of any dump truck that is equipped with an attachment for them. Two hydraulic hand tools are used in this work, the pavement breaker and the tamper. The pavement breaker is used to break out the unsound pavement in and around the surface defect. The tamper is used to pack down the bottom of the cutout hole and the patching material. Here's how the hand tools work. The tool connects to the truck with two hoses. There's a switch on the truck to divert the flow of the hydraulic fluid into the hoses. The pressure of the fluid circulating through the hoses then provides the power for the tool. We'll look at how these hydraulic hand tools are used to patch a road surface defect. But before you start patching, get set up properly. Place all required traffic control and safety devices. Remember these devices protect you as well as the traveling public. In parking your equipment, pay attention to safety by allowing plenty of working space and not blocking traffic. And remember to turn on all your equipment warning lights so traffic knows exactly where you are. The first thing you have to do in the patching operation is to get the hand tools operating. This starts with hooking up the hoses. Connect one end of each hose to the couplings on the truck and the other end to the hand tool. Keep the couplings clean. That's what this spray is for. It is very important that dirt be kept out of the hydraulic system. All hose connections on this equipment are quick disconnect couplings. Next you have to get the truck's hydraulic system working so the tools can be operated. Start the truck's engine and engage the power takeoff, the PTO. The PTO allows the power of the truck's engine to be used by the hydraulic system. The hydraulic system can now be operated. This crew raises the dump box and blocks it to make it easier to get the patching material out of the box. Next switch the diverter valve to change the flow of the hydraulic fluid from the dump hoist to the hand tool hose. To activate the hand tools put the dump hoist lever in the raised position. For proper operation these tools require a fairly constant hydraulic fluid pressure. This pressure is built up and maintained by accelerating the truck's engine. It should run in about 1500 RPMs. The tool is ready to operate. Okay let's go to work. The first step in patching is to mark off the area. Be sure to include about two inches of good material on each side. That way you can be sure you've included all the bad pavement and it will help make the edges of the patch stable. Keep the corners of the patch as square as possible. Some irregular patches will have more than four sides but if you keep the corners as square as possible the patch will have a better chance of holding the material in place. Okay the patch is marked now you can cut it out. The bit we use in this operation is called an asphalt cutter and it does just that. The procedure is to start near the center of the patch and work outward toward the edges. The idea is to relieve the pressure by breaking the pavement on the inside first. If you started cutting at the edge you would damage more of the good pavement. The hole has to be at least two inches deep but cut it as deep as necessary to get a flat stable base. This hole is being cut the full depth of the pavement. Make the corners of the hole as square as possible and the sides as vertical as possible. Holes with square corners and vertical sides stand the best chance of holding the patching material when open to traffic. So be careful when you cut the edge of the hole. Make it straight and most important hold the tool vertical so your cut is vertical. Pay attention to the power you have in your hands here. Hot 200 degree hydraulic oil flowing at 2,000 pounds per square inch of pressure demands respect. Stay away from the hoses as much as you can and always be ready for an accident like a hose breaking or a coupling coming loose. Stay away from that bit too. You see what it does to the pavement. Imagine what it would do to your foot. So protect yourself. Wear steel toe protectors or steel towed shoes. Also wear eye goggles and ear plugs when using hydraulic hand tools. Of course don't forget the standard road worker safety clothing. Orange vests. In general when operating hydraulic hand tools use common sense. Stay alert and be careful. Remove the loose pieces with a shovel. A broom is also necessary to get the smaller pieces out. When you're done chipping and removing all loose material your holes should look like this. Square corners, vertical sides and a flat stable base. At this point you change tools. The tamper looks different from the pavement breaker but it operates about the same. By the way whenever you disconnect the hoses wear gloves. You can't avoid spilling some hydraulic oil and remember when it's working it can get up to 200 degrees. The first job for the tamper is tamping the bottom of the cutout hole. This produces a flat and solid base for the patch. Tamp all parts of the base until it is solid smooth and flat. Before the patching material is placed in the hole the sides and bottom of it must be coated with a liquid asphalt tack coat. This tack coat is a lot like glue. It makes the surface of the hole sticky so the asphalt patching material will bond to it well. After the hole is tacked place either hot or cold asphalt mix in two inch layers. Each layer of the mix must be compacted with the tamper. Always start at the outside and work toward the middle. Holding the tool vertical tamp completely around the hole. Then move in and repeat this process until you reach the center. Tamp all parts of each layer until the mix won't compact any further. The top layer of mix should be struck off with a straight edge. Be extra careful when you're tamping the top layer so that when fully compacted it is flush with the surrounding pavement surface. When the top layer is completely tamped the patch is finished. Again it should be smooth and flush with the road surface. No bump, no dip. After you complete the patching and before you leave the job all excess material should be cleaned up, hauled away and disposed of properly. We've talked about a lot of different things here and some of them may be a little fuzzy right now. Let's bring the whole process into focus with a quick summary of the main points. We're patching asphalt road surface defects with hydraulic hand tools, the pavement breaker and the tamper. These tools operate off the hydraulic system of a specially equipped dump truck. To get your hydraulic hand tools operational hook up the hoses, engage the truck's power takeoff, divert hydraulic fluid to the hand tools by switching the diverter valve, engage the dump hoist lever to activate the tools and accelerate the trucks engine to power them. Now the patching process. Cut out a hole around the surface defect using the pavement breaker with an asphalt cutter bit, a shovel and a broom. The holes should have square corners, vertical sides and a stable base. Tamp the bottom of the hole with a hydraulic tamper. Tack the sides and bottom of the hole with liquid asphalt. Spread asphalt mix in the hole in two inch layers. Thoroughly tamp each layer with the hydraulic tamper working from the outside of the hole toward the middle. Tamp the top layer flush with the pavement surface. When you're finished sweep all loose material off the roadway so that's the right way to patch asphalt pavement defects. If you don't have hydraulic hand tools you can still patch defects the right way using manual tools. The important thing is to do it right so you end up with a good patch that will last.