 Potholes are caused by weak spots in roads. These weak spots can be created by heavy vehicles, poor construction, or water. This videotape will show you how to repair potholes in surface treatment pavement using granular material. If you're using asphalt mix, referred to the IRF videotape, pothole repair in asphalt concrete pavement. Regardless of their location, all potholes can be a threat to your safety and damage your vehicle. But most importantly, potholes can result in severe and costly road damage if they're not repaired quickly and correctly. Surface treatment pavement is not as strong as asphalt concrete pavement. Therefore, these potholes must be repaired before they become so large that the road base is weakened. Extensive repairs would then be necessary. A repair using the correct procedures will keep water from getting into the road base, resulting in a long-lasting patch. Proper equipment will help you make the repair efficiently. You will need hand tools for removing damaged material from the pothole, placing the new material, and cleaning up the work site. An asphalt sprayer for applying the liquid asphalt, and a vibratory roller to make the materials firm. You can also use a vibratory plate compactor or a tandem steel-wheeled roller. You'll need a dump truck to carry your crew, equipment and materials to the work site, and traffic control devices to keep vehicles moving safely. The proper materials make the repair durable and long-lasting. You will need granular material to fill the hole. It must be graded and approved according to local specifications. This material should be the same type and quality as the existing base. You will also need cover aggregate that is clean, dry and no bigger than your thumbnail. Liquid asphalt to seal the patch. The liquid asphalt may be rapid or medium curing asphalt cutback or asphalt emulsion. And water to make sure the granular material has the correct moisture. All potholes in surface treatment roads are repaired in the same way. You will use the same procedure for all shapes and sizes of potholes. There are eight steps. Step one, place the traffic control devices. Step two, mark the damaged area. Step three, cut out and remove all damaged material. Step four, fill the hole with granular material. Step five, compact the granular material. Step six, seal the surface with liquid asphalt and cover aggregate. Step seven, clean the work site. Step eight, remove the traffic control devices. We will look at each step in detail. Step one, place traffic control devices. These include barricades, cones and signs. Proper placement of these devices is important to the safety of your crew and the vehicles. Place these devices so that the vehicle drivers have adequate time to respond. For further instruction, refer to the IRF videotape, traffic control during maintenance. Step two, mark the damaged area to be repaired. Before you mark this area, clean out the pothole so you can inspect it. Clearly mark the pavement outside the pothole. To avoid waste, the line should be no further from the hole than the width of your hand. The line should also be straight and located in good pavement. The corners should be as square as the shape of the hole will allow. Step three, cut out and remove the damaged material. Use a pickaxe and shovel. Start in the center and work toward the sides. Remove all material necessary to reach a firm, flat bottom. Remove damaged material with a shovel. Do not forget to dispose of this material away from the pavement and nearby ditches. Proper disposal will help keep the pavement clear for vehicles. The sides should be straight and vertical to the flat bottom. Check this in several places. The straight sides and a flat bottom will make the finished repair last a longer time. Also, be sure the sides and bottom are firm. Step four, fill the hole with granular material. Before placing the granular material in the pothole, check for proper moisture. Squeeze a sample in your hand. If it is too dry, the granular material will crumble. Water must then be added to correct the dryness. A sample has correct moisture if it forms a tight, compact ball when you squeeze it. If the sample is too wet, it will flow very slowly between your fingers when you squeeze it. In this case, the granular material should be spread out to dry. Next, check the depth of the hole. If the hole is less than 15 centimeters deep or shorter than the length of your hand, the granular material can be placed in a single layer. If the hole is deeper than 15 centimeters or longer than the length of your hand, the granular material must be placed in two or more equal layers. Each layer should be no thicker than 15 centimeters. Step five, compact the granular material. Place wooden planks on the edges of the hole to protect the sides. If using a vibratory roller, make two passes without vibration, then make 10 to 12 passes with vibration. Start from the corners and work toward the center. Compact each layer thoroughly. If using a hand tamper, make the layers half as thick. Compact the granular material until it is as firm as possible. After compacting the last layer of granular material, make sure the repair is rounded slightly above the surrounding pavement. This will help keep water from entering the road base and damaging the pavement structure. Step six, seal the surface with liquid asphalt and cover aggregate. To begin this process, apply the liquid asphalt using an asphalt sprayer or an asphalt pouring pot if you do not have an asphalt sprayer. The surface must be clean and dry. Make the application thick enough to soak into the patch and form a light coating over it. Overlap the asphalt onto the existing pavement 8 centimeters or the width of your hand. Immediately after applying the asphalt, spread a single layer of cover aggregate across the surface of the patch. Now compact the aggregate so it locks together properly. Continue compaction until the aggregate has been well embedded in the asphalt and a uniform surface obtained. Make sure the surface of the patch is smooth and rounded slightly above the surrounding pavement about the thickness of a pencil. Step seven, clean the worksite. Sweep and dispose of any debris away from the drainage ditches, the shoulder, and the pavement. The road will be safer. Before you leave the worksite, load any unused material, equipment, and hand tools into the truck. At the end of the day, clean your hand tools before you load them. Step eight, pick up the traffic control devices and load them on the truck. Do this in the reverse order of their original placement. The maintenance crew is now ready to proceed to the next worksite. But before they go, remember there are eight steps necessary to repair potholes in surface treatment pavement. Step one, place the traffic control devices. Make sure the signs, cones, and barricades are placed correctly. Step two, mark the damaged area. Make the lines straight and the corners square. Step three, cut out and remove all damaged material. Keep the sides straight and vertical to a flat bottom. Step four, fill the hole with granular material. Place the material in even layers. Step five, compact the granular material. Make each layer as firm as possible. Step six, seal the surface with liquid asphalt and cover aggregate. The asphalt application should be even and slightly overlap the surrounding pavement. The cover aggregate should be compacted thoroughly. Step seven, clean the worksite. Dispose of all debris away from the road and nearby ditches. Step eight, remove the traffic control devices. Pick them up in the reverse order of their placement. The procedure you have just seen will provide a long-lasting repair which will preserve the road structure and make travel safer for everyone.