 Proper maintenance of roads is necessary to preserve your nation's highway network and reduce transportation costs to keep the roads in good condition. It is very important to perform proper maintenance when it is first needed. Understanding the causes of common maintenance problems produces a better understanding of the repair tasks. Proper repairs made on a timely basis will prevent further deterioration, requiring more extensive and costly repair. This videotape focuses on common maintenance problems and causes. As the foreman, you must understand the cause of a problem before you can plan the proper maintenance operation. We will show you common maintenance problems and their causes for seven maintenance areas. Asphalt pavement, Portland cement concrete pavement, earth and gravel roads, road shoulders, drainage facilities, bridges, and roadside areas. For these seven maintenance areas, water causes most major problems. Water which is blocked by debris in drainage facilities will saturate the base and subgrade material. If water does not drain properly, it will enter the road base through surface cracks or holes and damage the base, subbase, and subgrade. A saturated road will deteriorate further until it is properly repaired. Another major cause of road damage is the weight of vehicles. Repeated excessive heavy loads will produce defects in all types of pavement. Also insufficient compaction of pavement courses causes the road surface to deteriorate quickly. If the pavement courses are not compacted adequately, surface defects will develop. If poor quality materials are used to repair the road, the repairs will not last very long. If defects are not treated while they are still minor, they will become serious problems. We will take a closer look at problems affecting each of the seven maintenance areas. Also, we will see their specific causes. Asphalt concrete pavements and surface treatment pavements have similar maintenance problems. Over time, vehicles on the road will make the surface aggregate smooth, creating a slippery surface. The loss of cover aggregate can be caused by using dirty or wet aggregate. It can also be caused by the asphalt cooling too much before the aggregate is spread on top of it. Or if the aggregate is not compacted immediately after it is spread. Bleeding is recognized as a shiny film of batuminous material on the pavement surface, caused by too much asphalt in any layer of pavement. Corrigations are recognized as a series of closely spaced ridges on the pavement. Corrigations result from the paving mixture having too much asphalt, too much fine aggregate, or aggregate that is too round, as well as asphalt cement, which is too soft. Ruts are surface depressions developed in the wheel path. They have the same causes as corrugations. Poor compaction and poor quality materials will cause shoving, which occurs when a specific area of pavement has been permanently displaced under the weight of vehicles. Depressions are identified as pavement areas that are slightly lower than surrounding pavement. Traffic, heavier than the pavement's bearing capacity, causes depressions. They are also caused by settlement of the lower pavement layers, or by poor construction methods. If any of these hazardous surface defects are not corrected, cracks or breaks in the pavement may develop. Cracks are also caused by inadequate support of the road base. Pavement, which is too thin, shrinkage of surface materials, the age of the pavement, or by poor quality materials and construction methods. If water saturates the base and the subgrade through these cracks, potholes may develop. Also, if depressions in surface treatment and asphalt concrete pavements, which are caused by a weakened base, are not repaired, or if water has saturated the base, traffic will cause potholes, by helping to break up the weakened pavement surface. If water continues to saturate the base, subbase and subgrade, the whole pavement structure will fail. When this happens, the subgrade, subbase, base and surface must be replaced. Let us look at problems associated with Portland cement concrete pavement. Common types of failure in Portland cement concrete pavement are polished aggregate, caused by repeated traffic, reduces the friction necessary for tire adhesion of vehicles. Cracks are caused when the concrete shrinks due to improper curing, or when the subbase or subgrade expands due to water saturation. Also, heavy vehicles on poorly supported slabs will cause cracks. Scaling is the peeling away of the pavement. Scaling results from the use of de-icing salts, improper mixing or curing of materials, or the use of unsuitable aggregate. Scaling is the breaking or chipping of the pavement at joints, cracks or edges. Scaling develops when gravel becomes lodged in a crack or joint, when there is poor installation of load transfer devices at the joints, when there are poorly formed or sawed joints, or when weak mortar is used in construction. If scaling and spalling are not promptly repaired, they may become holes in the pavement. The combination of heavy vehicles and a saturated subbase or subgrade will cause pumping. Pumping is the concrete slab movement along joints and cracks under passing traffic, resulting in the ejection of a mixture of water, sand, clay and silt. If not repaired, pumping may cause faults. They are recognized as a difference in elevation across joints or cracks. This defect is also caused by an insufficient load transfer between slabs, as well as shrinkage of the underlying course. Earth and gravel roads have different problems than paved roads. However, most of their problems are caused by water. Also, heavy vehicles and wind will erode unpaved roads. Loss of the roads crown is the most common problem on unpaved roads. Corrigations, ruts and potholes are other serious maintenance problems on unpaved roads. Gullies are caused by water running on the road surface. Soft spots on unpaved roads are low areas where water accumulates and saturates the subgrade. This weakens the road. Soft spots must be repaired to prevent serious damage. Let us look at problems and their causes for road shoulders. Paved road shoulders have the same problems and causes as paved roads. They may be deteriorated due to a loss of cover aggregate, cracks or potholes. Earth and gravel road shoulders have different problems than paved road shoulders. Water and heavy vehicles cause problems on unpaved road shoulders, such as a loss of cross slope, shoulder drop off, erosion gullies and ruts. Vegetation growth and material buildup on shoulders will prevent water from draining off the road properly. Drainage facilities, which are not maintained properly, can cause many problems on all types of roads. Water, which cannot drain through drainage facilities, causes serious problems, such as cracks and potholes in paved roads and ruts and soft spots in unpaved roads. Poor drainage may be caused by unlined ditches, which have a cross section that is too small, a loss of shape, collapsed sides or accumulated debris and vegetation. Lined ditches with damaged linings or accumulated debris also cause poor drainage. Culverts restrict the flow of water by having their inlets, outlets or their interiors blocked by debris and vegetation. Also, breaks in the culvert will weaken the surrounding area and may cause the road to wash out during the rainy season. Catch basins filled with silt and debris inhibit proper drainage and cause water to accumulate on the road. Also, cracks in their structure will allow water to weaken the surrounding area. We will look at maintenance problems and causes associated with bridges. Concrete bridge decks have some surface problems and causes similar to Portland cement concrete pavement. These similarities include cracking, scaling, spalling and holes. However, bridges have unique problems as well. Exposed and corroded steel on steel bridges weakens their overall structure. Loose planks caused by inadequate nailing on a timber bridge deck are a safety hazard to traffic. Rot caused by aging or improper treatment also makes timber bridges unsafe for traffic. Accumulated debris on bridge decks can block drainage holes and expansion joints. Also, accumulated debris on the bearing areas of abutments and pier caps will prevent the bearings from functioning properly. Debris will accumulate under bridges, restricting the flow of water and endangering the safety of the bridge structure. High water current and accumulated debris can cause erosion around the abutments. And last, roadside areas present several maintenance problems for roads. Overgrown roadside vegetation will hinder proper drainage and may obscure the visibility of road signs. If water seriously erodes an embanked section of the road, the road will become weakened or may be partially displaced. On unstable slopes of cuts and embanked sections, slides may occur during the rainy season. Remember, water, heavy vehicles, poor construction and maintenance methods, and poor quality materials cause most common maintenance problems, which include cracks, depressions, and potholes in asphalt pavements. On Portland cement concrete pavement, these problems include cracks and spalling. Major problems on earth and gravel roads include corrugations, ruts, and potholes. The most common maintenance problems on road shoulders include erosion gullies, shoulder drop-offs, and vegetation growth and material buildup. Debris in drainage facilities such as ditches, culverts, and catch basins are responsible for restricting the flow of water. The major problems on bridges include surface defects, blocked drainage, and bearings blocked with dirt and debris. The most common problems in roadside areas are overgrown vegetation, slides, and embankment erosion. The IRF training aids will help you make the best use of your workers, equipment, and materials to repair these problems and maintain your roads properly.