![]() ![]() Poor construction (i.e., inadequate compaction).Inadequate structural design (i.e., the pavement was designed too thin for the anticipated loads).Increase in loading (i.e., the pavement is being loaded more heavily than anticipated in design).The stripped depth contributes little to pavement strength so the effective HMA thickness decreases. Stripping on the bottom of the HMA layer.Water under a pavement will generally cause the underlying materials to become weak. Probably the most common reason is a loss of base, subbase or subgrade support from poor drainage.Decrease in pavement load supporting characteristics.Possible Causes: Inadequate structural support for the given loading, which can be caused by a myriad of things. ![]() Problem: Roughness, indicator of structural failure, cracks allow moisture infiltration into the base and subgrade, eventually results in potholes and pavement disintegration if not treated. After repeated loading, these longitudinal cracks connect forming many-sided sharp-angled pieces that develop into a pattern resembling the back of an alligator or crocodile. As the number and magnitude of loads becomes too great, longitudinal cracks begin to form (usually in the wheelpaths). Severe alligator cracking in a major Honolulu intersection.ĭescription: A series of interconnected cracks caused by fatigue failure of the HMA surface under repeated traffic loading. Severe alligator cracking near the stop line at a major arterial intersection. ![]() Please contact your state DOT or Pavement Association for assistance. There are always exceptions to the rule – the exact condition you are looking for may not be here. Index of Pavement Distressĭistressed pavement is often a result of a combination of factors, rather than just one root cause. Photos of each type of distress are accompanied by a description of the distress, the reason it is a problem, some of the most likely causes and basic repair strategy. If you are looking for a specific type, scroll down and look at the thumbnails to see which picture most closely matches the condition you are investigating. This section is organized alphabetically by type of surface distress. Provide some basic guidance into what kinds of conditions might lead to certain surface distresses.Provide some insight into why particular surface distresses are problematic.HMA pavement damage that is visible at the surface of the pavement is often called “surface distress”. Assist in identifying basic HMA pavement damage.However, like all pavements, HMA pavements can be damaged by certain conditions. Effective Date: 04/03/03 Revised Date: 01/12/05 Contact Person: Tom Zehr / Phone: 217/524-7268 / Email: Superpave Bituminous Concrete Mixtures (Low ESAL), Rubber Modified (CBM) Application: For HMA projects containing crumb rubber modified asphalt cement.Properly designed and maintained HMA pavements can provide many years of satisfactory service. Special Provision For Anti-Stripping Additives in Bituminous Mixtures For Extended Life Pavements (CBM) Application: Premium HMA anti-strip additive to be used in all Extended Life Pavement Projects and in all projects where hydrated lime is specified.In addition, these specifications are a working document and have not been adopted as a statewide standard. Since these activities are under development or are being evaluated, the specifications do not have a wide distribution. Administration of these activities requires CBM to develop new specifications or revise existing department specifications. Activities involving materials, research, and new products are administered by IDOT's Central Bureau of Materials (CBM). ![]()
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