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Abstract:
Pavement distresses are those defects visible on the pavement surface. They are symptoms, indicating some problem of pavement deterioration such as cracks, patches, potholes, ruts among others. The distresses increase journey times, operating costs, transport fares. A well maintained road increases safety and ride quality. The methodology used was the visual condition survey whereby a pilot survey, was first carried out on foot in order to confirm the level or severity of damage, after which a digital camera was used to take the photographs of the defects, and then classifying them into types. Soil analysis of the subgrade was carried out in accordance to B.S. 1377. All the portions of road studied are in very poor condition. They are beyond rehabilitation. The study found that the Compaction test falls between 191.64kg/m3 and 1302.4kg/m3, Optimum moisture content falls between 7.8% and 28.9%, California bearing ratio (soaked) falls between 11% and 45%, unconfined compressive strength falls between 32.4KN/m2 and 486.7KN/m2. The study also found that the main defects on the road are potholes, edge cracks, transverse cracks, longitudinal cracks and fatigue cracks. The study concluded that the probable causes of the defects may be due to inadequate or lack of drainage, poor design and poor workmanship, lack of corrective and preventive maintenance, increased and repeated loading which is greater than what the pavement was initially designed to carry. The study recommended that based on the fact that the pavement's deterioration is beyond rehabilitation, it should be redesigned and reconstructed.
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