The main objective of this study was to investigate the speed effect of vehicles on the Hot Mix Asphalt. These effects were determined in terms of permanent deformation (rutting) and cracking since they are the major distresses in flexible pavement, which are caused due to overloading, speed of vehicles and high temperature variation. In this study, a total of 12 samples were prepared by Marshal Compactor. The Uni-axial repeated creep tests were carryout using a Universal Testing Machine (UTM-5P). The testing were done on asphalt samples for loading pulse period duration of 1,500 ms and pulse width of 200 ms (0.2 sec), 400 ms (0.4 sec), 600 ms (0.6 sec), 800 ms (0.8 sec), 1000 ms (1 sec) and 1,200 ms (1.2 sec). Two replicate samples were tested under each pulse width. The temperature was kept constant for all the samples, which was 40ºC. It was observed that with the increase in pulse width (i.e. loading time) the resilient modulus decreases. This is due to asphalt concrete behavior as visco-elastic material; which behaves like the elastic material at fast moving loads and then behaves like viscous material at slow moving loads. Hence increment in vehicle speed causes the pavement failure pre-maturely. Similarly, with the increase in pulse width the accumulated strain increases, which indicates that the low speed vehicles cause permanent deformation (rutting) to asphalt pavements.
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