Document Type : Research Paper


Civil Engineering Dept., University of Technology-Iraq, Alsina’a street,10066 Baghdad, Iraq.


Reinforcement interlayer reduces the development of cracks in the asphalt overlay by absorbing the stresses induced by heavy traffic or underlying cracking in the early-constructed pavement. This research is dedicated to studying the behavior of pavement layers on a sand subgrade under simulated effect of earthquake. In this study, the sand layer has a thickness of 600 mm and the base course is taken as 300 mm. The asphalt layer was prepared as a panel with dimensions of 300 × 300 × 50, which represents the surface layer. These layers are experimentally tested under the influence of earthquake loading with different frequencies 0.5, 1, 1.5 Hz. The tests consist of two parts without adding the geogrid, with geogrid in the center of the base layer and between the base layer and sand layer. Loaded stresses in the three layers are monitored using stress gauge sensors, while displacements of the asphalt layer by using displacement gauge sensor. Obtained results considered models reinforced with geogrid, the stress recorded is higher than in unreinforced models but the displacement decreases by increasing the geogrid in the layers at three frequencies. When the geogrid is laid between the base course and sand layer, the stress in the sand subgrade layer is less than that in the base and asphalt layers.


  • The experimental work contains of pavement layers on a sand subgrade under the effect of earthquake.
  • The pavement layers are tested under the influence of earthquake loading with different frequencies.
  • The tests consist of two parts without adding the geogrid, and with geogrid.
  • Stresses in the three layers are measured and displacements of the asphalt layer.
  • For models reinforced with geogrid, the stress recorded is higher than in unreinforced models.


Main Subjects

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