Mitigating Reflection Cracking in Asphalt Overlays using Geosynthetic Reinforcements

ABSTRACT A coordinated laboratory and numerical investigation was conducted to simulate the growth and propagation of reflection cracking in asphalt overlays reinforced with stiff geosynthetic inclusions. The objectives of this research were: (a) to evaluate the behavior of asphalt overlays placed over concrete joints under cyclic loadings; (b) to assess the effects of construction conditions and placement locations of the geosynthetic layers within the overlay; and (c) to determine the effects of debonding between the AC and the underlying concrete pavement on the inducement of critical stresses. Results indicate that for all testing conditions, specimens reinforced with high stiffness geosynthetics offered greater resistance to reflection cracking when compared to unreinforced specimens. ABAQUS finite element analysis suggested that the Von Mises stresses in the AC layer are significantly higher when the layers are debonded, and that the Von Mises stresses can be meaningfully reduced by placement of stiff geosynthetics at the bottom of AC layer.