Analysis of Reflective Crack Control System Involving Reinforcing Grid over Base-Isolating Interlayer Mixture

Abstract

To develop a rigorous, mechanistic design method for asphalt overlays, one must have a method to accurately determine the response of the overlay system to various load conditions. This paper presents a cutting-edge nonlinear three-dimensional finite-element modeling approach for asphalt overlay analysis, including a viscoelastic constitutive model and realistic traffic and environmental load conditions. These tools were used to analyze a proposed reflective crack control system for Taxiway E at the Greater Peoria Regional Airport (GPRA), involving a base-isolating interlayer mixture used in conjunction with a glass-fiber reinforcement layer. The use of a base-isolating interlayer below the asphalt overlay was found to greatly reduce tensile and shear stresses in the asphalt overlay. Based upon expected critical cooling events and design aircraft at GPRA, critical overlay and interlayer stresses were found to be predominantly load associated. The base-isolating interlayer was predicted to develop localized stresses in the vicinity of the existing crack well beyond the yield threshold, based upon linear viscoelastic analysis. This suggests the importance of designing a tough, ductile interlayer mixture that can tolerate localized yielding under repeated load applications.