A New Algorithm for Determination of Crack Growth Path in HMA Materials
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In this paper, a new algorithm is presented for determination of the crack growth path in hot mix asphalt (HMA) materials. In a newly developed fracture simulator, the pavement structure is modeled with a viscoelastic boundary element method, which provides an attractive alternative to finite element-based methods for modeling crack initiation and growth. According to the HMA fracture mechanics, a fundamental energy-based threshold is used to determine crack growth and the direction of crack growth, and viscoelastic mixture properties are used to determine the rate of crack growth. To determine where a crack propagates, a grid in the critical zone is defined to cover a range of possible crack growth directions and locate the direction of the maximum dissipated creep strain energy (DCSE). The crack will propagate in the direction of the maximum DCSE when the DCSE in this direction reaches the damage threshold. The fracture simulator is shown to predict top-down crack growth patterns in hot mix asphalt pavements observed in the field.