Reflective cracking is the major distress in composite pavement and can accelerate the deterioration of the whole structure. This paper analyzes the potential for reflective cracking in composite pavements because of thermal cycles. A heat transfer model was first developed to predict cyclic temperature variations with climatic inputs (solar radiation, wind velocity, air temperature, and humidity). Mechanical models were then employed to analyze thermally-induced reflective cracking potential using fracture mechanics parameters. Both models were validated through field measurement of temperature profile and crack propagation. The temperature profile in composite pavement can be predicted accurately from climate data and typical thermal material properties. Because of the temperature variation and gradient in composite pavement, concrete slabs undergo joint opening and curling deformation and stress concentration occurs at the bottom of the overlay. The loading cycles for initiation and propagation of reflective cracking were predicted by empirical equation and Paris’ law. Increasing overlay thickness can extend the pavement service life, but care is needed as different thicknesses offer varying efficiency. Thicker asphalt overlay mitigates reflective crack potential, especially at the crack initiation phase.
Finite element simulations of thermally induced convection in an enclosed cavity