Evaluation of dowel bar diameter and spacing effects on the stress and deflection of airfield rigid pavements using the finite element method

Mitigating the effects of thermal stress and shrinkage in airfield concrete pavements typically involves dividing the pavement into individual slabs of appropriate dimensions. Under aircraft wheel loading, the slab edges and corners are subjected to the most critical and unfavorable stress states. To reduce these disadvantages, dowel bars must be placed along both the longitudinal and transverse joints to transfer part of the applied load from the loaded slab to the adjacent one. Improper selection of dowel diameter or spacing can significantly diminish the pavement’s load-bearing capacity and shorten its service life. In this study, the finite element software ABAQUS was used to examine the influence of dowel bar diameter and spacing on the stress and deflection responses of airfield concrete slabs subjected to B737-500 aircraft loading. The numerical model considered two commonly used slab thicknesses: 0.30 m and 0.40 m. The results indicate that, for a constant dowel diameter, the deflection and stress increase sharply as dowel spacing increases from 0.1 m to 0.4 m, while changes become negligible beyond 0.40 m. Conversely, when spacing is kept constant, increasing the dowel diameter from 20 mm to 40 mm substantially reduces stress and deflection, with further increases yielding minimal additional benefit. These findings provide useful guidance for selecting appropriate dowel dimensions in the design of airfield concrete pavements