Load-Deflection Behavior of Smooth Dowels

Transverse joints in pavement structures accommodate contraction, expansion, and interruptions in construction. Mechanical load transfer devices, such as dowel bars, are often used in rigid pavements to transfer force from a loaded slab to an adjacent slab. An experimental study was conducted to investigate the effect of concrete strength, dowel diameter (smooth dowels), and joint width on transverse deflections of loaded dowels. Instrumentation was developed to measure the deflected shape of a portion of a dowel embedded in a slab. Laboratory mockups of pavement joints containing concrete with three nominal compressive strengths, three different dowel diameters, and two different joint widths were tested. Results indicated differences between measured dowel deflections and deflected shapes from those predicted by a widely used equation for a prismatic bar resting on an elastic foundation. Agreement between theory and the tests was also found to be quite sensitive to an elastic parameter used in the prediction equation.