Experimental and numerical investigation of dowel bar misalignment in thin rigid pavement joints

Abstract

Dowel bars transfer loads across transverse joints in jointed plain concrete pavements while allowing joint movement. Angular misalignment can increase restraint and local stresses at the dowel-concrete interface. Previous studies have mainly focused on thicker highway and airport pavements with relatively large dowels, while thin rigid pavements with smaller dowels remain less studied. This study experimentally and numerically investigates dowel misalignment in 150 mm thick concrete slab pairs connected by a 20 mm diameter steel dowel. Six specimens representing aligned, horizontal, vertical, and combined misalignment conditions were tested under progressive horizontal displacement. A three-dimensional nonlinear finite element model incorporating Concrete Damaged Plasticity (CDP) and dowel-concrete contact was developed. Misalignment generally increased pull-out resistance and local stress concentration; the 6.3° vertical case produced the highest experimental resistance of 7.5 kN and the most pronounced tensile damage. Excluding the compromised H3.1 test, the model reproduced the aligned and single-plane peak loads within 4.0-15.6%. The findings indicate that vertical misalignment requires particular construction control because increased joint restraint and localised damage may contribute to premature joint deterioration.