Date of Award
Master of Science
Dowel bars are a useful tool for transferring loads from one concrete slab to another across joints. Dowels have usefulness in highway slab and building slab applications. While dowels are used to increase load transfer capabilities across joints, they also introduce new problems, including stress concentrations and corrosion. Most dowel bars have circular cross sections. The regions of stress concentration for circular dowels are at the top and bottom of the cross section. Therefore, the sides of the dowel give little aid in providing bearing against dowel loading. Circular steel dowels have performed well in handling stress concentrations. However, alternative materials and shapes may perform better. Much research has been conducted at Iowa State University and nationally concerning the performance of dowels with various parameters. Parameters include dowel material, dowel shape, joint width, and dowel spacing and have been used to evaluate bearing stress performance. Laboratory testing, field testing, and finite element analysis have all been performed to study these parameters. Altogether, ten types of dowels were tested. The six highway dowels studied were adequate to transfer load. Cost and environment are criteria that should be considered when choosing among these six dowel types. All four of the building slab dowel types studied were able to transfer a load of at least 3000 pounds between adjacent slabs without a factor of safety (an appropriate factor of safety should be applied as deemed necessary by a jurisdictional authority). Slab thickness, dowel spacing, and dowel cost should all be considered when selecting among these four dowel types.
Nathan Joel Pierson
Pierson, Nathan Joel, "Parametric effects on concrete-dowel behavior" (2006). Retrospective Theses and Dissertations. 19091.