Dowel — Concrete Interface Material Categorization & Performance in Isolated Test Slabs

The Minnesota Department of Transportation (MnDOT) investigated the use of dowel bars with various anchoring methods. This report examines the characteristics of various epoxy and grout anchorage systems at the interface between new construction and existing concrete. Twelve different anchoring materials as well as various anchoring methods were studied and compared to a control using no grout. This study did not examine the effects of the number of dowels used but instead was limited to the methods and materials used to anchor the dowels. This experiment was performed on concrete panels in-house. The tube grout method exhibited the best visual and magnetic imaging results. The evaluation methods did not clearly categorize the materials in order of performance but showed advantages of cleaning the drill-hole prior to dowel placement as well as the merits and demerits of using a retaining collar. The results generally suggested the need for an actual deployment research project on actual pavement in real-world service conditions. The field experiment was reported in a separate document.