Girder–Deck Interface: Partial Debonding, Deck Replacement, and Composite Action

Abstract

Results are reported from tests of three precast/prestressed concrete girders under fatigue-type cyclic and monotonic loading conducted after deck removal and replacement. Although deck demolition altered the top surface of the girders, the girder-deck interfaces exhibited shear strengths greater than their nominal capacity (based on the 2012 AASHTO LRFD Specification) after 2×10 6 cycles of loading to 45 and 30% of their nominal strength for troweled and roughened interfaces, respectively. A partially debonded detail was used for two of the girders to protect the girder top flange, which was wide and thin, during deck demolition. The roofing felt used to debond the girder-deck interface over the flanges reduced the effort required for deck removal by 65% compared with the typical detail, eliminated chipping-hammer induced damage to the girder flanges, and still resulted in sustained composite action under 2×10 6 cycles of loading. The width of bonded interface had little effect on girder stiffness and no observed effect on the width of deck effective in bending.