Bridge Decks with Precast UHPC Waffle Panels: A Field Evaluation and Design Optimization

Abstract

The first full-depth precast ultrahigh-performance concrete (UHPC) waffle panels have been designed and implemented in a bridge replacement project to use accelerated bridge construction and increase bridge deck longevity. This paper first evaluates the structural performance of this bridge using a combination of field live-load testing and analytical modeling. The collected data for vertical deflections and strains at discrete critical locations on the bridge deck, subjected to static and dynamic truck loads, demonstrated satisfactory performance of the bridge deck and correlated well with the results obtained from the analytical model. Thereupon, options to optimize the bridge deck are examined to minimize the UHPC volume and associated labor costs. Using the analytical model, an optimization of the waffle panels was undertaken by varying the number of ribs as well as spacing between the ribs. An optimized panel was achieved by reducing the interior ribs per panel from four to two, or zero, in the longitudinal direction and six to two in the transverse direction, without compromising the panel’s structural performance.