Assessment of Bridge Technologies through Field Testing: In-Situ Load Testing of Bridges B-20-148 and B-20-149, Fond du Lac, WI

The scope of this project was the evaluation of two twin bridges having numbers B-20-148 and B-20-149, respectively, located on US Highway 151, in Fond du Lac County, Wisconsin. Bridge B-20-148 was constructed utilizing a cast in place Fiber Reinforced Polymer (FRP) Reinforced Concrete (RC) deck while Bridge B-20-149 was built using a conventional cast in place RC deck. To better evaluate the load-carrying capacity of the bridges, a nondestructive field test was conducted. The bridges were tested statically using six dump trucks. The bridges' deflections were measured using a Robotic Tacheometry System (RTS), while the strains at critical locations were measured by means of electrical resistive strain gages. The RTS is a noncontact deflection measurement technique that offers the capability to measure the spatial coordinates of discrete points on a structure in three dimensions without having to touch the object. A finite element method (FEM) model was developed to represent the behavior of the bridge and was used to determine the actual load rating of the structure and its safety over time. The comparison between analytical results obtained according to AASHTO standard specifications, FEM modeling and experimental study allowed establishing a good understanding of the bridges' performance.