Performance Evaluation of Transverse High-Performance Concrete Closure Pour Connection for Use in Modular Bridge Construction

Because of the potential for concrete crushing, the negative moment transfer mechanism of the transverse connections above the pier support is still a point of concern. The objective of this study was to evaluate the behavior of a transverse closure pour connection used for the constructed Little Silver Creek Bridge in Iowa and to validate its adequacy for modular bridge application. To evaluate the need for the complicated compression block, two transverse connection specimens with and without the compression block were designed, fabricated, instrumented, and tested under a negative bending moment. Finite element models were established to further understand the specimens’ performance, and hand calculations were performed to estimate their moment capacity. No significant difference was found between the crack patterns of the two specimens, and the diaphragm concrete tended to crush in the bottom regardless of the configuration. The established finite element models were sufficient at representing the structural behavior of the two transverse connection specimens. The connection with a compression block had higher yield and ultimate moment capacity than the connection without a compression block. To design both types of connections according to the classic theory of reinforced concrete design, an effective width equal to the width of the steel girder bottom flange and the centroid of the compression force at the bottom of the steel girder bottom flange can be assumed for the connections with and without a compression block, respectively. Hand calculations reasonably estimated the moment capacity of the two specimens, and the two connections were safe under the codified, factored loads.