Slab-Type Modular Bridges Analytical Study on a Longitudinal Joints of the

In this study, a longitudinal joint connection was proposed for the short-span slab-type modular bridges with rapid construction. The slab-type modular bridge consists of a number of precast slab modules and has the joint connection between the modules in the longitudinal direction of the bridge. A finite element based parameter analysis was conducted to design the shape and the dimensions of the longitudinal joint connection. Numbers of shear keys within the joint, height and depth of the shear key, tooth angle, and the spacing were considered as the design parameters. Using the local cracking load at the corner of the shear key and the cross-sectional area of the joint, an efficiency factor was proposed to evaluate the effectiveness of the longitudinal joint connection. The dimensions of shear key were determined by comparing the cracking loads and the efficiency factors obtained from the finite element analysis. RECAST slab bridge is a suitable bridge type for the construction especially in urban area, where a severe traffic jam may occur during the construction. The national bridge inventory in Korea indicates that, among the bridges over 30 years in service, 87% of them are the short-span bridges. Their span length is less than 20 m (1). It is expected that the demand for the replacement of the short-span bridge will be dramatically increased in the near future. A slab-type modular bridge has been proposed in this study in order to prepare the demand for the replacements of the short-span bridges. The slab-type modular bridge proposed in this study consists of a number of precast slab modules segmented in the transverse direction. The modules are connected by filling the longitudinal joints between the modules with high strength mortar and prestressing tendons in the transverse direction. The nominal compressive strengths of the concrete used for the precast modules and joints are 50 MPa and 80 MPa, respectively. The curing time of the filling concrete required to develop 80% of