Laboratory and Field Testing of Precast Bridge Elements Used.pdfVIP

Laboratory and Field Testing of Precast Bridge Elements Used for Accelerated Construction Vernon W. Wineland Iowa State University 176 Town Engineering Building Ames, IA 50011 vernonw@iastate.edu F. Wayne Klaiber Iowa State University 176 Town Engineering Building Ames, IA 50011 vernonw@iastate.edu Thomas P. Schoellen Black Hawk County Courthouse 316 East Fifth Street, Suite 211 Waterloo, IA 50703 tschoellen@co.black-hawk.ia.us ABSTRACT Black Hawk County (BHC) has developed a precast modified beam-in-slab bridge (PMBISB) system for use with accelerated construction. Individual components of the system have been tested in the Iowa State University Structural Laboratory, and the overall system was tested in the field. Using the BHC system, the bridge superstructure can be assembled in two days and the bridge opened to traffic as soon as the cast-in-place concrete connection between the precast panels has reached the required strength, which is usually one week. Precast components tested in the laboratory include two precast abutment caps, three different types of deck panel connections, and a precast abutment backwall. Load testing on the first abutment cap revealed that it had considerably more strength than was required. Therefore, the cap was modified to be more efficient. The original PMBISB panel connection was inefficient in the amount of time and concrete needed for construction. Thus, three other panel-to-panel connection designs were tested in the laboratory, one of which has already been used in the field. The final laboratory work was the service load and ultimate load testing of a precast abutment backwall panel. Field testing of the first precast bridge (L = 40 ft., W = 32 ft.) in Black Hawk County was performed in June of 2007. The testing investigated service load stresses, lateral load distribution characteristics, and overall global behavior of the system. This paper presents the results of the laboratory and field te