Uniform Serviceability Load Limits for Mechanical Flange Connectors

Multilevel parking structures are often constructed using prestressed concrete double-Tee beams that form their floor and roof diaphragms. Mechanical flange connectors are typically used to connect the flanges of these beams. Cracking of the concrete around the connectors is a common problem requiring significant person-hours to repair and maintain. This paper presents suggested design load levels that may significantly reduce the cracking in these structures based on the results of 49 monotonic displacement control tests performed on 6 different types of commercially available mechanical flange connectors embedded in concrete slabs. The slabs were designed to be representative of the overhang on a typical precast concrete double-Tee beam. Three different types of monotonic tests were performed: horizontal shear, vertical shear, and tension. Basic statistics were then used to analyze the data from each of these three test types and the load ranges were divided into four regions, termed cracking unlikely, cracking possible, cracking likely, and cracking probable.