Development of a new long span composite floor system

This paper presents the results from the testing of a prototype for a new long-span composite floor system known as Tekdek. The tested prototype achieved a clear unpropped span of 10.5m, which is significantly greater than any other comparable composite system currently on the market. The system introduces a new concept of prestressing the steel deck prior to pouring the concrete. The prototype deck was tested to investigate its ultimate compressive prestressing capacity and its performance under pouring of the concrete to form the completed composite system. In addition, the constructed composite floor system was tested under vibration, cyclic and ultimate load. The performance when pouring the concrete, and the tests on the composite system, were repeated for two different decks (designated A and B) which were subjected to different prestressing loads. It was found that the composite system, based on a one unit width, had a fundamental frequency between 4.4 and 4.5Hz and achieved a maximum load carrying capacity between 9.0 and 9.87kN/m 2, which is acceptable for most buildings. An indicative fire test provided the temperature distribution through the cross-section, when subjected to the standard fire curve, allowing the fire resistance of the system to be estimated.