Experimental and Analytical Investigation of an Innovative Composite Shallow Floor Framing System

Abstract

Since the early 1950’s, composite concrete-steel systems have been a popular and economic choice for floor construction in the United States. The conventional composite floor system comprised of a concrete slab with light gauge steel deck form supported by wide flange structural steel girders has been widely used in construction. In recent years, modifications to the conventional system have been made to meet a market need for floor systems with reduced structural depth to be used in a variety of building types including office buildings, hotels, and hospitals. In 2007, Diversakore® LLC developed the Versa :T:TM beam, an innovative shallow floor composite framing system that utilizes a small structural depth and also makes improvements in the ease and speed of construction. The system includes a u-shaped steel plate which supports hollow core plank flooring during construction and serves as a stay-in-place form for a cast-in-place reinforced concrete girder. The concrete girder is cast monolithically with a topping slab to engage the hollow core planks and the u-shaped steel section into a composite t-beam. A research program to evaluate the performance of this innovative floor system has been developed and is currently ongoing at the Constructed Facilities Laboratory at North Carolina State University in Raleigh, NC. The experimental and analytical program includes full-scale tests of representative sub-assemblages and utilizes a layered sectional analysis to predict the behavior. The results of the analytical model and the experimental investigation are presented along with conclusions drawn from the initial phase of the research program.