Behaviour of composite steel-concrete slabs containing openings

Recently ; and especially since the seventieth, composite form-reinforced floors with cold-formed profiled steel sheetings have become commonly used in modern construction. Moreover,this construction technique is economical. These decks are typically designed for distributedloads and various studies have investigated the behaviour of such floors under this loading. Otherinvestigations spotted on the behaviour of these floors under concentrated loading as resultedfrom wheels of fork-lifts or machinery. AJmost none of previous studies investigated the effect ofopening existence which is a very serious challenge encounters the structural engineers to meetmultitude practical demands such as air conditioning ducts, elevators, stairways, ventilation andemergency holes. This was the main reason which motivated the progress within this research.Because of the expense and the numerous difficulties that associate the experimental realmodeling of such floors, the well-known finite element numerical analysis technique was and stillthe effective tool to solve practical structural and constructional problems. The use offiniteelement technique introduces superior results in most of structural problems, however modelingof actual problems is the most important target in any numerical investigation. Composite slabswere numerically analyzed ; using the SAP 90 program 142] ; assuming linear elastic uncrackedbehaviour of concrete and full interaction between steel sheet and concrete layer. Predicting theideal or at least the best available model was one of the main aims of the current research.A new numerical model simulating the composite slabs using the finite element technique wasdeveloped and based on one-way behaviour simulation (design of steel - deck reinforced slabs isbased upon the load-carrying characteristics ill a one-way direction parallel to the steel-deckcotrugationsi . This modeling technique which named ”Beam-Plate Bending” was numericallytested on different slab panels and the developed stresses and displacements were compared to theresults of a more reliable model of three previously available models of composite slabs in additionto the codes of practice and some available experimental results. Results were evaluatedindicating the high efficiency of the new model.An experimental study has been carried out mainly for the sake of enhancement and detectingthe reliability of the new suggested modeling procedure and to study the structural behaviours ofcomposite slabs ; such as failure modes and crack patterns; under some of main expected criticalcontrolling factors. Four models were experimentally tested under -t-Points Loading System andthen modeled numerically using the pre-mentioned ”Beam-Plate Bending” finite elementmodeling technique.A comparative study between the experimental and numerical analysis results is presented.- ii -