Two different large-scale industrial structures that were destroyed by fires in 2011 and 2012 in Turkey were examined. The structural framework in the first structure was constructed as prefabricated concrete, while a prefabricated concrete–steel (hybrid) was the structural framework in the second. The post-fire performance of the structures was evaluated according to the structural system properties of the buildings and tests on concrete core and steel reinforcement samples obtained from the structures. Since the fire durations of the two buildings examined were slightly different, in addition to the structural framework differences, material test results were comparatively interpreted for the two structures. The concrete used in the building exposed to the longer fire duration suffered a substantial loss in mechanical properties, the concrete cover in the reinforced concrete elements failed completely, and there was a significant loss in the yield strength of the steel reinforcement. In the second structure, which experienced a fire of shorter duration, although the concrete cover had failed similarly to the first case, there was not a substantial loss in the mechanical properties of the reinforcement and concrete. It was observed that damage to the steel structural framework in the second structure (a prefabricated concrete–steel hybrid) triggered damage in the prefabricated concrete system. The precautions that need to be taken in terms of fire, especially in industrial structures, were evaluated based on either the load-carrying system or the section, and suggestions for improvements are made.

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This study investigates the availability of Genetic Programming (GP) for modeling the ultimate shear capacity of composite beams with profiled steel sheeting for the first time in literature. Experimental data involving push-out test specimens of 46 composite beams from an existing database in the literature were used to develop GP model. The input parameters affecting the shear capacity were selected as stud position (strong and weak), sheeting type (width of rib of the profiled steel sheeting, depth of the rib), stud dimensions (height and diameter), slab dimensions (width, depth and height), reinforcement in the slab and concrete compression strength. Moreover, a short review of well-known building codes regarding ultimate shear capacity of composite beams is presented. The accuracy of the codes in predicting the ultimate shear capacity of composite beams was also compared with the proposed GP model with comparable way by using same test data. The study concludes that the proposed GP model predicts the ultimate shear capacity of composite beams by far more accurate than building codes.Keywords: Shear connection, composite beams, push-out tests, genetic programming INTRODUCTIONThe composite behavior of two or more structural members joined together by using different materials is called "a composite structure". Each material of a composite structure usually has a superior property effectively used for providing the composite behavior of the materials. Although several materials are used as the shear connector of a composite structure, "headed stud" shear connectors are generally used in constructions due to their practicality.In the composite beams with profiled steel sheeting many factors such as; dimensions and direction of profiled steel sheeting, compressive strength of concrete, reinforcement area and position and also strength, dimension and location of shear connectors affect the behavior of shear connectors. Push out tests is commonly used to determine the capacity of the shear connectors and load-slip behavior of shear connectors. According to Eurocode 4 [1], the push-out specimens consist of a steel beam section held in the vertical position by two identical concrete slabs. The concrete slabs are attached to the beam by shear connectors. The connection is subjected to a vertical load, which produces a shear load along the interface between the concrete slab and the beam flange on both sides. At a specified load or displacement the slip between the slabs and the beam flange is evaluated. The failure load divided by the numbers of the connectors is assumed as the shear connection capacity [2].Composite construction using steel and concrete has been used since the early 1920s. It gained widespread use in bridges in the 1950s and in buildings in the 1960s [3]. Both push-out tests, which were first used in Switzerland in the 1930s [4], and full-scale beam tests have been used to develop shear stud strength prediction expressions. Push-out tests are usually used to evaluate a wide array of parame...

This study examines the damage caused to reinforced concrete structures by the 2011 earthquake that occurred in Simav, Turkey. The study briefly reports on post-earthquake field observations, tectonic characteristics of the earthquake area, geotechnical characteristics of the field, and seismic characteristics of the earthquake. The main part of the study comprises a field study, material experiments, and performance analyses of two reinforced concrete buildings that survived the earthquake with medium level damage. The building performance was calculated and assessed according to the Turkish Earthquake Code requirements for existing building stock, and recommendations were made based on the findings

The objective of this study was to make an experimental investigation on the behavior of nine steel frames with various infill characteristics under reverse cyclic loading. The test specimens, which were one-story steel frames, had the frame length/height ratios (l/h) of 1, ½, and 2. The infill characteristics of the specimens were assigned as i) no infill, ii) brick wall infill, iii) brick wall+plaster infill. The specimens were tested under reverse cyclic loading representing the seismic loading in the horizontal direction, and the displacement values obtained during the tests were measured and recorded in a digital manner. At the end of the tests, the infilled frames were evaluated in terms of failure types, strength envelopes, energy consumption characteristics, and stiffness decreases by comparing the test results.