The application of steel joists to floor construction can be traced back more than 100 years to the use of a sheet steel joist in the State of New York Bank Building in 1855. Since that time various forms of joists have been developed and exploited. As a result, two general types of joists are now on the market: a) Solid web joists; b) Open web, or truss type, steel joists. In order to determine the strength, stiffness, and behavior of these structural sections under load, representative open web steel joists have been tested at the University of Miami, School of Nursing Building (building about to be demolished). Using two hydraulic jacks to apply the load at eight different locations along the strip, the assessment of the ultimate structural performance of the floor system to positive moments in correspondence of selected strips was possible. After analyzing the data collected from the sensors through the data acquisition system, it was concluded that the results obtained from the Finite Element model were consistent compared to the results obtained from the experimental approach, helping to understand better the behavior of this structural system. A recommendation for further study is enclosed.

This thesis summarizes the results of an experimental investigation involving the testing of push-out specimens with channel shear connectors. The test program involved the testing of 78 push-out specimens and was aimed at the development of new equations for channel shear connectors embedded in solid concrete slabs and slabs with wide ribbed metal deck oriented parallel to the beam. <p>The test specimens were designed to study the effect of a number of parameters on the shear capacity of channel shear connectors. Six series of push-out specimens were tested in two phases. The primary difference between the two phases was the height of the channel connector. Other test parameters included the compressive strength of concrete, the length and the web thickness of the channel. <p>Three different types of failure mechanisms were observed. In specimens with higher strength concrete, failure was caused by the fracture of the channel near the fillet with the channel web acting like a cantilever beam. Crushing-splitting of concrete was the observed mode of failure in specimens with solid slabs when lower strength concrete was used. In most of the specimens with metal deck slabs, a concrete shear plane type of failure was observed. In the specimens involving this type of failure, the channel connector remained intact and the concrete contained within the flute in front of channel web sheared off along the interface. <p>The load carrying capacity of a channel connector increased almost linearly with the increase in channel length. On average, the increase was about 39% when the channel length was increased from 50 mm to 100 mm. There was a further increase of 24% when the channel length was increased from 100 mm to 150 mm. The influence of web thickness of channel connector was significant when the failure occurred due to channel web fracture but was minimal for a concrete crushing-splitting type of failure. <p>The specimens with solid concrete slabs carried higher load compared to those with metal deck slabs. The increase in load capacity was 33% for specimens with 150 mm long channels but only 12% for those with 50 mm long channel connectors. <p>This investigation resulted in the development of a new equation for predicting the shear strength of channel connectors embedded in solid concrete slabs. The proposed equation provides much better correlation to test results than those obtained using the current CSA equation. <p>The results of specimens with metal deck slabs were used to develop a new equation for predicting the shear capacity of channel connectors embedded in slabs with metal deck oriented parallel to the beam. The values predicted by the proposed equation were in good agreement with the observed test values.

This thesis summarizes the results of an experimental investigation involving the testing of push-out specimens with channel shear connectors. The test program involved the testing of 78 push-out specimens and was aimed at the development of new equations for channel shear connectors embedded in solid concrete slabs and slabs with wide ribbed metal deck oriented parallel to the beam. <p>The test specimens were designed to study the effect of a number of parameters on the shear capacity of channel shear connectors. Six series of push-out specimens were tested in two phases. The primary difference between the two phases was the height of the channel connector. Other test parameters included the compressive strength of concrete, the length and the web thickness of the channel. <p>Three different types of failure mechanisms were observed. In specimens with higher strength concrete, failure was caused by the fracture of the channel near the fillet with the channel web acting like a cantilever beam. Crushing-splitting of concrete was the observed mode of failure in specimens with solid slabs when lower strength concrete was used. In most of the specimens with metal deck slabs, a concrete shear plane type of failure was observed. In the specimens involving this type of failure, the channel connector remained intact and the concrete contained within the flute in front of channel web sheared off along the interface. <p>The load carrying capacity of a channel connector increased almost linearly with the increase in channel length. On average, the increase was about 39% when the channel length was increased from 50 mm to 100 mm. There was a further increase of 24% when the channel length was increased from 100 mm to 150 mm. The influence of web thickness of channel connector was significant when the failure occurred due to channel web fracture but was minimal for a concrete crushing-splitting type of failure. <p>The specimens with solid concrete slabs carried higher load compared to those with metal deck slabs. The increase in load capacity was 33% for specimens with 150 mm long channels but only 12% for those with 50 mm long channel connectors. <p>This investigation resulted in the development of a new equation for predicting the shear strength of channel connectors embedded in solid concrete slabs. The proposed equation provides much better correlation to test results than those obtained using the current CSA equation. <p>The results of specimens with metal deck slabs were used to develop a new equation for predicting the shear capacity of channel connectors embedded in slabs with metal deck oriented parallel to the beam. The values predicted by the proposed equation were in good agreement with the observed test values.

Progressive collapse research aims to characterize and quantify the behavior of different structural systems in events of extreme local damage caused by bombings to improve the performance of targeted structures and to protect occupants. The focus of the research program described herein is the performance of steel gravity frame structures with composite floor systems in column loss scenarios. The goal of the project is to contribute to the development of rational design guidelines for progressive collapse resistance and to assess any potential weaknesses in current design standards. This thesis presents the results of a series of tests performed on a steel frame structure with simple framing connections and a composite floor slab under interior column loss. The specimen was designed and constructed in accordance with typical design practices and was subjected to increasing uniform floor loads after static removal of the central column. No significant structural damage was observed up to a load equivalent to the ultimate gravity design load. Further testing was performed after the deliberate reduction of the capacity of the steel framing connections, ultimately resulting in total collapse of the specimen. / text

No / Circular economy is an economic system aimed at minimizing wastes and making the most of the current resources. This regenerative approach contrasts with the traditional linear economy, which has been adopted by the construction industry. Developing new construction technologies for sustainable built environment is a top priority for the construction industry throughout the world. Much of the environmental impact from the construction industry is associated with the consumption of resources and generation of waste. The construction industry in Europe consumes over 70,000 million tonnes of materials each year and generates over 250 million tonnes of waste. Composite flooring formed by connecting the concrete slabs to the supporting steel beams has been widely used for many years and is well established as one of the most efficient floor systems in multi storey steel frame building structures. However, shear connectors are welded through the steel decking to the steel beams and cast into the concrete; this made deconstruction and reuse of these components almost impossible. A new composite flooring system which allows for the reuse of the steel beams and composite floor slabs is developed and tested to assess its potential and suitability for reuse. This paper presents the results of a series of full scale beam tests and demonstrates the reusability of this new form of composite flooring systems. Simplified hand calculations are also provided and compared against beam tests / EPSRC, Structural Metal Deck Ltd.