The paper reports the results of a comprehensive experimental test performed on a 6 m span timber-concrete composite beam with glued re-bar connection. The beam had first been subjected to sustained load in unsheltered outdoor conditions for 5 years. Eventually a ramp loading test up to failure was performed. The long-term test showed an increase in deflection mainly during the first two years, while the slip rose during the whole testing period. Thermohygrometric variations of environment caused an important fluctuation of all quantities on both yearly and daily scale. By comparing experimental and analytical results, it is highlighted that composite beams in outdoor conditions should be assigned to the 3rd service class according to the Eurocode 5 (EC5). Analytical predictions based on approximate formulae suggested by such regulation are found to be not conservative for the long-term behaviour and fairly accurate for the collapse behaviour. Since the simplified formulae proposed by the latest versions of the EC5-Parts 1.1 and 2 largely underestimate the actual connection stiffness and strength, it is recommended that realistic values of these properties, such as those obtained through push-out tests, be used when designing timber-concrete composite beams
The key role of beam-column joints in the seismic response of moment resisting frames (MRF) has been fully recognized. In the performance-based seismic design of steel storage pallet racks, many researches have highlighted the need to take into account the inelastic response of beam-column joints. Pallet racks are characterized by boltless beam-column connections and the extensive use of thin-walled cold-formed steel members. Due to the great number of beam-end connector types and member geometries, specific tests are required to evaluate the structural behavior of these structures. In particular, their seismic analysis requires a thorough modeling of the behavior of beam-column joints, which has been investigated by the authors through experimental tests under monotonic and cyclic loads. Tested connectors have exhibited different values of the bending stiffness and the ultimate bending moment, depending on structural details of each joint's type, like the number of tabs. Cyclic tests have shown a pinching in the hysteresis curve, underlining that the cyclic response of tested joints is significantly different from joints of traditional steel framed buildings. Experimental results confirmed the importance of cyclic tests on beam-end connectors to correctly identify their moment-rotation curve, which is required to perform reliable seismic analyses of steel pallet racks.
The chapter reports on the in-situ experimental campaign and the numerical modelling that were performed to assess the static and dynamic behaviour of the Cupola of the Siena Cathedral in Italy: an irregular polygonal masonry structure built in the 13th century and composed of two domes. The research was motivated by the failure of some of the stone-trusses which connect the two masonry domes and consists of: a) single and double flat-jack tests in the internal dome, b) dynamic vibration tests on the Cupola under environmental (wind) and artificial (vibrodyne) loads and c) dynamic vibration tests on the double colonnade located below the Cupola (hammer impact tests). Results of tests were employed to identify a numerical model of the Cupola, which allowed to simulate its structural behaviour and to account for the failure of the stone-trusses between the two domes. The numerical model was later extended to the whole Cathedral. Through the discussion of an emblematic case study, the chapter shows a careful application of non-destructive testing (NDT) and numerical modelling in the field of assessment (and rehabilitation) of heritage buildings.
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