1. Cyclic response of insulated steel angle brackets used for cross-laminated timber connectionsMeta Kržan, Boris Azinović, 2021, izvirni znanstveni članek Povzetek: In cross-laminated timber (CLT) buildings, in order to reduce the disturbing transmission of sound over the flanking parts, special insulation layers are used between the CLT walls and slabs, together with insulated angle-bracket connections. How-ever, the influence of such CLT connections and insulation layers on the seismic resistance of CLT structures has not yet been studied. In this paper, experimental investigation on CLT panels installed on insulation bedding and fastened to the CLT floor using an innovative, insulated, steel angle bracket, are presented. The novelty of the investigated angle-bracket connection is, in addition to the sound insulation, its resistance to both shear as well as uplift forces as it is intended to be used instead of traditional angle brackets and hold-down connections to simplify the construction. Therefore, monotonic and cyclic tests on the CLT wall-to-floor connections were performed in shear and tensile/compressive load direction. Specimens with and without insulation under the angle bracket and between the CLT panels were studied and compared. Tests of insulated specimens have proved that the insulation has a marginal influence on the load-bearing capacity; however, it significantly influences the stiffness characteristics. In general, the experiments have shown that the connection could also be used for seismic resistant CLT structures, although some minor improvements should be made.
Ključne besede: CLT connection, equivalent viscous damping, experimental shear tests, polyurethane sound-insulation, steel angle bracket
Objavljeno v DiRROS: 19.07.2023; Ogledov: 298; Prenosov: 127
 Celotno besedilo (2,57 MB)
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2. Improved seismic response of light-frame-timber panels with cement-particle-board sheathing of various thicknesses and different configurations of fastenersMeta Kržan, Tomaž Pazlar, Boštjan Ber, 2022, izvirni znanstveni članek Povzetek: Due to their comparable fire characteristics and surface preparation, light-frame timber panels using cement-particle boards (CPB) as a sheathing material present a potential alternative to gypsum-fibre boards. An experimental campaign was conducted to evaluate the behaviour of CPB light-frame-timber panels under in-plane lateral loading. Monotonic and cyclic in-plane shear tests were conducted on full-size panels, following preceding tests on the stapled sheathing-to-timber connections used in the panels. The influence of the boards’ thickness and staple geometry on the response of connections and panels was studied, also on panels with an asymmetrical CPB layout, which proved not to have a negative influence on the panels’ lateral load-bearing capacity. Furthermore, in order to improve the seismic response, panels, which had almost twice the number of staples compared to the basic panel, were tested; one variation with two rows of staples, and the other with the staples spaced closer together, such that the spacing distance was halved. The tests revealed a significant, though not proportional, increase in lateral resistance in the strengthened panels. Fastening the CPB with two rows of staples proved the better option, since subsequent failure of the CPB along the connections, as opposed to ductile failure of the staples in the basic panels, proved not to reduce the panels’ deformation capacity. The paper also compares the test results of the connections and panels to analytical results according to Eurocode 5 (EC5), the European code provision for the design of timber structures.
Ključne besede: light-frame timber panels, cement-particle board sheathing, cyclic shear tests, sheathing-to-timber connection, asymmetrical panel, staple spacing distance, EN 1995–1-1, open access
Objavljeno v DiRROS: 31.05.2023; Ogledov: 410; Prenosov: 195
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3. In-plane seismic behaviour of ashlar three-leaf stone masonry walls : verifying performance limitsMeta Kržan, Vlatko Bosiljkov, 2021, izvirni znanstveni članek Povzetek: In light of the forthcoming second generation Eurocodes (EC), the results of conducted systematic in-plane cyclic and compressive tests on three-leaf stone masonry walls are discussed following new requirements and provisions. The new proposal for EC8-3 for existing buildings is based on partial factors safety approach, though it considers different uncertainties in defining input parameters for effective seismic performance-based assessment. Prior to its application, massive calibration effort will be needed since there is no standardized method for shear testing of masonry walls. In this paper, the performance limit states damage, resistance, and displacement capacities from conducted test results were evaluated and assessed through comparison with analytical solutions and imposed limit values, as stated in existing codes. The test results provide a much higher deformation capacity than the limits provided in both existing and new proposal of EC8-3 as well as those in the ASCE code provisions. The reason for this lies in the soft, "ductile" mortar for which the presumed resistance according to code provisions should be significantly higher when considering good quality ashlar three-leaf stone masonry.
Ključne besede: historical masonry, multi-leaf stone masonry, mechanical properties, compression tests, in-plane shear tests, failure mechanisms, drift limits, boundary conditions
Objavljeno v DiRROS: 19.05.2023; Ogledov: 323; Prenosov: 165
Celotno besedilo (4,47 MB)
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