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The assessment of the dynamic properties and vibration performance of two full-scale timber floor specimens is presented. The specimen set comprised a Timber-Concrete Composite floor and a Cross Laminated Timber floor. The floors, which are characterized by the same length and mass, are located in two separate five-storey timber buildings constructed in the urban area of Trento (Italy). The assessment was conducted by adopting analytical and numerical methods as well as by performing onsite experimental tests. Mock up samples of the floor specimens were also made and tested in laboratory. Multiple analytical methods that are available in literature were evaluated and compared. The Vibration Dose Value (VDV) method, as proposed by ISO 10137 and BS 6472, was used as reference method for the numerical modelling and the laboratory testing. To determine the VDV, loading associated to human walking was simulated. Dynamic identification tests, where the floors were excited by a modal hammer, were also performed in order to investigate the dynamic properties (i.e. natural frequencies, damping and mode shapes) of the floors. Discussion on the vibration performance of the timber floor typologies studied herein and on the effectiveness of the different assessment approaches (i.e. analytical, numerical and experimental) is provided.

This paper discusses a seismic retrofit method that is intended for reinforced concrete (RC) frame structures and that sees the replacement of the existing masonry infills with timber structural panels. The intervention is aimed at enhancing the overall behaviour of the buildings without modifying the original concrete structural system. In the presented research over 200 finite-element models comprising bare, masonry-infilled and retrofitted single-storey single-bay frames were subjected to nonlinear static analyses. The response of the timber-infilled frames was then optimised, thus enabling the definition of a few simple design rules to guide the implementation of the retrofit system. Subsequently, the efficacy of the proposed solution was further investigated by applying the timber-based retrofit to an entire case-study building modelled via finite elements and subjected to nonlinear static pushover analysis. The comparison of the results obtained for the building in the original and retrofitted configurations indicates that the proposed system can favour the development of ductile behaviours and improve the seismic response of RC frame structures significantly.

The experimental out-of-plane performance of timber-to-timber composite floor structures was experimentally investigated. Specifically, 6-point bending tests were performed on seventeen full-scale floor specimens (6.4 m span) assembled with inclined screw fasteners (both single threaded and double threaded screws) and by using combinations of different timber products (e.g. spruce cross laminated panels, beech laminated veneer lumber beams/panels). For most of the specimens, a cambering and pre-stressing technique (CP procedure) was utilised by exploiting the compression force produced by screw fasteners. The experimental observations indicated that it is possible to obtain camber values that go from approximately 1/900 to 1/250 of the floor span, according to the design needs. As an indicator of the wide possible range of pre-stress forces, the vertical force required to eliminate the camber was monitored during testing, resulting in measured values ranging from 2.4 kN/m2 to 13.8 kN/m2 (0.6 m joist spacing). The applicability of the proposed solutions in real design scenarios was evaluated by comparing the experimental results with the predictions obtained by using a proposed analytical approach. A good correlation was observed between the test data and the theoretical predictions.