1,721,007 research outputs found
Seismic solution based on the use of cross-laminated timber (clt) panels with sliding joints as infilled earthquake bracing system for rc framed architectures
Full text linkCross Laminated Timber (CLT) has gaining more and more attention in the research and professional field as a sustainable and promising construction system for mid- and high-rise structures. The need of buildings higher than that usually built with CLT has pushed the research towards the development of innovative hybrid techniques in which steel framed structures incorporate CLT shear walls. This concept may be potentially extended to existing RC framed buildings where infilled CLT shear walls may constitute the base for an integrated seismic and energy retrofit solution. In order to investigate this potentiality, this paper present a preliminary experimental study focused on the diagonal strut behaviour of CLT panels. In particular, diagonal compression tests on 3-ply panels have been carried out also by simulating the confinement effect provided by the structural frame. A comparison with the results of similar tests on CLT panels with different number of layers and thickness has been also provided. The results of this research have demonstrated that CLT panels has a higher strength and stiffness if confined. Then, the confinement effect provided by the RC frame on the infill should be accurately considered in the strengthening design
SHEAR AND THERMO-HYGROMETRIC PERFORMANCE OF STRUCTURAL INSULATED PANELS COMPRISING EPS CORE AND OSB SKINS
No full textIn the last decades, the need for improved thermal-structural integrated solutions for building construction has prompt towards the development of Structural Insulated Panels (SIPs), a cost-effective wall system capable of transferring shear loads among panel layers and minimizing localized heat loss This study explored both mechanical and thermal behaviour of SIPs, composed by an Expanded Polystyrene (EPS) core within two oriented strand board (OSB) sheets. Six panels (1200x1200x170mm3) were tested under in-plane horizontal load in two configurations: (i) three single SIP wall; (ii) three double SIPs wall, joined together with a block spline and metal connections. Both specimens were anchored to a lower steel metal beam through anchor bolts and hold-downs. Moreover, the panels were characterized as regard the steady-state thermal behaviour. The study demonstrated that this wall system is a viable solution for sustainable buildings since it presents high shear strength, elevated ductility and good thermal-hygrometric performance
The role of areal heat capacity and decrement factor in case of hyper insulated buildings: An experimental study
No full textMechanically ventilated classrooms in central Italy's heritage school buildings: Proposal of archetypes and CO2 prediction models
No full textThis study proposed a typological analysis to identify the archetypes of classrooms equipped with controlled mechanical ventilation (CMV) in Italy and an experimental campaign on 58 typical classrooms to identify the main indoor microclimatic characteristics and CO2 concentrations. From the analyses carried out, general information was gathered on the heating systems and the main energy and acoustic improvements carried out in the schools. The typological analysis identified four different types of mechanical ventilation systems installed in three different classroom archetypes: wide, square and deep, with percentages of window area of 25%, 30% and 40 % respectively. The field measurement campaign showed that, in terms of CO2 concentration, mechanical ventilation was effective in the winter period, while in the mid-season and summer periods, natural ventilation was predominant due to the opening of windows by the occupants. Furthermore, in the case of manual control, incorrect use of the machine by the occupants, who reported noise-related problems or insufficient user training, resulted in CO2 levels above the recommended limits. Multivariate regressions developed for schools equipped with CMVs predicted maximum and average CO2 concentrations as a function of minimum and maximum indoor and outdoor temperatures with a significance (R2, correct) of 76 % and 83 % respectively
Data-driven automation of HVAC systems: An experimental study in a university study room
No full textThis study proposes a framework for controlling HVAC systems for university study rooms that includes a data-driven model capable of identifying the probability of user interaction with air conditioning and ventilation systems, depending on the thermal sensation vote (TSV), perceived air quality (PAQ) and microclimate parameters (air and operative temperature, air velocity, relative humidity and CO2). The experimental setup allowed the participants to carry out their usual study/work activities without the need to be supervised. This allowed the occupants not to be psychologically conditioned and made their experience and interaction with the environment/systems as realistic as possible. The analysis of the experimental data showed that the operative temperature mainly influences the thermal sensation of the occupant inside the room, while the perceived air quality depends not only on the CO2 concentration but also on thermal perception and air velocity. Furthermore, three predictive models (heating, cooling and IAQ) were obtained from the experimental data, indicating the probability of user interaction with the system (R2 between 0.85 and 0.94). The heating phase model was also verified by automatizing the heating system through the developed framework and comparing the user's sensations before and after control (users unaware of the changes). The use of the models increased users' thermal comfort from 39 % to 82 %, confirming the effectiveness of the syste
Statistical Experimental Design-Driven Discovery of Room Temperature Conditions for Palladium - Catalyzed Cyanation of Aryl Bromides
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An experimental and numerical study on CLT panels used as infill shear walls for RC buildings retrofit
Full text linkCross Laminated Timber (CLT) has been gaining more and more attention in research and professional fields as a sustainable and promising construction system for mid- and high-rise structures. The need of buildings higher than those usually built with CLT has pushed the research towards the development of innovative hybrid techniques in which steel framed structures incorporate CLT shear walls. This concept may be potentially extended to existing RC framed buildings, where CLT infill shear walls may constitute the base of an integrated seismic and energy retrofit. In order to investigate this potentiality, this paper presents a preliminary experimental and numerical study focused on the mechanical behavior of CLT panels used as a bracing system. In particular, diagonal compression tests on 3-ply panels have been carried out, also by reproducing a direct load transmission from the RC frame to the CLT infill. A comparison with the results of similar tests on CLT panels (with a different number of layers and thickness) and with unstrengthened and strengthened masonry infill walls has been also provided. In addition, numerical simulations have been carried out, in order to evaluate the changes in RC frame lateral response when CLT infills are added. The results have proved that CLT infills may be used as a strengthening solution, allowing RC frame to reach higher lateral stiffness and peak load values respect to masonry infills
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