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- Numerical model to assess the fire behaviour of cellular wood slabs with drillingsPublication . Fonseca, E.M.M.; Barreira, Luísa; Meireles, J.M.; Piloto, P.A.G.The main goal of this paper is to develop a numerical model to assess the fire behaviour of cellular wood slabs with different drillings. A transient thermal analysis with nonlinear material behaviour will be solved with ANSYS program. The presented numerical model is based on a constructive solution proposed by Frangi and Fontana. The numerical results obtained will be compared with the experimental results from the reference. The developed numerical model allows future studies and simultaneously characterizes the effect of perforations in wooden slabs to minimize the fire risk. The numerical model can easily be adjusted for other constructive solutions, to facilitate the verification of safety in case of fire, in buildings with several wood floors and slabs assemblies.
- Fire resistance of cellular wooden slabs with rectangular and circular perforationsPublication . Couto, David; Fonseca, E.M.M.; Piloto, P.A.G.; Meireles, J.M.; Barreira, Luísa; Ferreira, DéboraThis work presents a numerical and experimental approach in order to predict the thermal behaviour and the performance of typical cellular wooden slabs with rectangular and circular perforations when submitted to fire conditions. For this purpose a 3D numerical model was validated with different experimental tests at real scale obtained in laboratory in four cellular wooden slabs. This study was conducted in accordance with European standard (EN 1365-2, 1999) and using a fire resistance furnace which complies the requirements of European standard (EN 1363-1, 1999). The numerical temperatures show good agreement with experimental results. The numerical model can easily be adjusted for other constructive solutions, to facilitate fire safety tests, in buildings with wooden slabs used in floors or in ceilings applications.
- Fire behaviour of lightweight concrete units based on corn cob aggregatePublication . Nuno, Alves; Piloto, P.A.G.; Fonseca, E.M.M.; Barreira, Luísa; Ferreira, Débora; Pinto, JorgeRecent research works have concluded that corn cob may have interesting material properties, in particular, lightness, and thermal and sound insulation abilities. In this research work, corn cob is proposed as an alternative sustainable aggregate for lightweight concrete masonry unit (CMU) manufacturing. The corn cob requires to be granulated previously in order to obtain adequate particle size grade. Subsequently, the particles are wrapped in a cement paste with the purpose of reducing their water abortion and adherent capacities. CMU are current applied in the building of partition walls. The main goal of this research work consists on studying the fire behaviour of partition walls built with CMU of processed corn cob granulate (CMU-PCC).
- Numerical model to assess the fire behaviour of cellular wood slabs with drillingsPublication . Fonseca, E.M.M.; Barreira, Luísa; Meireles, J.M.; Piloto, P.A.G.The main goal of this paper is to develop a numerical model to assess the fire behaviour of cellular wood slabs with different drillings. A transient thermal analysis with nonlinear material behaviour will be solved with ANSYS program. The presented numerical model is based on a constructive solution proposed by Frangi and Fontana. The numerical results obtained will be compared with the experimental results from the reference. The developed numerical model allows future studies and simultaneously characterizes the effect of perforations in wooden slabs to minimize the fire risk. The numerical model can easily be adjusted for other constructive solutions, to facilitate the verification of fire safety, in buildings with several wood floors and slabs assemblies.
- Perforated cellular wooden slabs under fire: Numerical and experimental approachesPublication . Couto, David; Fonseca, E.M.M.; Piloto, P.A.G.; Meireles, J.M.; Barreira, Luísa; Ferreira, DéboraThis work presents a numerical and experimental approach in order to predict the fire resistance of perforated cellular wooden slabs. The wooden slabs are lightweight, easy installation, excellent architectural, thermal and acoustic characteristics. However, its high vulnerability to fire, requires their behaviour assessed accurately. Wood material produces a surrounding char layer in depth, when exposed to fire resulting in a reduced residual section. For this purpose, different cellular wooden slabs, with the bottom surface perforated, including different small and large rectangles and circles, were tested and submitted to fire exposure. The experimental study was conducted in laboratory in accordance with European standard (EN1365-2, 2012), using a fire resistance furnace which complies the requirements of European standard (EN1363-1, 2012). Also a three-dimensional thermal and transient numerical model, using a finite element program Ansys®, was validated with experimental tests at real scale. The numerical and experimental results show good agreement. The numerical model can easily be adjusted for other constructive solutions, in order to facilitate fire safety tests, in buildings with wooden slabs used in floors or in ceilings applications.
- Fire resistance of cellular wooden slabs with rectangular and circular perforationsPublication . Couto, David; Fonseca, E.M.M.; Piloto, P.A.G.; Meireles, J.M.; Barreira, Luísa; Ferreira, DéboraThis work presents a numerical approach in arder to predict the behaviour and the perfonnance of typical cellular wooden slabs with rectangular and circular perforations when submitted to fire conditions. For this purpose a 3D numerical model was validated with different experimental tests at real scale obtained in laboratory m four cellular wooden slabs. This study was conducted in accordance with European standard EN 1365-2 and using a fire resistance íümace which complies the requirements ofEN 1363-1. The thermal perfomiance of the slab and the charring rate of the exposed siiïface will be compared for each type of perforations.
- Structural safety in wooden beams under thermal and mechanical loading conditionsPublication . Fonseca, E.M.M.; Coelho, Diana C.S.; Barreira, LuísaThe main objective of this paper is to identify different analytical methods which permit the calculation of the stress level in wooden simply supported beams, due to mechanical and thermal loading conditions. Two different wood species, with different cross-sections, will be presented. The fi reresistance, the charring depth layer and the charring rate will be determined using the fi nite element method with Ansys® program. To characterize the stress state in wooden beams, all elements are subjected to mechanical load considering the reduction of the cross-section, infl uenced by thermal action. Another purpose of this work is to identify the ultimate safe load-bearing capacity in wooden beams, subjected to uniform load simultaneously with the thermal effect. All numerical results permit the specifi cation of simple design calculation methods, simplifying the verifi cation of the fi re safety of wooden beams.
- Fire behaviour of lightweight concrete units based on corn cob aggregatePublication . Alves, Nuno; Piloto, P.A.G.; Fonseca, E.M.M.; Barreira, Luísa; Ferreira, Débora; Pinto, JorgeThe search for alternative environmental friendly building solutions has been the goal of the scientific and the technical communities. Affordable, low energy and good quality water consumptions, and small amount of CO2 emission into the atmosphere are important attributes that these solutions have to fulfil. In general, applying organic products as raw building materials may be a step forward to achieve these attributes because they are likely of being abundant, local and renewable. For instance, rice husk ash blended cement has been proposed as a partial substitute of cement in mortar production.(...)