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14th International Conference on Non-Conventional Materials and Technologies for Sustainable engineering, NOCMAT 2013

作者： Lima, Paulo Roberto Lopes Filho, Romildo Dias Toledo Da Fonseca Martins Gomes, Otávio 1Post-graduate Program of Civil and Environmental Engineering Department of Technology State University of Feira de Santana Av. Transnordestina S/N-Novo Horizonte Feira de Santana Bahia 44036-900 Brazil Civil Engineering Program/COPPE Federal University of Rio de Janeiro Rio de Janeiro Brazil Centre for Mineral Technology-CETEM Av. Pedro Calmon 900 21941-908 Rio de Janeiro Brazil University of Liege GeMMe Georesources and Geoimaging Sart Tilman B52 4000 Liege Belgium

ISBN: (纸本)9783037859810

In this work it was studied the influence of recycled fine aggregate obtained from construction and demolition waste (CDW) on the rheological properties of Portland cement mortars. The CDW was initially separate in their main constituents (mortar, ceramic and concrete debris) at the laboratory and then grinded separately to the sand size in order to generate more homogeneous fine aggregates. The characterization of the natural and recycled sands was carried out through physical tests, X-ray diffraction, scanning electron microscopy (SEM), and image analysis (shape and texture description parameters). A conventional mortar and three mortars containing recycled sands were produced with a sand/cement ratio of 4 and consistency index of 255±5 mm. The consistency was kept constant by ranging the water-cement ratio from 0.58 to 1.14. The rheological study was performed using a rotating viscometer to obtain torque-rotation ratio and to calculate the yield stress and plastic viscosity. The results indicate that the presence of recycled aggregate causes a lowering of both yield stress and plastic viscosity with respect to the mortar containing natural aggregate. © (2014) Trans Tech Publications, Switzerland.

关键词： Mortar

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A feasibility study of recycling of construction and demolition waste for structural purposes

Journal of Solid Waste Technology and Management

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Journal of Solid Waste Technology and Management 2013年第3期39卷 204-213页

作者： Mariano, Leila Seleme Da Costa, Marienne Do Rocio De Mello Maron Braga, Maria Cristina Borba Brasilian Air Force Integrated Air Traffic and Control Center - CINDACTA II Brazil Parana Federal University Department of Civil Engineering Civil Engineering Post-Graduate Program Brazil Parana Federal University Department of Hydraulics and Sanitation Water Resources and Environmental Engineering Post-Graduate Program Brazil Universidade Federal do Paraná Setor de Tecnologia Centro Politécnico - Jardim das Américas CxP 19011 81531-980 Curitiba - Paraná Brazil

The environmental problems related to construction and demolition waste involve their final dis-posal and the use of raw materials. The main goal of this research was to manage on site con-struction and demolition waste and generate concrete for structural purposes by processing concrete and mortar wastes. A Construction and Demolition Waste Management Plan (CDWMP) was developed for this study and applied by means of the implementation of recy-cling procedures. This plan included quantifying wastes and analyzing their generation. The concrete and mortar wastes were separated for recycling to produce concrete in which these wastes, respectively, replaced fractions of coarse aggregate (crushed stone) and fine aggre-gate (sand). Tests were carried out to characterize the resulting concrete and the aggregates used. The strength of the concrete generated varied from 6 MPa to 21.4 MPa, for the same mixture. It was observed that structural concretes can be produced using recycled aggregates, however this cost is higher compared to that of concrete produced with conventional aggre-gates. It was also concluded that despite the cost of concrete production, there were environmental and economic advantages to performing and applying the CDWMP to this specific con-struction site. Copyright © 2013 Widener University.

关键词： Recycling

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Dynamic analysis of steel-concrete composite tubular footbridges submitted to human walking

Dynamic analysis of steel-concrete composite tubular footbri...

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4th International Conference on Computational Methods in Structural Dynamics and Earthquake engineering, COMPDYN 2013

作者： Debona, Gilvan L. Da Silva, José G. S. Sieira, Ana C. C. F. Civil Engineering Post-graduate Programme PGECIV State University of Rio de Janeiro UERJ São Francisco Xavier St. 524 Maracanã 20550-900 Rio de Janeiro RJ Brazil Structural Engineering Department ESTR State University of Rio de Janeiro UERJ São Francisco Xavier St. 524 Maracanã 20550-900 Rio de Janeiro RJ Brazil

ISBN: (纸本)9789609999427

The increasing incidence of footbridges excessive vibration problems due to human walking induced loads led to an increase in the number of complaints arising from annoying human-induced vibrations in new footbridge structures. Based on the improvements in design methods, structural engineers seem to continuously move the safety border to increase slenderness and lightness of their footbridges using more slender structural designs. Considering all aspects mentioned before, this was the main motivation for the development of a finite element modelling of the dynamic behaviour of steel-concrete composite tubular footbridges, when subjected to human walking vibrations. The investigated structural system was based on a steel-concrete composite tubular footbridge spanning 82.5 m. The structural model consists of tubular steel sections and a concrete slab. This investigation is carried out based on correlations between the experimental results related to the footbridge dynamic response and those obtained with finite element modelling. The finite element model enabled a complete dynamic evaluation of the composite tubular footbridge in terms of human comfort and its associated vibration serviceability limit states. The peak accelerations found in the present analysis indicated that the investigated footbridge presented problems related with human comfort. Hence it was detected that this type of structure can reach high vibration levels that can compromise the footbridge user's comfort.

关键词： Structural dynamics

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GIS as a Decision Support Tool in the Area of Influence of the Nuclear Complex Angra dos Reis, Brazil

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Journal of Geographic Information System 2013年第1期5卷 13-23页

作者： Corbiniano Silva Luiz Landau Luiz Claudio Gomes Pimentel Paulo Fernando Lavalle Heilbron Filho Civil Engineering Program Alberto Luiz Coimbra Institute of Post Graduate Studies and Research Federal University of Rio de Janeiro Rio de Janeiro Brazil Mechanical Engineering Program Alberto Luiz Coimbra Institute of Post Graduate Studies and Research Federal University of Rio de Janeiro Rio de Janeiro Brazil National Commission for Nuclear Energy Rio de Janeiro Brazil

The outlook concerning the occurrence of industrial accidents has led to the implementation of response systems based on geoprocessing tools, which are widely adopted in emergency for such ventures, since they have helped and served as a support for decision making, as well as for the preparation of guidelines aimed at managing emergencies. Nuclear power plants, because they constitute types of industrial activities that present dangerous conditions and attention regarding security are characterized as hazardous, especially due to consequences that occurred from large accidents— such as Chernobyl (1986) and Fukushima (2011)—highlighting the importance to its negative impacts, since the occurrence of accidents at nuclear power plants may affect surrounding areas, thus exposing a set of elements that are part of the environmental dynamics that integrates the catchment area where this type of plant is situated. In this way, through an integrated view of the region where the nuclear complex is located in Angra dos Reis City (Rio de Janeiro State) and, also, by aggregating information that portray the geobiophysical reality of its surroundings, several elements were incorporated into a database developed in a virtual environment, in which was produced a geographic information system (GIS) that presents a complex of variables that, once considered, can enhance various analysis in order to support emergency situations and planning, as well as guidelines that help define actions from the occurrence of accidental events at the nuclear plant.

关键词： Industrial Accidents Nuclear Power GIS Planning of Emergency Response Systems

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Finite element analysis of walking vibration problems for tubular steel-concrete composite footbridges

Finite element analysis of walking vibration problems for tu...

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11th International Conference on Computational Structures Technology, CST 2012

作者： Debona, G.L. Santos Da Silva, J.G. Sieira, A.C.C.F. Da S. Vellasco, P.C.G. De Lima, L.R.O. Civil Engineering Post-Graduate Programme PGECIV Brazil Structural Engineering Department UERJ State University Rio de Janeiro Brazil

ISBN: (纸本)9781905088546

The main objective of this investigation is to present the finite element modelling of the dynamic behaviour of tubular composite (steel-concrete) footbridges subjected to human walking vibrations. The investigated structural system was based on a tubular composite (steel-concrete) footbridge, spanning 82.5 m. The structural model consists of tubular steel sections and a concrete slab. This investigation is carried out based on correlations between the experimental results related to the footbridge dynamic response and those obtained with finite element modelling. The finite element model enabled a complete dynamic evaluation of the tubular footbridge in terms of human comfort and its associated vibration serviceability limit states. The peak accelerations found in the present analysis indicated that the investigated tubular footbridge presented problems related with human comfort. Hence it was detected that this type of structure can reach high vibration levels that can compromise the footbridge user's comfort. © civil-Comp Press, 2012.

关键词： Structural dynamics

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Vibration analysis of tubular footbridges induced by human walking

Vibration analysis of tubular footbridges induced by human w...

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14th International Symposium on Tubular Structures, ISTS 2012

作者： Debona, G.L. Da Silva, J.G.S. Sieira, A.C.C.F. Da S. Vellasco, P.C.G. De Lima, L.R.O. Civil Engineering Post-Graduate Programme PGECIV State University of Rio de Janeiro UERJ Rio de Janeiro Brazil

ISBN: (纸本)9780415621373

The main objective of this investigation is to present the finite element modelling of the dynamic behaviour of tubular composite (steel-concrete) footbridges submitted to human walking vibrations. The investigated structural system was based on a tubular composite (steel-concrete) footbridge, spanning 82.5 m. The structural model consists of tubular steel sections and a concrete slab. This investigation is carried out based on correlations between the experimental results related to the footbridge dynamic response and those obtained with finite element modelling. The finite element model enabled a complete dynamic evaluation of the tubular footbridge in terms of human comfort and its associated vibration serviceability limit states. The peak accelerations found in the present analysis indicated that the investigated tubular footbridge presented problems related with human comfort. Hence it was detected that this type of structure can reach high vibration levels that can compromise the footbridge user's comfort. © 2012 Taylor & Francis Group, London.

关键词： Concrete slabs

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Non-linear dynamic analysis of steel-concrete composite floors subjected to human rhythmic activities

Non-linear dynamic analysis of steel-concrete composite floo...

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11th International Conference on Computational Structures Technology, CST 2012

作者： Lopes, E.D.C. Gonçalves, S.G. Gaspar, C.M.R. Santos Da Silva, J.G. De Andrade, S.A.L. Civil Engineering Department Pontifical University Catholic of Rio de Janeiro PUC-Rio Brazil Civil Engineering Post-graduate Programme PGECIV Brazil Structural Engineering Department UERJ State University of Rio de Janeiro Brazil

ISBN: (纸本)9781905088546

The main objective of this paper is to investigate the influence of steel-concrete interaction degree (from total to various levels of partial interaction) over the nonlinear dynamic behaviour of composite floors when subjected to human rhythmic activities. The investigated structural model was based on a steel-concrete composite floor spanning 40m by 40m, with a total area of 1600m2. The structural system consisted of a typical composite floor of a commercial building. The peak accelerations found in the present analysis indicated that the investigated floor presented problems related with human comfort. Hence it was detected that this type of structure can reach high vibration levels that can compromise the user's comfort. © civil-Comp Press, 2012.

关键词： Floors

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Influence of CDW Recycled Aggregate on Drying Shrinkage of Mortar

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Open Journal of civil engineering 2012年第2期2卷 53-57页

作者： Paulo Roberto Lopes Lima Monica Batista Leite Civil and Environmental Engineering Post-Graduate Program State University of Feira de Santana Feira de Santana Bahia Brazil

The use of fine recycled aggregates as raw material in the production of mortars appears as a good alternative to minimize waste disposal, so as to reduce natural resources consumption and to find and supply suitable substitutes for natural aggregates. However, the use of this alternative material in a safe way must be carried out by a wide investigation of its long term behavior. In this way, this paper will examine the mechanical strength, physical properties and drying shrinkage of mortar, which use recycled fine aggregates that have originated from construction and demolition waste (CDW) containing mortar (55%), ceramic (26%) and concrete (16%). Two natural mortars, made with natural sand, were produced with cement/sand ratios of 1:4 and 1:8 (by weight) and a fixed consistency index of 260 +10 mm. Recycled mortar was produced with 50% of substitution rate, in volume, of natural aggregate by recycled one. Results show that recycled mortars present higher total porosity, absorption rate and drying shrinkage than reference mortar.

关键词： Recycled Mortar Construction and Demolition Waste Drying Shrinkage Recycled Aggregate

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Acoustic performance of closing panels used in steel-structured buildings

Acoustic performance of closing panels used in steel-structu...

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18th International Congress on Sound and Vibration 2011, ICSV 2011

作者： Ribas, Rovadávia A.J. Souza, Henor A. Civil Engineering Post-Graduate Program Universidade Federal de Ouro Preto Escola de Minas Campus Morro do Cruzeiro 35400-000 Ouro Preto - MG Brazil

ISBN: (纸本)9781618392596

In this research, it was made the evaluation of the acoustic performance of some closing systems mostly used in steel-structured buildings in Brazil, for instance walls made of the cement plates, precast concrete panels and plasterboard walls. The acoustic performance was evaluated by estimating the sound transmission loss that occurs through them using a simplified graphical method. It was studied the performance of these kinds of panels and their combinations forming double panels, with and without sound-absorbing material between them. Copyright © (2011) by the International Institute of Acoustics & Vibration.

关键词： Precast concrete

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Vibration analysis of a production platform induced by mechanical equipment

Vibration analysis of a production platform induced by mecha...

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10th International Conference on Computational Structures Technology, CST 2010

作者： Rimola, B.D. Da Silva, J.G.S. Sieira, A.C.C.F. De Lima, L.R.O. Da Neves, L.F.C. Civil Engineering Post-graduate Programme UERJ PGECIV State University of Rio de Janeiro Brazil Structural Engineering Department UERJ State University of Rio de Janeiro Brazil Civil Engineering Department University of Coimbra ISISE Portugal

ISBN: (纸本)9781905088386

The competitive trends of the world market have long been forcing structural engineers to develop minimum weight and labour cost solutions. A direct consequence of this new design trend is a considerable increase in problems related to unwanted floor vibrations. For this reason, the structural floors systems can become vulnerable to excessive vibrations, for example, produced by impacts such as mechanical equipments (rotating machinery). This way, the present paper investigated the dynamic behaviour of a production platform made of steel and located in Santos basin (Merluza field), São Paulo, Brazil, when subjected to impacts produced by mechanical equipments (rotating machinery). The structural model consists of two steel decks with a total area of 1915 m2 (upper deck: 445 m2 and lower deck: 1470 m2), supported by piles. A numerical analysis was made, in order to assess the dynamic impacts on the deck structure coming from the electrical generators and compressors. Based on the peak acceleration values, obtained on the structure steady-state response, it was possible to evaluate the structural model performance in terms of human comfort, maximum tolerances of the mechanical equipment and vibration serviceability limit states of the structural system. © civil-Comp Press, 2010.

关键词： Vibration analysis

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