Comunicaciones a congresos UPV

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En esta comunidad se tiene acceso al texto completo de Jornadas y Congresos organizados realizados en la Universitat Politècnica de València, (UPV). Su objetivo es aumentar la visibilidad de estos documentos, así como garantizar su preservación.

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Analysis of moisture state of recycled coarse aggregate and its influence on compression strength of the concrete
(Editorial Universitat Politècnica de València, 2009-12-15T13:07:46Z) Pelufo Carbonell, María José; Domingo Cabo, Alberto; Ulloa Mayorga, Vivian Andrea; Vergara Acuña, Needy Nayiv; Dpto. de Ingeniería de la Construcción y de Proyectos de Ingeniería Civil; Escuela Técnica Superior de Ingeniería de Caminos, Canales y Puertos
This article analyzes the impact of the moisture level of recycled coarse aggregate additions to concrete on its compression strength, with the goal of finding a logical development process that can be reproduced at an industrial level and provide acceptable results for concrete production. This study takes into account the reality in the process of the production of concrete; while many authors suggest the use of recycled coarse aggregates in a saturated state to ensure the desired ratio water to cement in the concrete, in reality, the aggregates are introduced unsaturated. The main objective of this study is to observe and analyze the behaviour of recycled coarse aggregate in concrete, so that it is not stigmatized by the extra work involved in its use. The concrete was produced using three states of the recycled coarse aggregates. In the first one, the aggregates were added in their natural state, taking into account the total water in the dosage; in the second one, aggregates were added after being submerged in water for 10 minutes and drained for 10 minutes; and in the last one, the aggregates were added in their natural state, taking into account its absorption when adding the water. In order to evaluate the recycled coarse aggregates¿ resistance to compression at 28 days, four percentages of replacement of the recycled coarse aggregates, 0%, 20%, 50% and 100% were established among the concretes studied. The study finds that to define the resistance of a concrete, the effective ratio of water to cement plays a very important role; basically, the high absorption of recycled aggregates directly affects the quality of the concrete. The results showed that the values of compressive strength increased as the replacement percentage of the recycled coarse aggregates increased when the aggregates were added in their natural state, not considering their absorption in the mixed water. The opposite result was obtained when the aggregates were added in saturated state, reflecting a significant decrease in the resistance of the concrete as the replacement percentage of recycled coarse aggregates increased.
Hybrid UHPFRC thin walled "¶" beams for flat roofing applications
(Editorial Universitat Politècnica de València, 2009-12-15T13:01:19Z) Camacho, Esteban; Serna Ros, Pedro; Dpto. de Ingeniería de la Construcción y de Proyectos de Ingeniería Civil; Escuela Técnica Superior de Ingeniería de Caminos, Canales y Puertos; Instituto Universitario de Investigación de Ciencia y Tecnología del Hormigón
The main hybrid UHPFRC properties are the high tensile strength it can achieve with a ductile behaviour and the close cracks it can develop during the strain-hardening, whereby its durability is improved. Those characteristics make this material especially suitable for carry tensile and flexural efforts in more slightly and new shapes elements, dispensing of conventional reinforcement. In this research, several hybrids UHPFRC mix compositions were designed and characterized for different levels of requirement in cost or strength, achieving values from 35 MPa to more than 45 MPa of equivalent linear elastic flexural tensile strength. The material composition includes high elastic limit steel fibres of two different sizes. Silica fume, aggregates type and qualities were also variables for this study in order to obtain different cost concretes. The workability of the mixture was designed for being high in order not to be compacted. A flat roof with similar purposes than conventional unidirectional flats was designed using thin walled ¿ cross section beams made with UHPFRC. Advantages on minimizing materials consumption, reducing self weight, construction procedures, transport facilities and other improvements make of this solution an interesting alternative to conventional solutions. To analyze the structural behaviour three thin walled ¿ cross section beams were made at actual dimensions in laboratory with different hybrid UHPFRC. Beams were tested in flexural four point bending tests. The load and associated deflection, the maximum load and cracking pattern were analysed and evaluated.
Model for the behavior of steel fibers reinforced concrete in plates elements
(Editorial Universitat Politècnica de València, 2009-12-18T10:50:26Z) LOPEZ-GAYARRE, Fernando; LOPEZ-COLINA, Carlos; Lázaro Fernández, Carlos Manuel; Pelufo Carbonell, María José; Domingo Cabo, Alberto; Dpto. de Ingeniería de la Construcción y de Proyectos de Ingeniería Civil; Dpto. de Mecánica de los Medios Continuos y Teoría de Estructuras; Escuela Técnica Superior de Ingeniería de Caminos, Canales y Puertos
This article presents and develops a model for the behavior of steel fibers reinforced concrete (SFRC) for its use in plates elements. In order to carry out the present investigation, a series of laboratory tests were made for the mechanical characterization of SFRC. Additionally, a set of plates elements were tested in the laboratory of Construction Engineering at the Technical University of Valencia, with different fiber contents and load conditions. These plates elements were tested to their fracture, and the obtained results were verified experimentally with the implementation of the given model in a program of finite elements, where the tested plates were modelized. The obtained results show a satisfactory adjustment of the given model for its application in nonlinear calculation of plates elements made with steel fibers reinforced concrete.
Movable structure for a two-axes solar tracker. Tracking a sustainalble future
(Editorial Universitat Politècnica de València, 2010-02-17T10:44:19Z) PALACIOS, Francisco J.; Lázaro Fernández, Carlos Manuel; Domingo Cabo, Alberto; Dpto. de Ingeniería de la Construcción y de Proyectos de Ingeniería Civil; Dpto. de Mecánica de los Medios Continuos y Teoría de Estructuras; Escuela Técnica Superior de Ingeniería de Caminos, Canales y Puertos
The population growth and development in underdeveloped countries has led to a rise in the demand for energy and the fact that conventional energy sources cause damage to the environment means that the sustainable future must be based on alternative energy sources. This paper describes an application of movable structures for alternative energy sources. We present the design of a movable structure-mechanism for an innovative two-axes solar tracker with a ratio between generated and consumed energy which is less than half the usual one for two-axes trackers. The device has minimum height (minimum environmental impact, easy assembly) and is strong and reliable.
Numerical analysis of steel fiber reinforced concrete shells
(Editorial Universitat Politècnica de València, 2009-12-23T10:27:24Z) RIBEIRO, Tatiana S. A.; Serna Ros, Pedro; Dpto. de Ingeniería de la Construcción y de Proyectos de Ingeniería Civil; Escuela Técnica Superior de Ingeniería de Caminos, Canales y Puertos; Instituto Universitario de Investigación de Ciencia y Tecnología del Hormigón
Here, a simple numerical model for steel fiber concrete, based on a reinforced concrete model is presented. In the proposed model concrete is modeled using a finite element dedicated to brittle materials, available at ANSYS library. Fiber contribution to the multiaxial state of concrete is modeled by changing concrete parameters accordingly. Moreover, stress transfer by fiber bridging action is taken in account by considering the fibers as an equivalent smeared reinforcement. An appropriate although simple model for fiber reinforced concrete is therefore obtained by suitably adjusting the parameters of a reinforced concrete model. The proposed model is applied to shells which are part of the Wall of the Benidorm esplanade (Spain). Analyses are carried out on wall segments, considering the structure self-weight, and temperature variations. The numerical results obtained represent well the structural behavior.
Sensitivity analysis of a stress strain model for steel fiber reinforced concrete plates
(Editorial Universitat Politècnica de València, 2009-12-17T10:32:31Z) LOPEZ-GAYARRE, Fernando; SERRANO, Miguel A.; Lázaro Fernández, Carlos Manuel; Domingo Cabo, Alberto; Pelufo Carbonell, María José; Dpto. de Ingeniería de la Construcción y de Proyectos de Ingeniería Civil; Dpto. de Mecánica de los Medios Continuos y Teoría de Estructuras; Escuela Técnica Superior de Ingeniería de Caminos, Canales y Puertos
This article deals with the sensitivity study of a given model for the behavior of thin laminar elements of SFRC (steel fiber reinforced concrete). In order to carry out this analysis, a brief description of the model used for the behavior of the SFRC in laminar elements is presented. The analysis was made by means of ABAQUS finite element software with a particular model for the behavior of SFRC. The limit of the fragile-plastic behavior of SFRC plates has been established as an outcome of the analysis. The results of test performed on plates were compared with the numerical simulation. Good correlation between experimental results and those obtained in the numerical simulation was observed as an adequate support for the model.
Structural analysis of the roof's shell of new terminal of the airport of Valencia (VLC)
(Editorial Universitat Politècnica de València, 2009-12-23T10:21:59Z) Moya Soriano, Juan Francisco; Llopis Camps, Carlos; Dpto. de Ingeniería de la Construcción y de Proyectos de Ingeniería Civil; Escuela Técnica Superior de Ingeniería de Caminos, Canales y Puertos
The social and economic current growth of the Valencian Community, and in particular of the city of Valencia, made necessary the presence of an airport adapted to the new reality of the city. A city immersed in a great number of events of world relevance; the America's Cup, the Formula 1 Grand Prix and the continuous touristic attraction of the City of the Arts and the Sciences had to be opened by a 'new entrance' that would match the forthcoming events that it would host in the same manner as the three grand gates of the city wall did in the past, of which only the Quart and Serrano's Torres remain. In this way the New Terminal of the Airport of Valencia becomes a new link to the outside world with its renewed image in accordance with what is waiting behind its doors.
Structural behavior of self-compacting and fiber reinforced concrete under shear loading
(Editorial Universitat Politècnica de València, 2009-12-15T13:03:23Z) Cuenca, Estefanía; Serna Ros, Pedro; Pelufo Carbonell, María José; Dpto. de Ingeniería de la Construcción y de Proyectos de Ingeniería Civil; Escuela Técnica Superior de Ingeniería de Caminos, Canales y Puertos; Instituto Universitario de Investigación de Ciencia y Tecnología del Hormigón
Shear behavior of concrete elements made with traditional concrete (TC), self-compacting concrete (SCC) and fiber reinforced concrete (FRC) was analyzed. Three reinforced concrete beams were tested using three different kinds of concrete: TC, SCC and FRC, and two prestressed reinforced beams with SCC and FRC. Minimum traditional shear reinforcement was fixed so that a shear failure took place. Displacements, load and crack width were measured during the tests. Subsequently, the values obtained during the tests were analyzed by comparing the results of the different kinds of concrete. By means of video recording and subsequent image analysis, crack widths in beams were measured. Crack opening was controlled at the fixed control points. Shear experimental strength and behavior were compared. A safety margin was obtained for the analyzed cases.
A study on drying shrinkage and creep of recycled concrete aggregate
(Editorial Universitat Politècnica de València, 2009-12-18T10:50:01Z) CASTAÑO, Jesus O.; LOPEZ-GAYARRE, Fernando; Lázaro Fernández, Carlos Manuel; Domingo Cabo, Alberto; Dpto. de Ingeniería de la Construcción y de Proyectos de Ingeniería Civil; Dpto. de Mecánica de los Medios Continuos y Teoría de Estructuras; Escuela Técnica Superior de Ingeniería de Caminos, Canales y Puertos
Although it is not a new material, in the last years the recycled aggregates of concrete RCA have had a great progress and are highly valued because of being friendly with the environment, multiple studies find feasible their use in structural concrete but when it is intended to be used in singular structures or prefabricated pieces that require high performance levels an exhaustive evaluation of its properties dealing with deformation and durability are needed. The paper presents an experimental study on drying shrinkage and creep of recycled concrete at constant standard ambient conditions, 8 concrete mixtures with 2 water/cement ratio (0,5 and 0,65) and 4 substitution levels of natural coarse aggregates by recycled concrete aggregates (0%, 20%, 50% and 100%) were used and the influence on this two important time-dependent deformations of recycled concrete were examined in conformity the ASTM C 512 for creep and UNE 83-318-94 for shrinkage. The effects of recycled concrete aggregates on the mechanical properties were analyzed and coefficients and recommendations to fit design are provided. The experimental results showed that the recycled aggregate have a significant effect on the overall elastic properties of concrete, the creep and drying shrinkage increases considerably, as the substitution level increases, without a lineal relation with the elasticity modulus variation when high performance concrete is used.

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