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UPCommons - E-prints UPC Universitat Politècnica de Catalunya (83,371 recursos)
E-prints UPC cobreix dues finalitats: per una banda, és el dipòsit institucional de la UPC que recull els articles de revista, les comunicacions de congrés i els reports de recerca generats en les activitats de recerca del personal docent i investigador de la universitat; per l'altra, és una eina que permet accelerar la producció científica, allotjant versions de documents prèvies a la publicació en una revista o a les actes d’un congrés.

Articles de revista

Mostrando recursos 1 - 20 de 203

1. Effect of mix design on fresh self-consolidating concrete and inferences on formwork pressure - Ruiz Ripoll, Lidia; Shah, Surendra; Barragán, Bryan Erick; Turmo Coderque, José
The use of self-consolidating concrete (SCC) has become more prevalent due to its economic and technological advantages over other types of concrete. Nevertheless, issues relating to casting and placement hinder its widespread use. One of the primary concerns of using SCC is related to its high formwork pressure, which affects any type of structural element, whether it is precast or cast on site. This study aimed to make correlations between different parameters obtained through slump flow and shear rheological tests in order to determine what the implication would be on the evolution of formwork pressure for five typical precast SCC...

2. Application of constitutive models in European codes to RC-FRC - Blanco Álvarez, Ana; Pujadas Álvarez, Pablo; Fuente Antequera, Albert de la; Pialarissi Cavalaro, Sergio Henrique; Aguado de Cea, Antonio
The recent publication of codes for the design of FRC is a major step towards extending the use of the material. An in depth analysis indicates several differences between the constitutive models proposed in the existing codes. In this study, these models are compared and a numerical simulation is performed to evaluate their differences in terms of the structural behavior predicted and measured in an experimental program of RC-FRC elements. The predictions provided by the models fit satisfactorily the experimental results for elements with steel fibers and with plastic fibers

3. Case study of damage on masonry buildings produced by tunneling induced settlements - Camós Andreu, Carles; Molins i Borrell, Climent; Arnau Delgado, Oriol
This study analyzes the structural response of a group of masonry buildings subjected to real ground movements experienced during the construction of the L9 Metro tunnel in Barcelona, bored by a earth pressure balance machine (EPB) tunnel boring machine (TBM). The studied one-story small dwellings represent a common building typology frequently used in those days in Barcelona's outskirts (more than 1000 were erected). Real settlement profiles are compared with the ones provided by empirical methods, which estimate the shape and the area of the trough according to the ground properties and the volume loss. The first aim of the study...

4. Application of particle motion technique to structural modal identification of heritage buildings - Caselles Magallón, Josep Oriol; Martínez, Guillermo; Clapes Boixader, Jaime; Roca Fabregat, Pedro; Pérez Gracia, María de la Vega
Determining the behavior of a structure estimated by means of finite elements analysis requires not only an in-depth knowledge of its geometry and dynamic properties but also an experimental validation to corroborate the adequacy of the characteristics of the structure. Most of the current structural identification techniques are based on linear methods that call for many measurement points and/or a relative simple structure. Complex structures are somewhat still an unexplored field due to the difficulties with the finite element method and the experimental corroboration of its results. This study presents the use of particle motion computation applied to each structural vibration...

5. Application of particle motion technique to structural modal identification of heritage buildings - Caselles Magallón, Josep Oriol; Martínez, Guillermo; Clapes Boixader, Jaime; Roca Fabregat, Pedro; Pérez Gracia, María de la Vega
Determining the behavior of a structure estimated by means of finite elements analysis requires not only an in-depth knowledge of its geometry and dynamic properties but also an experimental validation to corroborate the adequacy of the characteristics of the structure. Most of the current structural identification techniques are based on linear methods that call for many measurement points and/or a relative simple structure. Complex structures are somewhat still an unexplored field due to the difficulties with the finite element method and the experimental corroboration of its results. This study presents the use of particle motion computation applied to each structural vibration...

6. Seismic behavior of medium and high strength concrete buildings - Bairán García, Jesús Miguel; Moreno González, Rosángel; Peguero, J.
Current concrete technology has made higher concrete grades more affordable to mid and high-rise buildings; hence its use has been increasing in the late years as it allows for smaller cross-sections, reduction of the structure’s weight, improve durability, among other benefits. However, it is known that brittleness of plain concrete increases with the strength; therefore, some national codes have limited the concrete’s strength in high seismic zones. In this paper, the seismic behavior of a 10 storey dual frame-wall building, designed with concrete grades C30, C60 and C90 is studied in order to assess the advantages and disadvantages of this material...

7. Numerical analysis of the load-bearing capacity of brick masonry walls strengthened with textile reinforced mortar and subjected to eccentric compressive loading - Bernat Masó, Ernest; Gil Espert, Lluís; Roca Fabregat, Pedro
There is little research about the numerical modelling of brick masonry walls strengthened with Textile Reinforced Mortar (TRM) against second order bending effects. Thus, a numerical model has been implemented to cover this knowledge gap. It has been validated by comparison with experimental cases and applied to enhance the knowledge about the influence of different strengthening variables. The model is accurate at predicting the load-bearing capacity of walls and points out that strengthening both sides might cause a remarkable increase of the load-bearing capacity and that the performance of the TRM is greater for the most slender cases.

8. Preventive intervention in a group of building located in the histotic centre of Manresa (Barcelona) - Díaz Gómez, César; Cornadó Bardón, Còssima; Griera Cura, Antoni; Caselles Magallón, Josep Oriol; Alegre Heitzmann, Vicente; Santamaria Garcia, Pere
The preservation of old downtowns has become a necessity of growing interest. New urban policies have been approved in different countries in order to revive the old city centers and make them economically sustainable. In this global trend, the municipality of Manresa (Barcelona) developed an important urban planning operation in the old district that included the demolition of a group of existing buildings and the construction of a new modern one in close proximity to a group of old residential buildings which are cultural heritage of the city. As a consequence, specific areas of risk were generated which lead to...

9. Experimental and analytical study of concrete blocks subjected to concentrated loads with an application to TBM-constructed tunnels - Liao, Lin; Fuente Antequera, Albert de la; Pialarissi Cavalaro, Sergio Henrique; Aguado de Cea, Antonio; Carbonari, Gilberto
To generate enough thrust for a Tunnel Boring Machine (TBM) to excavate a soil and advance, several jacks are typically used to apply force to the last installed ring that acts as a reaction frame. These loads generate bursting stresses that might cause cracks in the longitudinal direction of the segments. Many studies dedicated to evaluate this phenomenon focus mainly on elements with similar height-to-length ratios. To cover the wide variety of dimensions and load application patterns, additional experimental assessments are required. The objectives of the present paper are to extend the study of with different height-to-length ratios subjected to...

10. Numerical prediction of the behavior, strength and elasticity of masonry in compression - Drougkas, Anastasios; Roca Fabregat, Pedro; Molins i Borrell, Climent
The paper focuses on the numerical prediction of the compressive response of masonry by means of detailed micro-modeling techniques. In such a model, the material constituents (mortar and units) and the unit-mortar interfaces are separately described by means of specific constitutive equations.; The available modeling choices are evaluated through a literature review of related case studies. A systematic approach is proposed and is corroborated by the numerical simulation of a large number of experimental cases from various sources. A total of fifty experimental results are simulated resulting in an overall good prediction of the compressive strength and elastic modulus of...

11. Numerical modelling with experimental validation applied to the study of stud connectors behaviour in concrete and steel composite structures - Bonilla, Jorge; Bezerra, Luciano M.; Larrúa, Rafael; Recarey Morfa, Carlos Alexander; Mirambell Arrizabalaga, Enrique
In this work, the behaviour of stud shear connectors in composite structures is studied, starting from the via numeric simulation of the push out test in a steel beam – with solid concrete slab concrete section is studied. The study considers material non-linearity material of concrete and steel, adopting firstly a bilinear model for both (steel and concrete), and in the second case, to the difference ofdiffering from other authors, the concrete damage plasticity of the concrete. ABAQUS is used to model the push out test. The basis and methodology of the modelmodelling process push out test are explained. The...

12. Double-punch test of fiber-reinforced concrete: effect of specimen origin and size - Aire, Carlos; Carmona Malatesta, Sergio; Aguado de Cea, Antonio; Molins i Borrell, Climent
One of the main advantages of the Barcelona test is that the properties of fiber-reinforced concrete (FRC) can be determined by using cylindrical specimens, thereby permitting the use of cores to control the quality of concrete used in construction.; Using the results of an extensive experimental campaign, this paper establishes the relationship between the unitary load of cracking, residual strength and toughness of molded specimens, and cores of concretes reinforced with different types of fibers but with the same aspect ratio. The fiber diameter is observed to signifidantly influence the properties of molded specimens, whereas in the cores, the number...

13. Computing voter transitions: The elections for the Catalan parliament, from 2010 to 2012 - Corominas Subias, Albert; Lusa García, Amaia; Calvet Puig, Maria Dolors
Purpose: To estimate the transition rates corresponding to the 2010 and 2012 elections to the Catalan Parliament for the four constituencies in which Catalonia is divided for this purpose. The main features of the results, which are obtained by means of mathematical programming, are commented. Design/methodology/approach: Mathematical programming optimization models are formulated in order to find the transition rates that yield a better adjust between the actual results in 2012 and those computed applying the transition rates to the 2010 results. The transition rate matrices are estimated for each one of the four constituencies, since the set of options is...

14. Effect of fine ceramic recycled aggregate (RA) and mixed fine RA on hardened propertiesof concrete - Etxeberria Larrañaga, Miren; Vegas, Iñigo
The ceramic industry is well known for producing large amounts of rejected ceramic waste. During the construction and demolition waste crushing process, a large amount of fine recycled aggregates (FRA) are usually produced. However, little research work has been carried out employing those types of aggregates in recycled aggregate concrete (RAC) production. In this research work, mixed and ceramic FRA in partial replacement of 10, 20, 35 and 50% of natural fine aggregates were used in order to verify their applicability in RAC manufacturing. All the concretes were produced to have the same workability. The physical, mechanical and durability properties...

15. Improved assessment of fibre content and orientation with inductive method in SFRC - Pialarissi Cavalaro, Sergio Henrique; López Carreño, Rubén-Daniel; Torrents Dolz, Josep M.; Aguado de Cea, Antonio
The inductive method is a robust and simple non-destructive test to assess the content and the distribution of steel fibres in FRC. Despite the advantages in comparison with other methods, further studies are still needed to define the accuracy, the theoretical basis and the equations for the conversion of the inductance into fibre content and distribution. In fact, although the test provides an indirect estimation of the fibre distribution, currently no equation exists for the assessment of the orientation number, which is a valuable parameter for the design of structures. The objective of the present paper is to address this...

16. Experimental study about the effects of granular skeleton distribution on the mechanical properties of self-compacting concrete (SCC) - Santos, Ana C. P.; Ortiz Lozano, José Ángel; Villegas, Noe; Aguado de Cea, Antonio
In recent years, the use of self-compacting concrete (SCC) has been increasing. Although methods for designing the mixture proportions usually derive from experience with conventional concretes, some specific procedures still are not universally accepted. The design and characterization of SCC influences not only the mix components (paste volume and nature, binder amount and type, granular skeleton, etc.) but also the testing methods used to validate the self-compactability (usually in terms of rheology, fluidity, viscosity and resistance to segregation). This paper studies the influence on SCC mechanical properties based on the consideration of two types of granular skeleton, discontinuous and continuous,...

17. Influence of barite aggregate friability on mixing process and mechanical properties of concrete - González-Ortega, Martha Alejandra; Pialarissi Cavalaro, Sergio Henrique; Aguado de Cea, Antonio
The main objective of this paper is to evaluate the friability of the barite aggregate during the mixing process and its influence on the fresh and hardened properties of concrete. Three types of aggregates were studied: barite (in two states, dry and wet), limestone and EAF slag. A specific test was designed in which each type of aggregate was exposed to several times of mixing to evaluate possible changes to the grading curves and in the surface of the aggregates grains. Moreover, four types of concretes were designed (two with barite, one with EAF slag aggregate and one with conventional...

18. Experimental analysis of properties of high performance recycled aggregate concrete - Gonzàlez Corominas, Andreu; Etxeberria Larrañaga, Miren
Due to the increase in the demolition of high strength concrete structures and the interest of precast concrete companies in being more competitive, it is necessary to analyse the use of recycled concrete aggregates (RCA) in high performance concrete (HPC). In this study, HPC were produced using 20%, 50% and 100% of RCA on substitution of natural coarse aggregates. Three types of RCA were used, they were produced crushing original concrete of 100, 60 and 40 MPa of compressive strength. The physical, mechanical and durability properties of the recycled aggregates concretes and conventional concrete were analyzed. The results showed that...

19. Properties of high performance concrete made with recycled fine ceramic and coarse mixed aggregates - Gonzàlez Corominas, Andreu; Etxeberria Larrañaga, Miren
There are various means of obtaining waste for the production of recycled aggregates. In this study the waste material has been obtained from building demolition and also from the ceramic industry (known for the production of large amounts of rejected ceramic wastes). High performance concretes (HPC) was produced using fine ceramic aggregates (FCA) in substitution of 15% and 30% of natural sand, and using 20%, 50% and 100% of coarse mixed aggregates (CMA) on substitution of natural coarse aggregates. The physical, mechanical and durability properties of the recycled aggregate concretes were determined and compared to those of the results of...

20. Residue strength, water absorption and pore size distributions of recycled aggregate concrete after exposure to elevated temperatures - Kou, Shi-Cong; Poon, Chi-Sun; Etxeberria Larrañaga, Miren
In this paper, the effects of high temperature exposure of recycled aggregate concretes in terms of residual strengths, capillary water absorption capacity and pore size distribution are discussed. Two mineral admixtures, fly ash (FA) and ground granulated blast furnace (GGBS) were used in the experiment to partially replace ordinary Portland cement for concrete production. The water to cementitious materials ratio was maintained at 0.50 for all the concrete mixes. The replacement levels of natural aggregates by recycled aggregates were at 0%, 50% and 100%. The concretes were exposed separately to 300 °C, 500 °C and 800 °C, and the compressive...

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