UPCommons - E-prints UPC Universitat Politècnica de Catalunya
(51.501 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 117
1.
Reactions of fly ash with calcium aluminate cement and calcium sulphate - Fernández Carrasco, Lucía; Vázquez Ramonich, Enric
The hydration processes in the ternary system fly ash/calcium aluminate cement/calcium sulphate (FA/CAC/C$) at 20 °C were investigated; six compositions from the ternary system FA/CAC/C$ were selected for this study. The nature of the reaction products in these pastes were analysed by X-ray diffraction (XRD) and infrared spectroscopy (FTIR). At four days reaction time, the main hydration reaction product in these pastes was ettringite and the samples with major initial CAC presented minor ettringite but calcium aluminates hydrates. The amount of ettringite developed in the systems has no direct relation with the initial components.
3.
New analytical model to generalize the Barcelona Test using axial displacement - Pujadas Álvarez, Pablo; Blanco Álvarez, Ana; Pialarissi Cavalaro, Sergio Henr; Fuente Antequera, Albert de la; Aguado de Cea, Antonio
The Barcelona Test has proved to be very suitable for the systematic control of the tensile properties of Fibre Reinforced Concrete (FRC). Nevertheless, the need to measure the total circumferential opening displacement (TCOD) of the specimen entails the use of an expensive circumferential extensometer. In order to simplify the test, studies from the literature propose the use of the axial displacement of the press (δ) instead of the TCOD, obtaining empirical equations to correlate the energy estimated with both measurements. However, these equations are only valid for δ ranging from 1 to 4 mm and were adjusted based on the...
4.
Recycling silicon solar cell waste in cement-based systems - Fernández Carrasco, Lucía; Ferrer, R.; Aponte Hernández, Diego Fernando; Fernández, P.
This is a study of the recycling of crystalline solar cells by incorporating them in cement matrices. The hydration process of a mixture of calcium aluminate cement (CAC) and solar photovoltaic cell waste was researched and analyzed. The nature of the hydration products of various compositions of these mixtures was evaluated at a temperature of 20 1C by analyzing the samples through X-ray diffraction, infrared spectroscopy and scanning electron microscopy. The total porosity and mechanical strength development of these materials were also determined. It was revealed that the presence of a solar cell residue of up to 5% in the...
5.
Model for enhancing integrated identification, assessment, and operational control of on-site environmental impacts and health and safety risks in construction firms - Gangolells Solanellas, Marta; Casals Casanova, Miquel; Forcada Matheu, Núria; Fuertes Casals, Alba; Roca Ramon, Xavier
Certifiable management-system standards apply similar management techniques and principles, but each system still tends to have
a separate structure in construction companies. Research and practice have demonstrated that management tasks may be duplicated when
standards are implemented in parallel. Consequently, integrated management systems are strongly advocated. However, existing literature
demonstrates that the integration of planning and control instruments involves a high level of uncertainty. This paper presents an innovative
model to enhance the integration of environmental- and health and safety
–
management systems in construction companies, focusing on the
subsystems for identifying, assessing, and operationally controlling environmental aspects and health and safety hazards and using risk as...
6.
Diseño de mezclas de hormigón reciclado mediante el método Volumen de Mortero Equivalente (EMV): Validación bajo el contexto español y su adaptación al método de diseño de Bolomey - Jiménez Fernández, Cristian Gonzalo; Vázquez Ramonich, Enric; Barra Bizinotto, Marilda; Valls del Barrio, Susanna
El nuevo método para el diseño de hormigón con árido reciclado (HAR) es usado para
comprobar su posibilidad de uso bajo el contexto español. Primeramente, se realiza una extensa campaña experimental, para analizar las posibilidades de su aplicación, usando dos áridos reciclados de hormigón (ARH) españoles. En la segunda etapa se elabora una adaptación del método a la metodología propuesta por Bolomey (1), con 20% de reemplazo en peso de árido grueso natural (AN) por ARH, para así cumplir con las recomendaciones estipuladas en la
Instrucción de Hormigón Estructural (EHE 2008). Para determinar y analizar las propiedades del hormigón, se llevaron a...
7.
Design of macro-synthetic fibre reinforced concrete pipes - Fuente Antequera, Albert de la; Campos Escariz, Renata; Domingues de Figueiredo, Antonio; Aguado de Cea, Antonio
This paper presents an experimental campaign in which concrete pipes were manufactured using plastic fibres as the sole reinforcement material. In this regard, it has been demonstrated that the use of plastic
fibres is compatible with pipe production systems, and that, when subjected to the crushing test (CT), plastic fibre reinforced pipes yield strength classes that are attractive in terms of the growth of this material in the concrete pipe industry. Moreover, the results obtained from both the characterisation of the material and the mechanical behaviour of the pipes have been used to verify that the Model for the Analysis of...
8.
Influence of building type on post-handover defects in housing - Forcada Matheu, Núria; Macarulla Martí, Marcel; Fuertes Casals, Alba; Casals Casanova, Miquel; Gangolells Solanellas, Marta; Roca Ramon, Xavier
Clients’ lack of involvement in defining quality requirements for dwellings built by developers leads to a perception of poor quality at the time of purchase. The research presented in this paper aims to broaden previous research on defects by analyzing the defects that remain in the post-handover stage, which usually lasts 12 months after the handover period, and identifying the factors that influence the appearance of these defects, determining whether a significant difference exists in the quality of the two main residential building types built by developers: flats and detached houses. It also analyzes and discusses the areas and elements...
9.
Longitudinal time-dependent response of segmental tunnel linings - Arnau Delgado, Oriol; Molins i Borrell, Climent; Blom, C.B.M.; Walraven, Joost
The longitudinal forces introduced by tunnel boring machines (TBMs) to the segmental tunnel linings influence their structural response. The analyses of the linings construction process and the ground-structure interaction mechanisms have shown the influence of the lining creep on the progressive loss of the initial longitudinal force. An analytical formulation to predict the remaining compression of the linings as a function of time is proposed, supported by means of a complete numerical model, which considers the effect of creep during the sequential construction process. An experimental program to determine the creep of plastic packers was developed, revealing its significant influence...
10.
Three dimensional structural response of segmental tunnel linings - Arnau Delgado, Oriol; Molins i Borrell, Climent
The particular configuration of segmental tunnel linings produces that its structural response in front of usual design loads could present a significant three dimensionality due to the structural interaction between adjacent rings (coupling effects). The present paper studies the phenomena associated to coupling effects, determines the main involved parameters and analyzes their influence on a real lining structural response by means of a 3D numerical model. The comparison with the usual plane models currently employed in linings designs provide significant conclusions about the coupling effects implications and the conditions in which become more relevant.
11.
Tapered plate girders under shear : tests and numerical research - Bedynek, Agnieszka; Real Saladrigas, Esther; Mirambell Arrizabalaga, Enrique
This paper presents an experimental and numerical research on tapered steel plate girders subjected to shear. Experimental tests included four small-scale tapered steel plate girders. Research was focused on
both, critical shear load and ultimate shear resistance. Moreover, the post-buckling behaviour of tapered plates was studied.
Further, some parametric studies with various geometries of tapered panels were done in order to find the most favourable design situations. The analysed parameters were: the panel aspect ratio, the inclined
flange angle, the web and the flange slenderness.
Numerical simulations allowed distinguishing four different typologies of tapered plate girders which should be considered separately in design because...
14.
Assessment of residential defects at post-handover - Forcada Matheu, Núria; Macarulla Martí, Marcel; Love, Peter E.D.
In Spain, the Ley de Ordenación de la Edificación (Building Regulation Act) has established compulsory warranties to ensure that
buildings meet basic requirements with regard to functionality, general safety and structure, fireproofing, and use and habitability. Despite the
requirements of this regulatory body, defects in newly built dwellings remain a pervasive problem, which has resulted in a plethora of
complaints to the
Instituto Nacional del Consumo
(National Institute for Consumers
’
Protection), which deals with consumer protection
in Spain. In this paper, a total of 2,351 post-handover defects derived from four Spanish builders and seven residential developments
are classified according to their location, subcontract, and element. The research reveals...
15.
Tecnología para la sostenibilidad: ¿conveniencia o necesidad - Esquerra, Pere; Planas Rodríguez, Carla; Gallostra, Juan; Túnica, José
La Comunidad Europea editó la Directiva 92 sobre la eficiencia Energética de los Edificios en la que mostraba su preocupación por el aumento imparable de los consumos por causa del aire acondicionado. La eficiencia de
los equipos puede ser una de las repuestas, pero el uso de recursos naturales que no consuman energía debe tenerse en cuenta también, aplicando las reglas de la bioclimatización, que en algunos casos pueden ser las únicas
aplicables cuando la energía sea un bien escaso. En cualquier caso en los hospitales es necesario tener un control
de las condiciones climáticas, sean naturales las fuentes o no. La Tecnología...
16.
An orthotropic damage model for the analysis of masonry structures - Pelà, Luca; Cervera Ruiz, Miguel; Roca Fabregat, Pedro
This paper presents a numerical model for nonlinear analysis of masonry structural elements based on Continuum Damage Mechanics. The material is described at the macro-level, i.e. it is modeled as a homogeneous orthotropic continuum. The orthotropic behavior is simulated by means of an original methodology, resulting from the concept of mapped tensors from the anisotropic field to an auxiliary workspace.
The application of this idea to strain-based Continuum Damage Models is innovative and leads to several computational benefits. The suitability of the model for representing the behavior of different types of brickwork masonry is shown via the simulation of experimental tests.
17.
Análisis de la igualdad de oportunidades de género en la ciencia y la tecnologia: Las carreras profesionales de las mujeres científicas y tecnológas - Pons Peregort, Olga; Calvet Puig, Maria Dolors; Tura Solvas, Marta; Muñoz Illescas, Cristina
Analizar la igualdad de oportunidades de género en el ámbito de la Ciencia y la
Tecnología con el objetivo de conocer la trayectoria laboral de las mujeres científicas,
así como las principales dificultades que han asumido en su carrera profesional en la
promoción, la retribución y la conciliación de la vida personal y laboral. Analizar,
también, la situación de esas mujeres en otros países. Los resultados constatan la
desigualdad de género en la trayectoria de las carreras profesionales dedicadas a la
ciencia o la tecnología. El objetivo final de este estudio es conocer las aportaciones de
las mujeres que han desarrollado su carrera profesional en el ámbito...
18.
Generación automática de esquemas de bielas y tirantes considerando criterios constructivos - Bairán García, Jesús Miguel
El método de bielas y tirantes (BT) es de gran utilidad en el dimensionamiento a rotura de elementos de hormigón, particularmente en casos de regiones D donde las hipótesis clásicas de vigas y placas no son aplicables. Aunque el método viene recogido en muchas normativas modernas, existen al menos tres aspectos que limitan
un uso más extendido en la práctica: no da información en servicio, la selección de esquemas factibles no es trivial en casos complejos y la solución no es única. En este artículo se propone un método que genera esquemas factibles de BT mediante el uso de análisis lineales...
19.
Expansion of mortars with gypsum contaminated fine recycled aggregates - Tovar Rodríguez, Gustavo Enrique; Barra Bizinotto, Marilda; Pialarissi Cavalaro, Sergio Henr; Aponte Hernández, Diego Fernando; Vázquez Ramonich, Enric
This study evaluates the expansivity of fine recycled aggregates mortars depending on the type of Portland cement, the consistency and the equivalent of acid soluble sulphates (SO3) content. For that, an experimental campaign divided in two phases was performed. In the first phase, the cement pastes were produced and tested by means of X-rays diffractions in order to analyze the hydrated compounds formed over time. In the second phase mortars samples were cast in order to assess the physical and mechanical
properties as well as the expansion over time. The results showed that incorporation of gypsum contaminated fine recycled aggregates with...
20.
An ontology-based approach for on-site integrated environmental and health and safety management - Gangolells Solanellas, Marta; Casals Casanova, Miquel
Este artículo tiene como objetivo favorecer la implementación de sistemas integrados de gestión ambiental y de seguridad salud en empresas constructoras, centrándose en el subsistema de control de los impactos ambientales y los riesgos de seguridad y salud en obra.
La gran compatibilidad que presentan los requerimientos vinculados al control operacional establecidos en la normas ISO 14001:2004 y OHSAS 18001:2007 así como las interacciones existentes entre impactos ambientales y riesgos de seguridad y salud (Gangolells et al., 2009, Gangolells et al., 2010) han motivado el desarrollo de una ontología que permite construir un modelo integrado para el control operacional en obras...
1.
