http://hdl.handle.net/2117/215 2013-06-20T00:47:21Z http://hdl.handle.net/2117/19571 Title: Experimental study on resistance to cracking of bituminous mixtures using the Fénix Test Authors: Pérez Jiménez, Félix Edmundo; Botella Nieto, Ramón; Valdés Vidal, Gonzalo Abstract: The Road Research Laboratory of the Technical University of Catalonia (UPC) has developed a new tensile test called Fénix test. The objective of this test is to evaluate bituminous mixture crack behaviour. It is a simple procedure and has a low cost set up. The aim of this paper is to present Fénix test as a procedure to determine crack resistance through calculation of dissipated energy during the process. Test procedure and data analysis are shown for different types of mixtures. Variables studied were load application velocity, aging, binder type, binder content, test temperature and compaction temperature. As a result, authors found out that Fénix test is an effective procedure to determine mechanical properties regarding cracking resistance of bituminous mixtures. 2013-06-18T16:02:03Z http://hdl.handle.net/2117/19556 Title: An analytical solution to study substrate-microbial dynamics in soils Authors: Sánchez Vila, Francisco Javier; Rubol, Simonetta; Carles Brangari, Albert; Fernández García, Daniel Abstract: We provide an approximate analytical solution for the substrate-microbial dynamics of the organic carbon cycle in natural soils under hydro-climatic variable forcing conditions. The model involves mass balance in two carbon pools: substrate and biomass. The analytical solution is based on a perturbative solution of concentrations, and can properly reproduce the numerical solutions for the full non-linear problem in a system evolving towards a steady state regime governed by the amount of labile carbon supplied to the system. The substrate and the biomass pools exhibit two distinct behaviors depending on whether the amount of carbon supplied is below or above a given threshold. In the latter case, the concentration versus time curves are always monotonic. Contrarily, in the former case the C-pool concentrations present oscillations, allowing the reproduction of non-monotonic small-scale biomass concentration data in a natural soil, observed so far only in short-term experiments in the rhizosphere. Our results illustrate the theoretical dependence of oscillations from soil moisture and temperature and how they may be masked at intermediate scales due to the superposition of solutions with spatially variable parameters. 2013-06-14T13:59:57Z http://hdl.handle.net/2117/19555 Title: An environmental impact causal model for improving the environmental performance of construction processes Authors: Fuertes Casals, Alba; Casals Casanova, Miquel; Gangolells Solanellas, Marta; Forcada Matheu, Núria; Macarulla Martí, Marcel; Roca Ramon, Xavier Abstract: Despite the increasing efforts made by the construction sector to reduce the environmental impact of their processes, construction sites are still a major source of pollution and adverse impacts on the environment. This paper aims to improve the understanding of construction-related environmental impacts by identifying on-site causal factors and associated immediate circumstances during construc- tion processes for residential building projects. Based on the literature and focus group fi ndings, we have developed a construction-related Environmental Impact Causal Model consisting of a process-oriented causal network of thirty-nine environmental impacts, forty- fi ve causal factors and over two hundred causal relationships. It is intended to contribute to a reduction in construction-related environmental impacts on building sites by supporting contractors and other decision-makers in the early identi fi cation of factors that are likely to lead to impacts or to exacerbate their consequences, as well as the later environmental performance evaluation and control. The causal model is validated by investigating over a hundred environmental incidents. Finally, possible methods to improve construction-related environ- mental performance are suggested. 2013-06-14T13:57:28Z http://hdl.handle.net/2117/19554 Title: Relationship between binder and mixture damage resistance at intermediate and low temperatures Authors: Clopotel, Cristian S.; Velasquez, Raul; Bahia, Hussain U.; Pérez Jiménez, Félix Edmundo; Miró Recasens, José Rodrigo; Botella Nieto, Ramón Abstract: The importance of binder performance on the mixture response to accelerated fatigue loading and thermal cracking was investigated. Binder’s fatigue performance was measured by means of the Linear Amplitude Sweep test (LAS) while fatigue properties of the mixtures were investigated by performing the EBADE test. The low temperature properties of the binders were investigated by measuring the glass transition temperature and fracture properties with the Single Edge Notched Beam (SENB) test. The mixtures fracture properties were investigated using the FENIX test. The experimental matrix for this study included unmodified and rubber-modified binders and limestone aggregates. A good correlation between binder and mixture fracture energy was observed at low temperatures. This good correlation indicates the importance of fracture response of the binder to the overall low temperature cracking performance of the mixture. Experimental results suggest that a significant part of the variation of the fracture energy of the mixture can be explained by the binder fracture properties. Good correlations were also obtained for the displacement at maximum load in the SENB and Fenix tests. Similar accelerated fatigue response for binders and mixtures were observed when the stresses and strains were normalized. Significant reduction in the stress happened at about the same normalized strain in the binder and mixture. It can be seen that the mixture has remaining strength after reaching peak stress probably due to the aggregate structure. 2013-06-14T13:52:11Z http://hdl.handle.net/2117/19553 Title: Fibras de celulosa aditivadas para mezclas tipo SMA con propiedades mejoradas Authors: Lanchas, Santiago; Núñez, Ruy; Costa, Andrés; Loma, Javier; Cervantes, Rocío; Hidalgo, María Elena; Hergueta, José Antonio; Sánchez, Fernando; Rubio, Baltasar; Jiménez, Rafael; Pérez Jiménez, Félix Edmundo; Botella Nieto, Ramón; Expósito, Santiago; Fernández, Victoriano; Potti, Juan José Abstract: Las mezclas bituminosas tipo SMA, recogidas en la norma UNE EN 13108-5, ofrecen grandes posibilidades para aumentar la vida útil de las capas del firme, principalmente las de rodadura e intermedia, contribuyendo así a la reducción de costes en el ciclo de vida de la estructura portante de la carretera. El proyecto Mezclas SMA de la familia de la norma UNE EN 13108-5 que sean Sostenibles, Medioambientalmente Amigables (Proyecto SMA, Financiado por el Centro Tecnológico para el Desarrollo Industrial, CDTI, con fondos FEDER) consta de dos grandes partes. Una primera dedicada a la adaptación a las condiciones españolas de las mezclas SMA convencionales. Una segunda parte enfocada al desarrollo de mezclas que basándose en los principios constitutivos de las SMA convencionales, permitan la potenciación de aspectos relacionados con la reducción del impacto medioambiental y contribuyan a la mayor sostenibilidad de la construcción y conservación de los firmes de carreteras. Es conocido que las mezclas SMA requieren una fibra estabilizante para evitar los problemas de drenaje del ligante asociados a los altos contenidos del mismo. También favorecen un reparto homogéneo del mástico formando una película gruesa y homogénea alrededor de los áridos. Pero las mezclas SMA especiales desarrolladas en el Proyecto SMA han requerido el desarrollo de aditivos estabilizantes especiales que facilitasen y/o potenciasen las propiedades perseguidas. Este artículo presenta estos nuevos productos y las ventajas que permiten conseguir en la fabricación de mezclas bituminosas de prestaciones especiales. 2013-06-13T16:32:58Z http://hdl.handle.net/2117/19552 Title: Resistencia a la fisuración de las mezclas SMA Authors: Botella Nieto, Ramón; Pérez Jiménez, Félix Edmundo; Costa, Andrés; Cervantes, Rocío; Loma, Javier; Hidalgo, María Elena; Lanchas, Santiago; Núñez, Ruy; Rubio, Baltasar; Jiménez, Rafael; Hergueta, José Antonio; Sánchez, Fernanado; Expósito, Santiago; Fernández, Victoriano; Potti, Juan José Abstract: La resistencia a la fisuración es una de las propiedades de las mezclas bituminosas que más preocupa a los técnicos de pavimentos, y, en consecuencia, es de especial interés cualquier estudio que aporte nueva información sobre el tema. Estudios previos indican que las mezclas bituminosas tipo SMA, recogidas en la norma UNE EN 13108-5, pueden ser especialmente buenas en este aspecto, resistentes a la fisuración. Esto puede ser debido a su granulometría, su elevado contenido de ligante, el empleo de ligantes modificados en su fabricación y/o la adición de fibras. En esta comunicación se presentan los trabajos realizados en el marco del Proyecto SMA, financiado por el Centro Tecnológico para el Desarrollo Industrial (CDTI) con fondos FEDER, enfocados a analizar mediante ensayos de laboratorio la resistencia a la fisuración de este tipo de mezclas, tanto bajo cargas cíclicas como estáticas. El estudio se ha basado en la aplicación de tres tipos de ensayos: el ensayo de fatiga a flexotracción en 4 puntos, UNE-EN 12697-24, el ensayo cíclico uniaxial de barrido de deformaciones EBADE y el ensayo estático monotónico de tracción directa Fénix. Los resultados obtenidos muestran que las mezclas tipo SMA, en general presentan una ductilidad muy superior a la de las mezclas convencionales tipo AC, lo que favorecería su resistencia a la fisuración. En particular, esta propiedad las convierte en una opción muy interesante como capas de rodadura resistentes al envejecimiento y a la fisuración. 2013-06-13T16:29:36Z http://hdl.handle.net/2117/19551 Title: Mezclas SMA (Stone Mastic Asphalt) con alto contenido de ligante Authors: Costa, Andrés; Cervantes, Rocío; Loma, Javier; Hidalgo, María Elena; Hergueta, José Antonio; Sánchez, Fernando; Lanchas, Santiago; Núñez, Ruy; Rubio, Baltasar; Jiménez, Rafael; Pérez Jiménez, Félix Edmundo; Botella Nieto, Ramón; Expósito, Santiago; Fernández, Victoriano; Potti, Juan José Abstract: Las denominadas mezclas bituminosas en caliente SMA (Stone Mastic Asphalt) están recogidas en la normativa UNE EN 13108-5 y aunque en España apenas se han utilizado, su uso esta extendido por todo el mundo. Un grupo de empresas y algunos centros de investigación españoles, estamos desarrollando un proyecto de investigación denominado: Mezclas SMA de la familia de la norma UNE EN 13108-5 que sean Sostenibles y Medioambientalmente Amigables. Financiado por el Centro Tecnológico para el Desarrollo Industrial (CDTI) con fondos FEDER y que se desarrolla entre 2010 y 2012 ambos inclusive. Este proyecto tiene por objetivo el desarrollo de unas mezclas de la familia SMA que las hagan más sostenibles y contribuyan a mejorar el medioambiente. Entre los distintos tipos de mezclas SMA especiales (que hemos denominado XSMA) se han investigado y desarrollado un tipo de mezcla con un mayor contenido de betún (entorno a 8,5-9,5%) frente al 6% generalmente empleado en las mezclas SMA actuales, consiguiendo de esta forma mejorar la durabilidad de la mezcla, como mínimo, en un 25% más, medida, entre otros ensayos, a través de su comportamiento a fatiga así como su excelente comportamiento anti reflexión de grietas de capas tratadas con conglomerantes hidráulicos. La comunicación describe el trabajo de diseño en laboratorio de este tipo de mezcla, las dos mezclas XSMA 11 y XSMA 16 con alto contenido de ligante que se han puesto a punto y la realización de un tramo de ensayo a escala real, con este tipo de mezcla SMA, en la carretera CV-50 en Valencia. 2013-06-13T16:26:04Z http://hdl.handle.net/2117/19510 Title: Progressive emergence of double porosity in a silt during compaction Authors: Casini, Francesca; Vaunat, Jean; Romero Morales, Enrique Edgar; Desideri, Augusto Abstract: The paper deals with an experimental investigation of water retention properties of a statically compacted unsaturated low plasticity silt. The objective is a deeper understanding of the evolution of an aggregate type fabric at different initial conditions in terms of void ratio and water content. A series of Mercury Intrusion Porosimetry tests (MIP) were performed to provide information about factors influencing fabric changes (effect of mechanical stress due to sample compaction) and fabric-properties relationships (water retention curve related to porosimetry). The arrangements of aggregation/particles are also investigated with Environmental Scanning Electron Microscopy (ESEM). The experimental data has been used to calibrate a multimodal water retention model for aggregate which is obtained by linear superposition of sub-curves of the van Genuchten type modified. By comparing the WRC obtained by MIP and under suction controlled conditions it has been found a good agreement between the two method for the drying path. 2013-06-04T18:13:50Z http://hdl.handle.net/2117/19509 Title: Laboratory experiments on swelling due to crystal growth in sulphate argillaceous rocks Authors: Deu, Amadeu; Romero Morales, Enrique Edgar; Berdugo de Moya, Iván Rafael Abstract: Crystal growth is a frequent cause of expansive deformations in natural soils, compacted soils, rocks and concrete. The sulphate crystallization in discontinuities and cracks due to evaporation of highly mineralized solutions can contribute in an important way to displacements and swelling pressures that usually appear in tunnels and deep foundations in argillaceous rocks. The present work is aimed to study the basic mechanisms that control the hydrated sulphate mineral growth in anhydritic-gypsiferous argillaceous rocks due to the evaporation of groundwater. The paper presents some laboratory works including mineralogical and micro-structural analysis, as well as the design and development of new free swelling tests which were developed focusing on the capacity to discern the role carried out by the geochemical properties of the water, the main environmental variables and the degree of cracking on undisturbed sulphate argillaceous samples from different zones of the Lower Ebro Basin (Catalonia, Spain). 2013-06-04T18:08:46Z http://hdl.handle.net/2117/19508 Title: Effects of relative humidity cycling on the hydro-mechanical behaviour of two clayey rocks from North-East Spain Authors: Pineda Jiménez, Jubert Andrés; Alonso Pérez de Agreda, Eduardo Abstract: The paper describes the results of an experimental research aimed at studying the effects of relative humidity cycling on the degradation phenomena of two clayey rocks from North-East Spain, with particular emphasis on peak shear strength, low-strain stiffness and water permeability. Undisturbed samples were subjected to an extreme relative humidity cycle (between 15% and 99%) using the vapour transfer technique, before performing triaxial compression and water permeability tests. Rock stiffness was evaluated by ultrasonic pulse tests. Test results showed clear differences in stiffness and shear strength response between undisturbed and degraded samples, highlighting the relevance of hydraulically induced degradation phenomena on this type of materials. 2013-06-04T18:03:22Z http://hdl.handle.net/2117/19507 Title: Volumetric behavior of unsaturated-reconstituted soils Authors: Burton, G. J.; Sheng, Daichao; Romero Morales, Enrique Edgar Abstract: The vast majority of unsaturated soil research is completed on compacted soils. Due to ease of laboratory testing, specimens are typically prepared dry of optimum and often with high void ratios (low dry density) to capture the phenomena of collapse. Compacted soils have significant impacts on infrastructure, but the inherent effects of structure within each sample are difficult to differentiate from the effects of suction (and degree of saturation) in the laboratory. Although significant advances have been made with techniques such as MIP and ESEM. The difficulties of producing and unsaturated sample from slurry have largely limited the amount of published literature on samples reconstituted from slurry. In this paper, the available published data sets of Jennings and Burland (1962), Vicol (1990) and Cunningham (2000) are reviewed. Predictions of the volume change behavior are then made. 2013-06-04T17:55:03Z http://hdl.handle.net/2117/19506 Title: A practical method for suction estimation in unsaturated soil testing Authors: Amaral, M.F.; Viana da Fonseca, A.; Romero Morales, Enrique Edgar; Arroyo Alvarez de Toledo, Marcos Abstract: This research presents an alternative methodology to estimate suction in triaxial tests carried out under constant water content. A preliminary determination of the retention curve is proposed using two complementary techniques, namely psychrometer measurements and mercury intrusion porosimetry results. Starting with the definition of a set of retention curves at different void ratios, an attempt is made for establishing a correspondence of the measured retention curves with the results of a high pressure isotropic compression test. From the stress-paths followed in a soil-cement specimen during isotropic compression, plotted in the void ratio-stress plane, the suction is interpolated by using the previously measured values and the evolution law describing suction as a function of the specimen’s void ratio. For the aforementioned paths, the suction for all stress state points is estimated, including for the apparent yield pressure. 2013-06-04T17:52:00Z http://hdl.handle.net/2117/19505 Title: Effect of loading and suction history on time dependent deformation of coarse crushed slate Authors: Romero Morales, Enrique Edgar; Alvarado, Clara; Alonso Pérez de Agreda, Eduardo Abstract: The paper presents the results of an experimental investigation aimed at evaluating the time-dependent compressibility of coarse crushed quartzitic slate, focusing on the effects of the previ- ous loading and hydraulic history. Long-term and large diameter compression tests under oedometer conditions were performed at different total suctions (relative humidity values) and vertical stresses but following different loading and hydraulic paths. A finding, which has practical implications in earthwork constructions, is that pre-compressing at increasing overconsolidation ratios or pre-soaking the crushed material at constant and elevated stresses leads to the progressive vanishing of long-term deformations. 2013-06-04T17:48:04Z http://hdl.handle.net/2117/19443 Title: Gaudi and reinforced concrete in construction Authors: Grima Lopez, Rosa; Aguado de Cea, Antonio; Gómez Serrano, José Abstract: The first two decades of the 20th century witnessed the introduction and expansion of reinforced concrete as a building material in Spain. Few years passed between the introduction of the first patents in the most industrialized areas of the Iberian Peninsula and the subsequent generalization of the technique through scientific knowledge obtained in universities. This period coincides almost completely with the professional career of Antoni Gaudí, one of the most famous Catalan architects. This study reports that Gaudí had contact with this new material and discusses the transition he made from the traditional construction methods to the use of reinforced concrete in his later works. Placing the starting point in the relationship between Antonio Gaudí and the industrialists who built the first cement factories in Catalonia (especially Eusebi Güell), the research on the patents to which he had access are presented and the characteristics of his works with reinforced structures and materials are described. 2013-05-29T08:40:07Z http://hdl.handle.net/2117/19441 Title: Evolution of the formwork used in the temple of the Sagrada Familia Authors: Gómez Serrano, José; Espel, R; Grima, R; Burry, Mc; Aguado de Cea, Antonio Abstract: The Sagrada Família is Gaudi's unfinished work, to which he exclusively dedicated his last years of life. Even though he only got to build a small part of the total, he defined the rest through models and photographs. Gaudi's design for the inside of the Temple was based on a new geometric architecture that made extensive use of ruled surfaces (paraboloids, hyperboloids, ellipsoids), opening a new field which later architects have followed. The following article aims at showing the construction complexity of these structures, especially in relation to the set-up of their formwork. The vaults, which cover the naves at 30, 45, and 60 m heights, will be discussed. This discussion will show how the construction method, and in consequence the formwork, is adapted to the construction needs according to the geometric shape, size, position, material, and repetitions of each vault. 2013-05-29T08:29:09Z