http://hdl.handle.net/10366/154697 Wed, 22 Apr 2026 02:18:55 GMT 2026-04-22T02:18:55Z http://hdl.handle.net/10366/170904 [EN] In the energy efficiency restoration, one of the most important aspects to consider is the loss of heat through the enclosing walls, for which constructive solutions are sought to improve their thermal performance, being usual to place a sheet of insulating material on the inner side of the facade, avoiding intervening on the outside, so as not to alter the appearance of the buildings. This fact is aggravated in the buildings built with brick factory, especially in those belonging to the Historical Heritage whose walls are raised with handmade bricks joined by mortar joints. This type of wall has a high porosity, whose immediate consequence is the absorption of a large amount of water, which is a good conductor of heat, which means that a wall saturated with water has a higher thermal conductance than being dry, increasing the consumption of energy needed to thermally condition the interior. Applying the current regulations, in order to determine the thermal conductivity of the mentioned walls, laboratory tests have been carried out on dry and saturated specimens and also on similar materials. The analytical study of the values obtained from the thermal conductance of the brick factory wall in wet state and in dry state offers data with important variations. The most immediate conclusions are two, firstly that it is necessary to know the state of humidity of the facades to determine the insulating behavior of the same and that to save energy and achieve an effective intervention, it is necessary to act on the outside of the walls, keeping it dry by applying treatments on the facades.; [ES] En la restauración de la eficiencia energética, uno de los aspectos más importantes a considerar es la pérdida de calor a través de los muros de cerramiento, para lo cual se buscan soluciones constructivas que mejoren su rendimiento térmico, siendo habitual colocar una lámina de material aislante en la cara interior de la fachada, evitando intervenir en el exterior, para no alterar la apariencia de los edificios. Este hecho se agrava en los edificios construidos con ladrillos prefabricados, especialmente en aquellos pertenecientes al Patrimonio Histórico, cuyos muros se levantan con ladrillos artesanales unidos con juntas de mortero. Este tipo de muro tiene una alta porosidad, cuya consecuencia inmediata es la absorción de una gran cantidad de agua, que es un buen conductor del calor, lo que significa que un muro saturado de agua tiene una conductancia térmica mayor que uno seco, aumentando el consumo de energía necesario para climatizar el interior. Aplicando la normativa vigente, para determinar la conductividad térmica de dichos muros, se han realizado ensayos de laboratorio en muestras secas y saturadas, así como en materiales similares. El estudio analítico de los valores obtenidos de la conductancia térmica del muro de la fábrica de ladrillos en estado húmedo y seco ofrece datos con variaciones importantes. Las conclusiones más inmediatas son dos: primero, que es necesario conocer el estado de humedad de las fachadas para determinar su comportamiento aislante; y segundo, que para ahorrar energía y lograr una intervención eficaz, es necesario actuar en el exterior de los muros, manteniéndolos secos mediante la aplicación de tratamientos en las fachadas. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10366/170904 2019-01-01T00:00:00Z http://hdl.handle.net/10366/170903 [ES] A principios del siglo XX, el sistema de fabricación de ladrillos en Zamora dio un giro hacia la modernidad con la instalación de la tejería mecánica San Antonio, en El Perdigón, desplazando a la elaboración artesanal que hasta entonces había sido el único sistema de producción. Esta tejería abastecía de ladrillos finos y extrusionados de gran calidad a la capital y a los municipios limítrofes, convirtiéndose en el material constructivo por excelencia en décadas, siendo fundamental conocer sus características para la conservación de los inmuebles.; [EN] At the beginning of the 20th century, brickmaking in Zamora underwent a transformation with the installation of the San Antonio mechanical brickworks in El Perdigón, replacing the artisanal production methods that had previously been the sole means of production. This factory supplied the city and surrounding municipalities with high-quality, thin, extruded bricks, making them the preferred building material for decades. Understanding their characteristics is essential for the preservation of buildings. Sat, 01 Jan 2022 00:00:00 GMT http://hdl.handle.net/10366/170903 2022-01-01T00:00:00Z http://hdl.handle.net/10366/170900 [EN] It is very common that the energy refurbishment of buildings of Cultural Heritage is undertaken without considering that their materials and the methods of construction are different from those of modern buildings. Therefore, when seeking the most efficient and effective solutions from an energy point of view, the first step is to understand the thermal characteristics of the materials with which these buildings were constructed. Likewise, as part of this heritage, the fact that many such buildings were constructed using uncoated bricks and with rich voluminous ornamentation or murals must be taken into consideration. This prevents the use of normal construction solutions which consist of attaching a layer of insulating material to the interior or exterior. In addition, the rich surface ornamentation of the walls is not conducive to carrying out tests in situ, so other procedures are needed to determine the thermal behaviour of the facade and thus be able to determine the most appropriate processes for their conservation. To this end, various heat flow tests have been carried out on brick masonry specimens that have characteristics similar to those of the walls of such buildings. This allows an abacus of the approximate thermal conductivity of such brick masonry to be produced with respect to the density of the brick and the moisture content of the wall. The values ​​of this abacus will serve as a reference to guide the energy refurbishment work to be performed on these buildings.; [ES] Es muy común que la rehabilitación energética de edificios del Patrimonio Cultural se lleve a cabo sin tener en cuenta que sus materiales y métodos de construcción difieren de los de los edificios modernos. Por lo tanto, al buscar las soluciones más eficientes y efectivas desde el punto de vista energético, el primer paso es comprender las características térmicas de los materiales con los que se construyeron estos edificios. Asimismo, como parte de este patrimonio, debe considerarse que muchos de estos edificios se construyeron con ladrillos sin revestimiento y con una rica ornamentación o murales. Esto impide el uso de soluciones constructivas convencionales, que consisten en la colocación de una capa de material aislante en el interior o el exterior. Además, la rica ornamentación superficial de las paredes dificulta la realización de ensayos in situ, por lo que se necesitan otros procedimientos para determinar el comportamiento térmico de la fachada y, así, poder determinar los procesos más adecuados para su conservación. Con este fin, se han realizado diversos ensayos de flujo de calor en muestras de mampostería de ladrillo con características similares a las de las paredes de dichos edificios. Esto permite elaborar un ábaco de la conductividad térmica aproximada de este tipo de mampostería de ladrillo en función de la densidad del ladrillo y el contenido de humedad del muro. Los valores de este ábaco servirán de referencia para orientar las obras de rehabilitación energética que se llevarán a cabo en estos edificios. Sat, 01 Jan 2022 00:00:00 GMT http://hdl.handle.net/10366/170900 2022-01-01T00:00:00Z http://hdl.handle.net/10366/170898 [EN] Brick masonry walls in Cultural Heritage buildings often have problems caused by rising damp. One solution is to coat the walls with repair mortars, including macroporous mortars. Their function is to ensure that the wall has a lower moisture content than without the coating to reduce deterioration, prevent efflorescence and prevent damp stains. This article presents the conclusions reached on the behaviour of macroporous mortars with regard to water absorption by capillary action and the drying process, by means of laboratory tests carried out on brick and mortar specimens of a similar composition to the old walls, coated with macroporous mortars. From the study it can be concluded that these coatings can help to maintain a lower level of humidity in the masonry before reaching saturation.; [ES] Los muros de ladrillo en edificios del Patrimonio Cultural suelen presentar problemas causados ​​por la humedad ascendente. Una solución consiste en revestir los muros con morteros de reparación, incluidos los morteros macroporosos. Su función es garantizar que el muro tenga un menor contenido de humedad que sin el revestimiento, reduciendo así el deterioro, previniendo la eflorescencia y las manchas de humedad. Este artículo presenta las conclusiones alcanzadas sobre el comportamiento de los morteros macroporosos con respecto a la absorción de agua por capilaridad y el proceso de secado, mediante ensayos de laboratorio realizados en muestras de ladrillo y mortero de composición similar a la de los muros antiguos, revestidas con morteros macroporosos. Del estudio se concluye que estos revestimientos pueden ayudar a mantener un nivel de humedad más bajo en la mampostería antes de alcanzar la saturación. Fri, 29 Nov 2024 00:00:00 GMT http://hdl.handle.net/10366/170898 2024-11-29T00:00:00Z http://hdl.handle.net/10366/163712 The large waste volumes globally generated have increased environmental awareness, promoting waste recycling as a sustainable construction material. This study presents a review of researches that analyze the thermal behavior of eco-friendly clay bricks incorporating organic and mineral waste materials as an addition. Many of these works also provide data related to the composition of the material, and its physical, micro-structural and mechanical characteristics. Most of eco-friendly clay units increase the porosity of the ceramic, improving the energy efficiency of masonry enclosures, reducing the clay content and the energy consumption during the fire process. The positive effects of lightweight ceramics are an opportunity to improve the fire resistance inside green buildings. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10366/163712 2019-01-01T00:00:00Z http://hdl.handle.net/10366/162104 [EN] Spent diatomaceous earth, a by-product of wine filtration, holds significant prom-ise for use in concrete mixtures due to its pozzolanic properties, which enhanceconcrete performance. This research explores the application of spent calcineddiatomaceous earth (SCDE), heat-treated at 700 C to remove organic content, as apartial substitute for cement or sand in concrete. The high silica content of SCDEcontributes to the formation of additional calcium silicate hydrates during thehydration process, leading to improvements in mechanical strength over time.The study includes a preliminary analysis of cement replacements ranging from5% to 10% and sand replacements from 2.5% to 15%, assessing their effects onworkability, density, water absorption, and compressive strength at 7 and 28 days.The testing program focuses on three key compositions: the reference concreteand optimal mixtures with 10% cement and 5% sand replacements. Compressivestrength tests are conducted at 7, 28, 90, 180, and 360 days. The results, validatedthrough ANOVA, demonstrate the influence of SCDE on concrete strength overtime, with distinctive behavior patterns identified for different mixtures. Thestrength of concrete with replacements correlates with the reference strength,with a multiplicative factor that varies from 7 to 90 days and then. When SCDEreplaces cement, the factor is less than one before 28 days due to the slow pozzola-nic reaction, whereas for sand replacement, it always exceeds one because of theinitial filler effect. After 90 days, the strength multiplicative factors are 1.13 forcement replacement and 1.30 for sand replacement, demonstrating the potentialof SCDE for sustainable concrete manufacturing and its positive long-term impacton mechanical performance. Wed, 18 Dec 2024 00:00:00 GMT http://hdl.handle.net/10366/162104 2024-12-18T00:00:00Z http://hdl.handle.net/10366/155347 [ES] Este trabajo presenta el diseño para la rigidización, mediante barras de acero encoladas, de un nudo de esquina de un caso real de pórtico triarticulado de madera. Para realizar el estudio, se desarrollaron varios modelos paramétricos de elementos finitos de la zona que permitieran englobar todas las posibilidades. Del análisis de los resultados, se concluye la necesidad de la colocación de las barras, más concretamente de las exteriores, cuando se quiere que el nudo sea capaz de transmitir grandes solicitaciones sin superar los límites admisibles de la madera. Las barras transversales son necesarias para absorber los altos valores de tensiones tangenciales en la frontera pilar-dintel y de las tensiones perpendiculares a la fibra. Las barras interiores no parecen tener un papel tan importante, ya que la mayor parte del esfuerzo de compresión se transmite por contacto entre las superficies de la madera. Mon, 27 Sep 2010 00:00:00 GMT http://hdl.handle.net/10366/155347 2010-09-27T00:00:00Z http://hdl.handle.net/10366/155345 [EN] This paper reports a finite-element-based study of the reduction, using glued-in rods, of the perpendicular-to-grain stresses in the apex zone of curved beams in glulam structural timber members. Currently, the design of this type of elements is conducted using simplifying assumptions about the perpendicular-to-grain stress distribution in the apex zone, which start out from the calculation of the parallel-to-grain stress distribution and apply some corrector coefficients to it, confirmed by years of experience and studies. This work presents a practical approach, by conducting a numerical simulation of the behavior of these stresses in the apex zone with the presence of glued-in rods, which enables optimization in the design of this type of assembly. The finite element results demonstrate the importance of the features, number and positions of the glued-in rods. Wed, 13 May 2009 00:00:00 GMT http://hdl.handle.net/10366/155345 2009-05-13T00:00:00Z http://hdl.handle.net/10366/155344 [ES] La madera es un material estructural anisotrópico, cuya resistencia a la tracción en la dirección perpendicular a la fibra es muy inferior en valor al resto de sus características resistentes. En aquellas configuraciones donde aparece este esfuerzo, como por ejemplo las vigas entalladas en los apoyos, el comportamiento del elemento estructural puede quedar seriamente comprometido. En tales casos es necesario plantear soluciones de refuerzo, siendo una posibilidad el empleo de pernos. En este trabajo se realiza un estudio mediante elementos finitos de la reducción de tensiones que se puede obtener al aplicar esta solución, analizando la influencia de los parámetros más significativos: profundidad de la entalladura, posición del perno y fuerza de apriete. Thu, 15 Jan 2009 00:00:00 GMT http://hdl.handle.net/10366/155344 2009-01-15T00:00:00Z http://hdl.handle.net/10366/155340 [ES] Este trabajo presenta un estudio de las tensiones que aparecen en una unión de tres barras, de una cercha ligera de madera, realizada con placas-clavo. El objetivo fue determinar el efecto de las variables más significativas, como el porcentaje de esfuerzo transmitido por contacto directo entre piezas que trabajan a compresión, el espesor de la placa, el nivel de cargas y el diseño de la unión. Para realizar el estudio, se desarrollaron modelos paramétricos de elementos finitos de la unión. Del análisis de los resultados, se concluye que existe un valor de la holgura entre piezas a partir del cual el contacto aparece, y otro por debajo del cual el porcentaje de la contribución de la transmisión de esfuerzo por contacto se estabiliza. También se observa que estos valores no se ven afectados por el espesor de la placa o el diseño de la unión. Fri, 22 May 2009 00:00:00 GMT http://hdl.handle.net/10366/155340 2009-05-22T00:00:00Z http://hdl.handle.net/10366/155338 [EN] The EC-5 is the European Structural Standard which develops the design of timber structures. One of its principal aims is to give the engineers the rules to design the connections that are used in these kind of structures. Dowel-type fasteners are one of the most extended kind of joints that can appear, and they work in single or in double shear. The focus of this research is to study the design stresses in this last case. The results obtained using the rules included in the official standard will be compared with those arising from the finite element method. The interaction between stresses and other variables such as geometry, section and material will be presented, as well as an analysis of the results. Thu, 11 Jun 2009 00:00:00 GMT http://hdl.handle.net/10366/155338 2009-06-11T00:00:00Z http://hdl.handle.net/10366/155246 [EN] This paper studies the shear stresses appearing in the contact zones of dowel-type joints of timber structures using expansive kits. To achieve this goal, a finite element model capable of determining the effect of using these kits on the global response of the joint has been prepared. For its development, different tools have been used to model the expansion process, the contact between the different parts of the joint, the compression pressures triggered by this contact, the resulting shear stresses caused by friction and, finally, the effect of all these circumstances on the overall performance of the joint, especially on the relationship between the applied load and the related displacement. The design of the model has been checked for correctness using experimental tests. The results obtained show that the use of expansive kits slightly improves the load-carrying capacity of the dowel through the rope effect. Sun, 15 Jan 2017 00:00:00 GMT http://hdl.handle.net/10366/155246 2017-01-15T00:00:00Z http://hdl.handle.net/10366/155245 [EN] This work is devoted to the development of a calculation proposal for dowel-type joints in timber structures that takes into account the increase in load capacity due to the use of threaded dowels. While the method is based on acknowledged criteria of structural standards, it also considers the crushed areas that appear in the timber near the zone of contact with the dowel’s thread. Thereby, it comes closer to the actual mechanical behaviour of the whole joint when it suffers a relative displacement between its different parts under an external load. The equations proposed in this study to define the load capacity of the joint take into account the rope effect produced by the axial forces arising on the dowel due to the combined effect of bending of the dowel and compression of the timber fibres embedded in its thread. A comparison of the results of the new analytical method proposed with those of a battery of experimental tests is shown. Thu, 11 Aug 2016 00:00:00 GMT http://hdl.handle.net/10366/155245 2016-08-11T00:00:00Z http://hdl.handle.net/10366/155233 [ES] Se presenta un estudio sobre las tecnologías de unión en nudos de estructuras de madera, centrándose sobre todo en aquellas de tipo perno encolado. Se buscó comparar el rendimiento de estas uniones con las de tipo clavija sin encolar y se compararon los resultados obtenidos por tres métodos: i) aplicando las ecuaciones analíticas contempladas en las normas oficiales y la literatura; ii) realizando estudios mediante el método de los elementos finitos; iii) y realizando ensayos de laboratorio de estos mismos diseños propuestos. Para realizar el estudio por el método de los elementos finitos, se prepararon varios modelos paramétricos que permitieron englobar todas las variaciones posibles de las variables que afectan a la unión. Los resultados permitieron determinar como la modificación de las variables estudiadas afectan al rendimiento en cada caso.; [EN] A study is presented on knot-joining technologies for wooden structures, focusing especially on those of the glued bolt type. An attempt was made to compare the performance of these joints with those of the unglued pin type and the results obtained were compared by three methods: i) applying the analytical equations contemplated in the official standards and the literature; ii) carrying out studies using the finite element method; iii) and carrying out laboratory tests of these same proposed designs. To carry out the study using the finite element method, several parametric models were prepared that allowed all possible variations of the variables that affect the union to be included. The results allowed us to determine how the modification of the studied variables affects performance in each case. Mon, 27 Jun 2011 00:00:00 GMT http://hdl.handle.net/10366/155233 2011-06-27T00:00:00Z http://hdl.handle.net/10366/155232 [ES] El objetivo de este trabajo es definir los procedimientos de ensayo a seguir en uniones del tipo clavija para estructuras de madera, a fin de identificar su evolución resistiva en situaciones reales. Se desarrolla una metodología en consonancia con las nuevas directrices de la normativa europea, sobre probetas de tamaño real, reflejando los parámetros principales a tener en cuenta durante el ensayo y la evolución de gráficas tensión-deformación. Se contemplan factores como el aplastamiento de la madera, la flexión de la clavija y el efecto soga. Partiendo del análisis de prototipos, se fabrican herrajes específicos y varias series de probetas, para desarrollar ensayos sobre tres variantes. A saber, unión con bulón roscado, unión con pernos encolados y unión con arandela-tuerca, con el objetivo de analizar los comportamientos del nudo.; [EN] The objective of this work is to define the test procedures to follow in dowel-type joints for wooden structures, in order to identify their resistive evolution in real situations. A methodology is developed in line with the new guidelines of the European regulations, on real-size specimens, reflecting the main parameters to be taken into account during the test and the evolution of stress-strain graphs. Factors such as wood crushing, dowel bending and the rope effect are considered. Starting from the analysis of prototypes, specific fittings and several series of test tubes are manufactured, to develop tests on three variants. Namely, union with threaded bolt, union with glued bolts and union with washer-nut, with the aim of analyzing the behavior of the knot. Tue, 27 May 2014 00:00:00 GMT http://hdl.handle.net/10366/155232 2014-05-27T00:00:00Z