Japan Bridge. Peter Rice, París 1994

Guión para el desarrollo de la práctica de maquetas.Departamento de Construcciones Arquitectónicas, Ingeniería del Terreno y Mecánica de los Medios Continuos y Teoría de Estructura

Fabricación y ensayo de probetas de fábrica de ladrillo

Material docente elaborado a partir laboratorio realizado en la asignatura “Estructuras de Ladrillo” durante el curso académico 2018-19, se divide en dos sesiones prácticas: en una primera sesión los estudiantes, organizados en pequeños grupos, construyen con sus propias manos unas probetas de ladrillo. Para ello se les facilitan los materiales; ladrillos, mortero, agua, y herramientas. Transcurridos 28 días, en una segunda sesión, se ensayan a compresión las probetas de fábrica, estimando previamente cada grupo la resistencia “esperada” de sus probetas. Para realizar este ensayo, cada grupo es responsable de la instrumentación de su probeta, enseñándoles la base de la medición con bandas extensométricas, sus fundamentos teóricos y las técnicas de colocación.Departamento de Construcciones Arquitectónicas, Ingeniería del Terreno y Mecánica de los Medios Continuos y Teoría de Estructura

REHABEND 2016

Producción CientíficaEl objetivo principal de este trabajo es el perfeccionamiento del ensayo no destructivo de velocidad de propagación de ondas ultrasónicas sobre madera aserrada de coníferas de gran escuadría y uso estructural (MEG), y la interpretación de los resultados obtenidos. Para ello se han escogido dos especies de madera ampliamente utilizadas (Pinus sylvestris L. y Pinus radiata D. Don) y un aparato de ondas sónicas Fakopp Microsecondtimer©, por sus cualidades para emplearlo sobre estructuras construidas con acceso limitado. Por medio de la realización de ensayos en laboratorio sobre un abanico de ángulos conocidos, se ha estudiado la influencia que tiene el ángulo entre la dirección de la fibra y la de las ondas ultrasónicas al realizar ensayos indirectos; en la práctica los únicos posibles en la mayoría de estructuras en servicio. Se ha optimizado el postproceso analítico de resultados para la generación de un modelo de ajuste (ecuación general) en función del ángulo, obtenido por la regresión de datos reales medidos en laboratorio para las especies y el equipo empleado. Se determinan también los ángulos de aplicación más homogéneos y fiables para la realización de este tipo de ensayo indirecto en obra

Wood Density Determination by Drilling Chips Extraction in Ten Softwood and Hardwood Species

Producción CientíficaResearch Highlights: The novelty of this study is the development of an accurate wood density estimation method based on a relatively brand new semi-destructive testing technique (drilling chips extraction). This method is especially crucial in the assessment of existing timber structures. Background and Objectives: Probing, drilling, and coring are non-destructive and semi-destructive techniques commonly used for timber density estimation in existing timber structures. Most of these techniques show poor or medium accuracy or are so expensive or destructive. This paper aims to obtain accurate estimation models for wood density in existing structures using the easy to use drilling chips extraction technique. Materials and Methods: 300 specimens (95 × 65 × 200 mm3) from ten softwood and hardwood species covering a wide range of density (from 350 to 980 kg·m−3) were tested after conditioning. The Wood Extractor device based on the drilling chips extraction technique was used in the radial and the tangential direction. Mass of the chips collected (drilling residue) from each drill was recorded. Results: Density obtained from drilling residue was not statistically significantly different between radial and tangential directions avoiding take into account direction when measuring. The density obtained in the whole specimens is slightly higher than the density obtained by drilling residue being this difference uniformly through the range of densities studied. Two different estimation models were presented with high determination coefficients (96% and 97%) and low standard errors. These results were similar to those obtained by other authors using core drilling but causing less damage. Conclusions: Drilling chips extractor is a simple, reliable and inexpensive method to estimate density in existing structures with accuracy.Ministerio de Economía, Industria y Competitividad (project BIA2014-55089-P)Asociación de Investigación Técnica de la Madera (projects AITIM-Fucovasa 2012–2013 and ITIM Fucovasa 2014–2015

Wood Density and Moisture Content Estimation by Drilling Chips Extraction Technique

Producción CientíficaThe novelty of this study is the development of an accurate wood moisture content (MC) estimation method based on a relatively brand-new, non-destructive testing technique (drilling chips extraction). The method is especially important in the assessment of existing timber structures, where non-destructive testing (NDT) results are affected by wood MC and should be adjusted to a reference MC, usually 12%. In the assessment of timber structures, it is not possible to determine MC by oven drying method and this should be estimated. Electrical resistance and capacitance are the conventional methods used for MC estimation. This research work aims to present an accurate MC estimation method based on the drilling chips extraction technique. For that, 99 specimens (90 × 65 × 38 mm3) from three softwood and hardwood species covering a wide range of densities (from 355 to 978 kg m−3) were tested after conditioning at five different MCs (5%, 10%, 15%, 20%, 25%). The Wood Extractor device based on the drilling chips extraction technique was used. The mass of the chips collected (drilling residue) from each drill was recorded. The results show that the MC of the chips extracted was statistically significantly different than the MC of the specimen and cannot be directly used as MC determination. However, the chips MC can be used as an estimator of specimen MC with high determination coefficients (R2 from 71% to 86%). As the main result, models to estimate density directly adjusted to a reference 12% MC from the wet and dry mass of chips extracted were developed with an R2 of 98%. In sum, the drilling chips extractor is a dependable and straightforward method to estimate MC and density from only one measurement. Density adjusted to a reference 12% MC can be directly estimated from a single model.Ministerio de Economía, Industria y Competitividad (project BIA2014-55089-P)Asociación de Investigación Técnica de la Madera (projects AITIM-Fucovasa 2012–2013 and AITIMFucovasa 2014–2015

GIS Framework for Rapid Seismic Loss Assessment: Case Study of Granada Metropolitan Area

Traditional vulnerability methodologies rely on collecting building data through time consuming surveys and visual screening. Geospatial infrastructure systems have rapidly evolved and today we can access massive geospatial data. Digital cadastral databases combine location, attributes, and temporal information for building stock. This paper proposes a GIS-based framework to estimate seismic vulnerability and losses from cadastral data only. The framework is rooted on wellknown displacement-based procedures and uses probabilistic models of the building structural capacity. A featured application to 287,503 housing units in metropolitan area of Granada is presented to showcase outputs for decisionmaking: performance displacement, damage level and repair cost.FEDER/Junta de Andalucía-Conserjería de Economía y Conocimiento, grant number B-TEP-306-UGR18Grant PID2020-120135RB-I00 funded by MCIN/AEI/ 10.13039/501100011033Ministry of Education for ‘Colaboración’ gran

Morphology and Material Composition of the Mouthparts of Stromatium unicolor Olivier 1795 (Coleoptera: Cerambycidae) for Bionic Application

The novelty of this study is the deep analysis of the morphologic, geometric and mechanical performance of longhorn beetle larvae mouthparts. Furthermore, a metal nano identification of jaw reinforced parts was made. Background and Objectives: Analysis of insect mechanical properties has shown an important application in the develop of bionic technologies such as new materials, industrial machines and structural concepts. This study aims to determine the mechanical and geometric properties of longhorn beetle (Stromatium unicolor Olivier 1795) larvae mouthparts to improve the development of innovative cutting tools. In addition, this study obtains a nano identification of metals in the cuticle of the mouthparts, which will enable the development of new nontoxic and sustainable preservation agents against xylophagous insects based on nanoparticles. Materials and Methods: five third-larval-stage samples of Stromatium unicolor were used to study its mandible morphologic, geometric and mechanical properties. To this end, mouthparts were analyzed by several microscopic techniques using a scanning electron microscope, a stereomicroscope and an optical microscope. Composition analysis was performed using with two Analytical-Inca X-ray detectors, dispersive energy spectroscopy and dispersive wavelength spectroscopy. Results: The main geometric parameters of the insect jaw are the edge angle (β = 77.3°), maximum path depth of the insect (120 μm), length (800 µm) and mouthpart movement, which were identified and measured. The chemical analysis results of the jaw tissues shows the presence of zinc and manganese. Conclusions: The geometry and angles of the mouthparts can be applied in the fabrication of bionic self-sharpening cutting tools. Molecular compounds that form the reinforcing elements in the jaws can be used to develop wood preservatives based on nanometals and metal absorption and metabolism inhibitor

Internal GFRP Reinforcement of Low-Grade Maritime Pine Duo Timber Beams

This paper presented an experimental structural-scale test campaign used to analyze the flexural behavior of low-grade maritime pine (Pinus pinaster Ait.) duo timber beams reinforced with an internal glass fiber-reinforced polymer (GFRP) sheet. For this purpose, thirty (30) unreinforced duo beams and thirty (30) duo beams internally reinforced with a unidirectional GFRP sheet with an areal mass of 1200 g/m2 were produced and tested. The addition of a low GFRP reinforcement ratio (1.07%) in the tension zone of the duo beams provided an average improvement of 8.37% in bending stiffness (EI) and an increase of up to 18.45% in ultimate moment capacity. In addition to this improved bending behavior, the internal GFRP reinforcements seemed to decrease the influence of wood singularities and wood heterogeneity on mechanical properties, which allowed for better characteristic values to be reached and for the achievement of results with less variability.Ministerio de Ciencia e Innovación (grant BIA2012-31233)Junta de Castilla y León (grant VA051A10-2

Internal reinforcement of laminated duo beams of low-grade timber with GFRP sheets

The purpose of this work is to study the flexural behaviour of Populus euroamericana I-214 low-grade glulam timber beams, internally reinforced with Glass Fibre Reinforced Polymer (GFRP). To this end, 30 unreinforced beams and 60 reinforced beams, with two ratios of GRFP reinforcement, were produced and tested. Results show an improvement in the flexural behaviour of reinforced beams, with noticeable increases in stiffness (MOE) and ultimate moment capacity (MOR). By using relatively low reinforcement ratios (1.07%, 1.6%) in the tension zone, we have measured an average improvement of 12.1% and 14.7% in stiffness, and an increase up to 23% in moment capacity. GFRP reinforced seems to reduce the influence of timber heterogeneity and singularities (knots, cracks . . .), which translates into less scattered results and better characteristic values.Ministerio de Ciencia e Innovación (project BIA2012-31233)Junta de Castilla y León (project VA051A10-2

Modelling of impact falling ball test response on solid and engineered wood flooring of two eucalyptus species

In this study, dynamic hardness tests on solid and engineered wood flooring specimens of Eucalyptus globulus Labill. and Eucalyptus grandis W. Hill ex Maiden hardwoods were performed because nowadays, these fast-growing hardwoods are still scarcely employed for this use. Furthermore, another two examples of hardwood commonly applied on wood flooring, Quercus robur L. and Hymenaea courbaril L., were also tested. To compare their properties, a dynamic impact hardness test based on the impact of steel balls, with several diameters, and drop heights was developed. Accordingly, 120 solid wood flooring specimens and 120 engineering wood flooring specimens were producing with these four hardwood species. Dynamic impact tests were made with three steel balls of different diameters (30–40–50 mm), and they were carried out from five different drop heights (0.60–0.75–0.90–1.05–1.20 m). The impact of the steel ball drew the size of the footprint on the surface and this mark was measured with a digital caliper for both dimensions, diameter and depth, as footprint diameter (FD) and indentation depth (ID). Data from 3000 samples, corresponding to 120 different individual groups (4 species × 3 ball diameters × 5 drop height × 2 floor type) were analyzed. Results indicated that the variability of ID (CV between 19.25–25.61%) is much greater than the values achieved for FD (CV between 6.72–7.91%). Regarding the fast-growing hardwood species tested, E. globulus showed a similar behavior to traditional hardwood applied on wood flooring in Europe, Q. robur, and it could be a promising growth in the flooring industry. However, E. grandis showed the worst values compared to traditional hardwood in all test configuration