Uso de modelos moleculares para ilustrar la arquitectura interna de los materiales de construcción

[SPA] Este trabajo muestra las relaciones existentes entre determinadas propiedades de los materiales de construcción y su arquitectura molecular. Se analiza primero la forma de moléculas sencillas y, a continuación, se muestran estructuras más complejas como cadenas lineales o ciclos moleculares. El trabajo hace mayor énfasis en los materiales plásticos, cerámicos y metálicos, pues algunas de sus propiedades se deducen fácilmente usando modelos moleculares. Los modelos se pueden adaptar a casos particulares y permiten profundizar en el conocimiento fundamental de materiales para arquitectura y edificación. [ENG] This paper provides connections between the observed macroscopic properties of building materials and their structure at a molecular level. First, basic structures are built using 'molecular building models' to show the simplest molecular geometries. After this, more complex structures as molecular chains or cyclic molecules are also analyzed. Additional emphasis is made on plastic, ceramic and metallic materials since their properties can be explained in a simple way by examining the molecular models. The molecular models can be easily adapted to case studies and they may be useful to improve our fundamental knowledge of architectural and building materials

Effect of the expanded perlite dose on the fire performance of gypsum plasters

Gypsum plasters are often used in buildings to provide passive protection against fire. This paper studies the fire behaviour of lightweight plasters containing moderate and high doses of expanded perlite. A propane flame was used to study the heat transmission through the plaster from the exposed side to the back side (2 cm thickness) using an IR camera. The microstructural and mineralogical variations induced by fire were analysed by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) using micro-perforated lids to improve the resolution (separation) of endothermic peaks of gypsum and bassanite. The exposed side of the plasters was drastically affected by fire regardless the concentration of perlite. However, important differences were found in the non-exposed side depending on the used amount of perlite. The greatest alteration was observed for high doses of perlite (6.5 % w/w) followed by control samples (0 % w/w). By contrast, using moderate doses of perlite (2.0 % w/w) the plasters showed excellent fire performance and CaSO4 2H2O was well preserved. The results suggest that the incorporation of lightweight materials to plasters should be carefully adjusted to ensure appropriate fire protection.The support given by the Technical University of Cartagena, UPCT is greatly appreciated (Ref: 3005216651; D023-09: Advanced mortars for building and architectural restoration). The authors want also to express their gratitude to Vicente Muñoz and Alberto Alcolea from SAIT laboratory at UPCT, who help us to overcome practical limitations of thermal analysis

Use of eggshell waste: A green and effective method for the synthesis of pure calcium hydroxide suspensions

This paper presents a rapid method to obtain pure suspensions of Ca(OH)2 dispersed in 2-propanol. To this aim eggshell wastes (CaCO3) were decarbonated to calcium oxide (CaO) followed by sonication-assisted hydrolysis in water/2-propanol to form calcium hydroxide (Ca(OH)2). An important advantage of the method is that it does not require chemical reagents due to the high purity of eggshell in CaCO3. Moreover, CaO is fully converted into Ca(OH)2 which means that purification steps are not needed, as occurs in conventional routes of synthesis. To assess the reliability of the synthetic procedure, the purity and amount of Ca(OH)2 were studied by X-ray diffraction (XRD), infrared spectroscopy (FTIR) and thermal analysis (TG). In addition, the morphology and crystallite size were examined by transmission electron microscopy (TEM) and X-ray diffraction (XRD) using Rietveld refinement method. It was found that sonicated Ca(OH)2 suspensions (5 g/L) were composed of particles that ranged in size from several nanometers to few micrometers. Finally, the suitability of Ca(OH)2 from eggshell to reinforce architectural stone was also studied by microscopy examination, colour change tests, surface hardness and surface erosion measurements. All tests confirmed the consolidation effectiveness was comparable to conventional nanolime treatments and surface erosion was visibly reduced

Use of image analysis to evaluate surface dispersion and covering performance of nanolime coatings sprayed on heritage material substrates

Coatings are often used to reinforce the surface of monuments, although little is known about their surface dispersion and effectiveness. This paper examines the surface distribution of Ca(OH)2 nanoparticle-based coatings (Ca(OH)2-NP). The coatings were sprayed on different substrates and studied by image analysis software and microscopy. Using image segmentation techniques the phase of interest (coating) was separated from the background material and evaluated. In control surfaces, up to 92.73% of the examined area was coated by the nanoparticles. In contrast, when the treatment was sprayed on building materials the NP-coatings were preferentially deposited in weaker zones, such as cracks or defects of the surface. In this case, the processed images revealed that less than 30% of the examined surface was coated by the NP-coating

Metodología del aprendizaje: ¿una asignatura necesaria?

[SPA]Esta comunicación presenta una iniciativa docente de la Escuela de Arquitectura e Ingeniería de Edificación. Una iniciativa a gran escala, pues, más allá de seminarios docentes o talleres específicos, se plantea en el primer curso de Ingeniería de Edificación una asignatura obligatoria de 3 créditos ECTS cuyo objetivo declarado es el alumno1 competente. Se parte de la idea de que, en general, el alumno viene del bachiller sin conocer el proceso de Bolonia y con ciertos hábitos de estudio basados, fundamentalmente, en la memoria. Por ello, esta asignatura ofrece la oportunidad de explicitar los que el alumno suele sobrellevar en solitario: su estilo de aprendizaje y su enfoque superficial o profundo al afrontar el estudio. Para que el alumno aplique, una vez conocido, cada aspecto de un aprendizaje significativo la asignatura se articula en torno a dos ciclos. Un ciclo corto donde la teoría se presenta, desarrolla y resume trufada de ejercicios y un ciclo largo en el que se utiliza un caso de contenido suficientemente complejo y de interés profesional para que sirva de laboratorio del estudio ajustado al estilo del alumno, significativo y profundo. Se aplica, también una estructura explicita de alineamiento entre objetivos y evaluación. [ENG]This paper presents an educational initiative of the School of Architecture and Building Engineering. A major initiative is therefore beyond specific training seminars or workshops, is raised in the first year of Building Engineering a compulsory course of 3 ECTS whose stated goal is the competent student. It starts from the idea that, in general, students coming from high school without knowing the Bologna process and study habits based primarily on memory. Therefore, this course offers the opportunity to show what students cope by yourself: your learning style and approach in dealing with superficial or deep study. For students to apply, once known, every aspect of meaningful learning the subject is structured around two cycles: A short course where the theory is presented, developed and resume riddled with exercises. And a long cycle in which case you use a sufficiently complex content and professional interest to serve as a laboratory study. It applies, also an explicit structure alignment between objectives and assessment.Metodología del AprendizajeEscuela de Arquitectura e Ingeniería de Edificació

Data on natural radionuclide's activity concentration of cement-based materials

Cement based materials may contain varying levels of radionuclides, mainly 226Ra (from the 238U series), 232Th and 40K, which are used to determine the Activity Concentration Index ("ACI"). According to the European directive Euratom 2013/59 in these materials, the “ACI” must be < 1 to be suitable for their use in construction. In this paper, data on the activity concentration of natural radionuclides in cement-based materials (i.e. cements, additions, pigments and aggregates) as well as their chemical composition are presented. Radioactivity measurements have been determined by using gamma spectroscopy the chemical compositions have been determined by X-Ray Fluorescence. Data for cements measured shown that white cements present a lower concentration of activity than conventional CEM I. In addition, the CAC (Calcium aluminate cements) present high activity concentration in the 232Th series. Regarding additions, FA (Fly Ash) are those that present the highest concentration of activity in the 238U and 232Th series, while olive biomass ashes are those supplementary cementitious materials that show the highest concentration of activity for 40K. Some pigments used in mortar and concrete technology were also characterized. Granitic and volcanic rocks, potentially used as aggregates present much higher activity concentration than the siliceous aggregate.This study was funded by the Spanish Ministry of the Economy, Industry and Competitiveness under project BIA2016-77252-P. Dr. M.M. Alonso also wishes to thank CSIC for funding the project PIE 2018 60I 054 (Proyecto Intramural de Incorporación)

Morteros de revestimiento monocapa : composiciones aligeradas y efecto de los hidrofugantes en la absorción de agua y la degradación del mortero / Marcos Lanzón Torres; director, Pedro Antonio García Ruiz.

Tesis-Universidad de Murcia.Consulte la tesis en: BCA. GENERAL. ARCHIVO UNIVERSITARIO. T.M. 3759

Materiales de construcción. Video

Reproducir ensayos de laboratorio que permitan una mejor comprensión de los conceptos de carbonatación y segregación en morteros y hormigones

Materiales de construcción: Estrategias para su enseñanza en las escuelas de arquitectura

Construction materials is a fundamental part of teaching at Architecture Bachelor’s degree. Material selection for the design and construction of facilities is based not only on aesthetic considerations but also on technical performance. Together, these impacts compromise a measure of the correct material selection. So, from the point of view of teaching construction materials there are several strategies that can be used, such as the complementation of the theoretical contents with laboratory practices, the organization of workshops and seminars or the creation of a materials library.La enseñanza de los materiales de construcción desempeña un rol fundamental en los estudios universitarios de arquitectura, pues tiene como finalidad proporcionar al futuro arquitecto la capacidad para la selección de materiales durante la realización del proyecto arquitectónico. En este sentido, los materiales son importantes por presentar una doble faceta, ya que si por un lado constituyen el elemento base para la construcción, por otro representan un aspecto clave en la definición del lenguaje arquitectónico. Así, centrando la atención en el punto de vista técnico, son diversas las estrategias docentes que sirven para aproximar al estudiante al conocimiento de los materiales de construcción, como la complementación de los contenidos teóricos con prácticas de laboratorio, la organización de talleres y seminarios o el montaje de una biblioteca de materiales

Caracterización químico-física de la piedra Tabaire y eficacia del tratamiento deconsolidación mediante hidróxido cálcico

La piedra Tabaire es una calcarenita extraída de las canteras romanas de Cartagena (España). Una parte importante del patrimonio arqueológico y arquitectónico de la ciudad se construyó total o parcialmente con este material. Algunos ejemplos son el Teatro Romano (S.I a.C.), la Muralla Púnica (S.III a.C.) o el Antiguo Hospital de Marina (S.XVIII), actual sede de la Universidad Politécnica de Cartagena. Antiguamente, el bloque de Tabaire era recubierto de yeso, cal o mortero con objeto de evitar su rápida degradación; en la actualidad, la piedra podría deteriorarse rápidamente debido a la ausencia de tales recubrimientos. El objetivo de este trabajo, consiste en realizar una caracterización químico-física del material e investigar un método de estabilización que sea limpio, seguro y permita una mejor conservación del Tabaire. Para la caracterización química se realizaron ensayos de Termogravimetría, Fluorescencia de rayos X y Difracción de rayos X. En la determinación de propiedades físicas se usaron ensayos no destructivos (esclerómetro Schmidt y ultrasonidos), así como ensayos mecánicos y de absorción capilar. Por último, se investigó un método de consolidación basado en saturar la piedra con suspensiones de hidróxido cálcico. Los resultados de caracterización indican que se trata de una roca rica en carbonato cálcico, que contiene calcita y/o dolomita e inclusiones de cuarzo. El material presenta una estructura muy porosa, así como baja resistencia mecánica y escasa dureza superficial. Debido a su porosidad, posee una elevada absorción de agua siendo, por tanto, más sensible a los agentes atmosféricos. La piedra Tabaire podría estabilizarse con suspensiones de hidróxido de calcio, cuya principal ventaja es la formación de depósitos de carbonato cálcico de naturaleza muy similar a la roca. Sin embargo, aunque el método estudiado proporciona ciertas mejoras, la elevada porosidad de la piedra dificulta el sellado de los poros limitando la eficacia del tratamiento