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 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

Effect of temperature on geopolymer and Portland cement composites modified with Micro-encapsulated Phase Change materials

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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

Exposing Sustainable Mortars with Nanosilica, Zinc Stearate, and Ethyl Silicate Coating to Sulfuric Acid Attack

Obtaining durable materials that lengthen the service life of constructions and thereby contribute to sustainability requires research into products that improve the durability of cementitious materials under aggressive conditions. This paper studies the effects of sulfuric acid exposure on four mortar types (control mortar, mortar with nanosilica, mortar with zinc stearate, and mortar with an ethyl silicate coating), and evaluates which of them have better performance against the acid attack. After 28 days of curing, the samples were exposed to a sulfuric acid attack by immersing them in a 3% w/w of H2SO4 solution. Physical changes (mass loss, ultrasonic pulse velocity, open porosity, and water absorption), and mechanical changes (compressive strength) were determined after the sulfuric acid exposure. A scanning electron microscope (SEM) was used to characterize the morphology of the surface mortars after the exposure. The control mortar had the highest compressive strength after the acid attack, although of the four types, the zinc stearate mortar showed the lowest percentage of strength loss. The zinc stearate mortar had the lowest mass loss after the acid exposure; moreover, it had the lowest capillary water absorption coefficient (demonstrating its hydrophobic effect) both in a non-aggressive environment and acid attack.This research was funded by the University of Alicante (GRE13-03) and (VIGROB-256)

Effect of freeze-thaw cycles on the mechanical behavior of geopolymer concrete and Portland cement concrete containing micro-encapsulated phase change materials

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Physical and mechanical properties of fly ash and slag geopolymer concrete containing different types of micro-encapsulated phase change materials

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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