Fabricación de morteros de albañilería con escoria negra de horno eléctrico de arco EAF y escoria blanca de horno cuchara LF

La investigación que recoge la presente Tesis Doctoral desarrolla un estudio experimental para obtener morteros de albañilería utilizando como árido los residuos generados en la fabricación de acero en hornos eléctricos de arco, escoria negra EAF y escoria blanca LF, de manera conjunta. El objetivo es diseñar un “mortero seco industrial”, de consistencia plástica y una resistencia de, como mínimo, 5 N/mm2. Para conseguirlo se parte de una dosificación en peso de sus componentes 1/6 (1 parte de cemento y 6 partes de árido), y se consideran diferentes posibilidades de sustitución del árido natural por árido siderúrgico (25%, 50%, 75% y 100%), empleando además aditivos comerciales en las mezclas. Se realiza un estudio comparativo de las propiedades más significativas de los morteros, tales como la trabajabilidad, permeabilidad, adherencia y resistencias mecánicas, entre aquellos elaborados con áridos naturales y los fabricados con escorias. Una vez diseñados los morteros, se procede a estudiar los efectos del envejecimiento acelerado en los mismos. Se analiza la durabilidad y comportamiento frente a ciclos hielo-deshielo, humedad-sequedad, ambiente marino, cristalización de sales y atmósferas industriales. Los resultados indican que se pueden obtener morteros técnicamente viables para su uso en construcción y edificación, y de esta manera lograr una reutilización y puesta en valor de unos residuos que, de otro modo se destinarían a vertedero

Cualificación en los Objetivos establecidos en la Agenda 2030 de estudiantes y profesores en el Máster Universitario en Profesor de Educación Secundaria Obligatoria y Bachillerato, Formación Profesional y Enseñanza de Idiomas (MUPES)

Memoria ID2022-157 Ayudas de la Universidad de Salamanca para la innovación docente, curso 2022-2023

Properties of Gypsum Mortars Dosed with LFS for Use in the Design of Prefabricated Blocks

The aim of the present investigation is to determine the suitability of gypsum mortars with mineral additions of ladle furnace slags (LFS) for use in the manufacture of prefabricated blocks. Different dosages of gypsum mortars are designed, and the corresponding tests for their characterization are performed, with the objective of determining their properties, in both the fresh and the hardened state, in accordance with applicable standards. A suitable dosage is then chosen, bearing in mind the optimization criterion on the use of waste in gypsum mixtures, seeking a balance between the quantity of slag that is used and the quality of its properties. Completing the study, a series of complementary tests are performed related to its behaviour in the presence of heat, fire, and both thermal and acoustic transmission. The results showed that the gypsum mortar designs presented similar properties to the conventional mortars and can be approved for use in construction, either as gypsum mortars or as raw material for the manufacture of prefabricated blocks, in compliance with the requirements established in current European standards. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd

Declaration of performance (DOP) and CE marking of cement mortars made with recycled steel waste = Declaración de prestaciones y marcado CE de morteros de cemento fabricados con residuos de acería valorizados

The process of preparing a “Declaration of Performance” is presented for a masonry mortar manufactured with by-products from the steelmaking industry recycled as aggregates, for subsequent CE Marking, with the aim of promoting its commercialization within the European Union. Specific tests are applicable to construction mortars, both for masonry and rendering and plastering, for the verification of their performance, in accordance with harmonized standards EN-998-1 and EN 998-2. The study likewise sets out the Systems of Assessment and Verification of Constancy of Performance (SAVCP): System 4 for Rendering and Plastering Mortars and Systems 4 and 2+ for Masonry Mortars. Special importance in the new procedures for CE Marking is placed on the manufacturers, as they assume responsibility both for determining the properties of the materials and for establishing a control process in the factory. This document describes the technical development of the tests, in accordance with the applicable harmonized standards, for verifying the performance of the mortars designed with steelmaking slags as aggregates. The study concludes with the presentation of a Technical Data Sheet for the preparation of the corresponding CE marking for these new designed mortars.ResumenEste trabajo recoge el proceso de elaboración de una “Declaración de Prestaciones” de un mortero de albañilería fabricado a partir de residuos de acería valorizados como áridos, para su posterior Marcado CE, con el objetivo de facilitar su comercialización en la Unión Europea. Los morteros para construcción, tanto de albañilería como de revoco y enlucido, disponen de ensayos específicos para verificar sus prestaciones, de acuerdo con las normas armonizadas EN 998-1 y EN 998-2. De igual forma, se establece que los Sistemas de Evaluación y Verificación de la Constancia de las Prestaciones (EVCP) serán el Sistema 4 para los Morteros de Revoco y Enlucido, y los Sistemas 4 y 2+ para los Morteros de Albañilería. Los nuevos procedimientos para el Marcado CE en productos de construcción otorgan especial importancia a los fabricantes, ya que son los responsables de determinar las propiedades de los materiales, así como de establecer un proceso de control en fabrica. En este trabajo se describe el desarrollo técnico de los ensayos realizados para verificar las prestaciones de los morteros diseñados con áridos siderúrgicos. El trabajo concluye con la elaboración de la Ficha Técnica de Características para la elaboración del correspondiente distintivo de Marcado CE de los morteros diseñados

Mechanical behavior of a composite lightweight slab, consisting of a laminated wooden joist and ecological mortar

The investigation reported in this paper is an evaluation of the mechanical behavior of full-scale ecological mortar slabs manufactured with a mixture of expanded clay and recycled concrete aggregates. The composite mortars form a compressive layer over laminated wooden joists to form a single construction unit. To do so, full-scale flexural tests are conducted of the composite laminated wood-ecological mortar slabs with different types of mortar designs: reference mortar (MR), lightweight mortar dosed with recycled concrete aggregates (MLC), and lightweight mortar dosed with recycled mixed aggregates (MLM). The test results showed that the mortar forming the compression layer and the laminated wooden joists worked in unison and withstood a higher maximum failure load under flexion than the failure load of the wooden joists in isolation. Moreover, the laboratory test results were compared with the simulated values of the theoretical model, generated in accordance with the technical specifications for structural calculations contained in the Spanish building code, and with the results calculated by a computer software package. From the analysis of the results of the calculation methods and the full-scale laboratory test results, it was concluded that the safety margin yielded by the calculations validated the use of those methods on this type of composite slab. In this way, a strong mixed wood-mortar slab was designed, contributing little dead-load to the building structure and its manufacture with recycled aggregate, also contributes to the circular economy of construction materials. © 2020 by the authors

Design of new materials for the protection of construction units of residential buildings against fire action

This work shows the experimental process followed for the design of mortars with a fire-resistant plaster-based mortar, dosed with black slag residues from EAF Electric Arc Furnace (Electric Arc Furnace), generated in the manufacturing process of steel in the Primary Metallurgy phase. EAF black slag residues are valued as mineral filler by joining the mixtures. Although it is necessary to strengthen the final results with a deeper study, the results obtained in this first phase of characterization indicate that the use of black slag EAF in plaster mortars as a mineral load could be a technically viable option for the design of conglomerate materials destined to form prefabricated pieces for the protection of areas of buildings with potential fire load risk. In this way, in addition to obtaining plaster conglomerates with good technical performance, we managed to take advantage of an industrial waste without a defined use, valuing it as a construction material . Mortars have been characterized, both fresh and hardened, following the standards of the European Regulations. Subsequently, the mortars have undergone a noncombustibility test to determine their behavior against fire. The results show that gypsum plaster and plaster mortars dosed with EAF steel slag mineral filler have good technical performance, both fresh and hardened. Similarly, a good behavior against fire is observed, not only because of the nature of the gypsum binder, but also because of the EAF black slag mineral load dosed in the mixtures

Study of the expansion of cement mortars manufactured with Ladle Furnace Slag LFS

Industrial by-products generated in the steel manufacturing are successfully used as raw materials in the production of construction materials. However, steel slags, due to their nature and composition, can cause undesirable side-effects in mortars and concretes. The reactive components of LFS and EAFS can affect the stability of the cement matrix. This situation may be prevented by an adequate pre-treatment of slag stabilization and a study of the possible reactions within its mineralogical components, to ensure the stability of the slag over time. In this work, an experimental process is shown to evaluate the behaviour of LFS under adverse environmental conditions when used as aggregates in the manufacture of cement mortars for masonry, such as the presence of humidity, high temperatures (80°C) and possible alkali-silica and alkali-silicate reactions. The results show an acceptable behaviour under normal environmental conditions (20°C). However, the formation crystalline acicular structures were observed under high temperatures (80°C) and in the presence of humidity, which degraded the internal structure of the mortars manufactured with LFS. Copyright: © 2019 CSIC. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) License

Design and study of prefabricated materials for use in the interior construction and energy rehabilitation of the built heritage

The research developed studies the design of gypsum mortars dosed with valued polyurethane (PU) foam residues, with the aim of obtaining environmentally friendly building materials with improved thermal properties. Based on previous laboratory studies, suitable dosages of plaster-based mortars have been designed, using A1 (E-35) and B1 (yg) plaster as a binder, together with polyurethane (PU) foam and water residues. The corresponding characterization tests have been carried out, both in the fresh and hardened state, following the standards determined by the European Regulation of application. The results show that plaster-based mortars have good technical performance, similar to those of standard reference mortars. On the other hand, some thermal properties of mortars designed to know their behavior as insulating material have been studied. The Coefficients of Thermal Conductivity, Thermal Effusivity and Thermal Diffusivity have been studied. The results obtained allow us to affirm that the designed gypsum-based conglomerates show a good thermal behavior, retain heat and emit it to the environment slowly, which allows obtaining more efficient walls from the point of view of thermal comfort and the habitability conditions of buildings. Although more specific complementary studies have to be done, the first results show that the use of polyurethane (PU) foam residues in the design of plaster mortars can be a competitive advantage as an environmentally efficient construction material

Design and Characterization of Gypsum Mortars Dosed with Polyurethane Foam Waste PFW

The properties and the behaviour of plaster mortars designed with Polyurethane FoamWaste (PFW) are studied in this investigation. A characterization of the mixtures is completed, in accordance with the technical specifications of European Norms. The incorporation of polyurethane waste foam can yield porous and lighter mortars, with better resistance to water-vapour permeability, although with weaker mechanical strength and higher levels of absorbency. Nevertheless, suitable mechanical strengths were achieved, resulting in a new material that is compliant with the requirements of the construction industry. The use of PFW in the the manufacture of gypsum mortars for construction reduces the consumption of natural resources and, at the same time, recovers an industrial waste that is otherwise difficult to recycle. © 2020 by the authors