Browsing by Author "San-José, José T."
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Item Assessment of particle packing models for aggregate dosage design in limestone and EAFS aggregate-based concretes(2022-04-18) García-Cortés, Verónica; García Estévez, David; San-José, José T.; TRAZABILIDAD CIRCULARAn experimental method and two discrete Particle Packing Models are assessed for aggregate mix design. The aim is to model the most compacted structure of commercial natural limestone aggregate and electric steelmaking slag fractions. The experimental method is reliable and effective, although somewhat laborious. Regarding the discrete models, the Compressible Packing Model and the 3-Parameter Particle Packing Model showed high reliability when used to perform the most compact of both the ternary and the quaternary aggregate mixtures. Eight concrete mixes were manufactured to produce concretes of low and medium workability, containing the highest possible content by volume of coarse aggregate, and their resultant in-fresh properties, defined through slump and density, confirmed the validity of using the Particle Packing Models for each mix dosage under study.Item Comparison between experimental values and standards on natural stone masonry mechanical properties(2012-03) García, David; San-José, José T.; Garmendia, Leire; Larrinaga, Pello; TRAZABILIDAD CIRCULAR; Tecnalia Research & InnovationThe research presented in this paper investigates the mechanical properties under compressive loads of a natural stone masonry. Selected materials and arrangement are typical from the Romanesque period, the main architectural style in Europe from the 9th to the 13th centuries, found both in heritage and conventional buildings. The characterisation of the basic materials and different stone masonry prisms are included. Sandstone and low strength lime-cement mortar were used for this experimental work because of their availability and similarity with the masonry found in many historic buildings from the North of Spain. The morphological characteristics of the original ancient walls were also taken into account, in order to manufacture prism specimens that were as representative as possible of the Spanish Romanesque typology (i.e. in terms of its geometry, composition of the internal core, relative size, etc.). The experimental values were compared with the analytical ones provided by other author's equations, codes and main standards. The differences on the obtained results are analysed and the more suitable formulae are identified. The results permit a better understanding of these materials and a reliable source of data for the validation of the existing structures.Item Effect of high-alumina ladle furnace slag as cement substitution in masonry mortars(2016-10-01) Herrero, Tamara; Vegas, Iñigo J.; Santamaría, Amaia; San-José, José T.; Skaf, Marta; GENERALLadle furnace (white or basic) slag is a significant by-product of the steelmaking industry; nowadays the manufacturing process yields two types of basic slag that are either low or high in alumina. The present research focuses mainly on the composition of the high-alumina slag and the reactivity of its compounds such as calcium aluminates, free calcium oxide, and free magnesium oxide, when aged at room temperature and at water steam temperature (accelerated aging). Additionally, a characterization was performed of pastes and masonry mortars that incorporate high alumina ladle furnace slag as a supplementary cementing material in partial substitution of Portland cement in amounts of 10% and 20% by weight. Different properties are studied such as porosity distribution, volumetric stability, mechanical strength and durability, mainly referring to wetting-drying aging cycles. The study concludes that high-alumina ladle furnace slag can induce slight hydraulic reactivity and its partial addition has no negative effect on the fundamental properties of cement masonry mortars.Item Experimental and numerical modeling of basalt textile reinforced mortar behavior under uniaxial tensile stress(2014-03) Larrinaga, Pello; Chastre, Carlos; Biscaia, Hugo C.; San-José, José T.; Tecnalia Research & InnovationDuring the last years several projects and studies have improved the knowledge about textile reinforced mortar (TRM) technology. TRM has already been used in strengthening masonry and reinforced concrete structural elements such as walls, arches, columns and beams. This material is presented as a real alternative to the use of fiber-reinforced polymers (FRP) in situations where these composites have presented some drawbacks or their use is banned. Textile reinforced mortar show a complex mechanical behavior derived from the heterogeneity of the constituent materials. This paper aims to deepen the knowledge of this composite material in terms of tensile behavior.Following this scope, this paper presents an experimental campaign focused on thirty-one TRM specimens reinforced with four different reinforcing ratios. The results are analyzed and contrasted with two distinct models. (i) The Aveston-Cooper-Kelly theory (ACK) which is based on a tri-linear analytical approach; and (ii) a non-linear numerical simulation with a 3D finite element code.The finite element analysis (FEA) of the TRM tensile tests also showed no significant dependence on the basalt-to-mortar interface, i.e., the choice of a bond-slip curve in order to reproduce the bond stresses and slippages along the interface is irrelevant and it can be simply considered as rigid interface.Item Experimental study of traditional stone masonry under compressive load and comparison of results with design codes(2012-07) García, David; San-José, José T.; Garmendia, Leire; San-Mateos, Rosa; TRAZABILIDAD CIRCULAR; Tecnalia Research & Innovation; E&I SEGURAS Y RESILIENTESThis study addressed the mechanical behaviour of a natural stone masonry typical from the Spanish Romanesque, both in Heritage and conventional buildings. The objective of this research was to provide new data about the mechanical properties, especially the compressive strength values. The characterisation of the basic materials and different stone masonry prisms is presented. Sandstone and low strength lime-cement mortar were used for this experimental work, because of their availability and similarity with the masonry found in many historic buildings from the north of Spain. The morphological characteristics of the original ancient walls were also taken into account, in order to manufacture prism specimens that were as representative as possible of the Spanish Romanesque typology (i.e. in terms of its geometry, composition of the internal core, relative size, etc.). Additionally the experimental values were compared with the analytical ones provided by the main recommendations and standards. The analysis of the results permits a better understanding of these materials and a reliable source of data for the validation of the existing structures.Item Fiber-reinforcement and its effects on the mechanical properties of high-workability concretes manufactured with slag as aggregate and binder(2021-11) Ortega-López, Vanesa; García-Llona, Aratz; Revilla-Cuesta, Víctor; Santamaría, Amaia; San-José, José T.; Tecnalia Research & InnovationThe feasibility of manufacturing fiber-reinforced concretes of high workability through additions of high volumes of electric arc furnace steel slag is evaluated in this paper, using sustainable binders with ground granulated blast furnace slag and ladle furnace slag as a supplementary cementitious material. An extensive experimental plan is developed to test four (self-compacting and pumpable) concrete mixtures, some reinforced with 0.5% vol. of (metallic or synthetic) fibers, in both the fresh and the hardened state. Very specific mechanical aspects are examined, such as the evaluation of both longitudinal and transversal stress-strain compressive behavior, and the assessment of direct tensile strength through the “dog-bone” test. The results of testing this sustainable concrete design yielded suitable mechanical strengths, and good toughness, ductility and impact strength, among other properties. Good adhesion between the fibers and the cementitious matrix was also evident from the fiber pull-out test results. Finally, the overall results confirmed that the use of electric arc furnace steel slag can make a real contribution to construction-sector sustainability and that the mechanical behavior of these novel concretes meets the basic design requirements for use in real structures.Item Ideal dosage curves for limestone and EAFS aggregate concretes and their sustainability assessment(2024-02) García-Cortés, Verónica; García-Estévez, David; San-José, José T.; Egiluz, Ziortza; TRAZABILIDAD CIRCULARExperimental tests, and two conventional grading curves, are used to design a dosing scheme, seeking the best way to enhance the general sustainability of certain types of low-to-medium workability concrete mixes. The aim is to achieve highly compacted aggregate gradations, thereby minimizing the need for Portland cement consumption. Several aggregate mix designs, employing fractions of both commercial limestone and recycled electric steelmaking slag, were prepared and assessed. Nine concrete mixes of structural quality (above 40 MPa as compressive strength) were manufactured to analyze their aggregate packing density and their performance as engineering concrete mixtures. The results obtained after classical testing showed excellent quality homogeneous concrete mixes, considering both the in-fresh and in-hard properties. Subsequently, a sustainability analysis of all the mixes led to the conclusion that they were of low environmental impact, due to their high aggregate content and their low cement consumption which, additionally, included other industrial co-products with hydraulic properties.Item Mechanical expectations of a high performance concrete based on a polymer binder and reinforced with non-metallic rebars(2008-10) San-José, José T.; Vegas, Iñigo J.; Moisés Frías, Frías; GENERALA high performance concrete, known as polymer concrete, made up of natural aggregates and an orthophthalic polyester binder, reinforced with non-metallic bars (glass reinforced polymer) has been studied. The material is described at micro and macro level, presenting the key physical and mechanical properties using different experimental techniques. Furthermore, a full description of non-metallic bars is presented to evaluate its structural expectancies, embedded in the polymer concrete matrix. Given the closed porosity obtained in polymer concrete, its microstructure continuity and organic nature of the binder, this material is highly protected against atmospheric conditions, corrosion and chemical attacks. The present research work concludes how the structural compatibility, between polymer concrete and non-metallic bars, is obtained in the monotonic bonding tests by providing higher adherence values than traditional reinforced concrete.Item Multi-criteria decision-making for grading the rehabilitation of heritage sites. Application in the historic center of La Habana(2017-07) Piñero, Ignacio; San-José, José T.; Rodríguez, Patricia; Losáñez, Milagros M.; E&I SEGURAS Y RESILIENTESThe rehabilitation of an historic city centre is approached in this investigation through a multi-criteria decision-making methodology. The methodology assists a panel of experts to take key decisions on rehabilitation options. The viability of the methodology is verified through its practical application in the Historic Centre of La Habana, in which extreme situations are analyzed: a culturally protected (World Heritage) urban zone with many degraded buildings at risk of collapse. In view of the urgency of the rehabilitation decisions, efficient criteria for “emergency actions” on the 3593 buildings of that historic centre were analyzed. The conclusions were that 1033 buildings were in need of one or various emergency actions, with 169 awaiting demolition or restoration and, finally, 597 in need of non-urgent repairs.Item Non-linear analytical model of composites based on basalt textile reinforced mortar under uniaxial tension(2013) Larrinaga, Pello; Chastre, Carlos; San-José, José T.; Garmendia, Leire; Tecnalia Research & InnovationThe recent development of inorganic based composites as low-cost materials in reinforced concrete structural strengthening and precast thin-walled components, requires the creation of models that predict the mechanical behaviour of these materials. Textile Reinforced Mortar (TRM) shows complex stress-strain behaviour in tension derived from the heterogeneity of its constituent materials. This complexity is mainly caused by the formation of several cracks in the inorganic matrix. The multiple cracking leads to a decrease in structural stiffness. Due to the severe conditions of the serviceability limit state in structural elements, the prediction of the stress-strain curve is essential for design and calculation purposes. After checking other models, an empirical nonlinear approach, which is based on the crack control expression included in the Eurocode 2, is proposed in this paper. Following this scope, this paper presents an experimental campaign focused on 31 TRM specimens reinforced with four different reinforcing ratios. The results are analysed and satisfactorily contrasted with the presented non-linear approach.Item Priorización para la rehabilitación de edificaciones en el centro histórico de la habana(2014) Piñero, Ignacio; García, David; Nicolás, Olatz; De La Cruz, Raimundo; San-José, José T.; E&I SEGURAS Y RESILIENTES; TRAZABILIDAD CIRCULAR; LABORATORIO DE TRANSFORMACIÓN URBANAItem A proposal for environmental indicators towards industrial building sustainable assessment(2007-04-01) San-José, José T.; Garrucho, Isaac; Losada, Ramón; Cuadrado, Jesús; Centros PRE-FUSION TECNALIA - (FORMER)The construction sector carries out a very important role in the development of society. It is a basic component of economic activity, having a great influence on employment generation and country growth. The sector generates appreciable environmental changes and effects throughout the planet, leading to gradual exhaustion of natural resources and contamination of basic elements, such as air, water and soil. Recently, there have been advances in favour of more environmentally friendly buildings. Basically, sustainable construction has centred on residential and office buildings. It could be said that there is a lack of sustainability in the construction of industrial buildings, as they present characteristics which differ from other building typologies. This article aims to assess and analyze industrial building environmental effects, and considers a set of green study criteria, such as: location, materials, energy and water consumption, construction and deconstruction characteristics, and waste management in industrial building. At the same time, the studies are hierarchically structured into different assessment elements, such as: criteria, subcriteria and, finally, indicators, comprising the assessment model.