Geometry in 18th Century Bell Towers in Bajo Segura, Spain

Bell towers are essential elements of religious architecture, which have been part of villagers’ lives for centuries and have marked their identity and orientation from a far distance. This research provides widens our knowledge of geometrical aspects of bell towers through a search for common building patterns. Throughout the history of construction and architecture, there have been specific studies about particular bell towers, but few have taken a more general approach, studying 18th-century architectural treatises and building warnings for ecclesiastical buildings after the Council of Trent. In the Spanish ecclesiastical territorial organisation, the Diocese of Orihuela and its region (Bajo Segura) had great importance, with outstanding social development and territorial expansion due to the colonising action of the clergy and nobility in the 18th century. In 1829, an earthquake had destructive effects on the area’s architectural heritage. This paper studies the bell towers that endured the earthquake by recording data in situ, generating a catalogue, and analysing and comparing the data obtained. The results outline a construction model that meets the established guidelines of the architectural treatises as far as geometrical proportions and building patterns are concerned

Composition of Corroded Reinforcing Steel Surface in Solutions Simulating the Electrolytic Environments in the Micropores of Concrete in the Propagation Period

In the present work, the composition of a corroded reinforcing steel surface is studied at different pH values (related to different degrees of development in the corroding zones of the corrosion process) in solutions simulating chloride-contaminated environments. The media considered consist of saturated calcium hydroxide solutions, progressively neutralized with FeCl2 or by adding 0.5 M NaCl to the solution. The results found in present work confirm higher levels of acidity in the solutions with higher concentrations of Fe2+.In the present work, emphasis is given to the composition of the oxides in solutions that simulate the conditions that exist inside of a localized corrosion pit as a consequence of the reaction of chloride on reinforcing steel. The oxides were studied using Raman and XPS techniques; the results obtained with both techniques are mutually coherent. Thus, in the passive state, the oxides found are those reported previously by other authors, while in the corroding state, the present results are more comprehensive because the conditions tested studied a variety of pore solution composition with several pH values; we tried to reproduce these values inside the pits in conditions of heavy corrosion (very acidic). The oxides found are those typically produced during iron dissolution and seem not the best route to study the corrosion process of steel in concrete; the electrochemical tests better characterize the corrosion stage

Restauração da fachada da igreja de San Pedro Apostol em Agost, Espanha

This work describes the studies and the intervention carried out for the restoration of the facade of San Pedro Apostol in the parish church of Agost. This facade was made at the end of the 18th century in limestone. After an initial inspection and graphic survey of the facade, the lesions, their origin and the solution to them were identified by using advanced restoration techniques. The stone elements damaged or destroyed by the passage of time are composed of calcite, dolomite and silica, with plaster joints, and have been reconstructed either through the use of new elements or, for the most part, through systems of recovery of the initial volume with the use of a light core of polystyrene, lime mortars, expanded clay, fiberglass and carbon together with infiltrations of resins in the disintegrated areas. After a delicate intervention process using innovative techniques, the facade was completed in June 2023.Este trabajo describe los estudios realizados y la intervención llevada a cabo para la restauración de la portada de la fachada de San Pedro Apóstol en la Iglesia parroquial de Agost. Esta portada se realizó a finales del siglo XVIII en piedra calcárea. Tras una primera inspección y levantamiento gráfico de la misma se identificaron las lesiones, su origen y la solución a las mismas, empleando técnicas avanzadas de restauración. Los elementos de piedra dañados o destruidos por el paso del tiempo están compuestos por calcita, dolomita y sílice, con juntas de yeso, y se han reconstruido bien mediante el uso de nuevos elementos o, en su mayor parte, mediante sistemas de recuperación del volumen inicial con la utilización de un núcleo ligero de poliestireno, morteros de cal, arcilla expandida, fibra de vidrio y carbono junto con infiltraciones de resinas en las zonas disgregadas. Tras un proceso delicado proceso de intervención con técnicas innovadoras la fachada ha finalizado su restauración en junio de 2023.Este trabalho descreve os estudos efetuados e a intervenção realizada para o restauro da fachada de São Pedro Apóstolo na igreja paroquial de Agost. Esta fachada foi realizada no final do século XVIII em pedra calcária. Após uma primeira inspeção e levantamento gráfico da fachada, foram identificadas as lesões, a sua origem e a solução para as mesmas, utilizando técnicas avançadas de restauro. Os elementos pétreos danificados ou destruídos pela passagem do tempo são compostos por calcite, dolomite e sílica, com juntas de gesso, e foram reconstruídos quer através da utilização de novos elementos, quer, na sua maioria, através de sistemas de recuperação do volume inicial com recurso a um núcleo leve de poliestireno, argamassas de cal, argila expandida, fibra de vidro e carbono, juntamente com infiltrações de resinas nas zonas desagregadas. Após um delicado processo de intervenção com recurso a técnicas inovadoras, a fachada foi concluída em junho de 2023

The usage of TLS and photogrammetry during the restoration process of Spanish national monument

This article presents the multidisciplinary methodology employed in the restoration of a sixteenth century renaissance building with gothic vaults. The use of precise instrumental techniques like TLS (Terrestrial Laser Scanning) or photogrammetry are proposed to obtain the geometry of the building before, during and after the intervention. Obtaining the point clouds of the Refectory of the Santo Domingo de Orihuela School in their different restoration stages allows monitoring the vaults, studying their structural behaviour and deformations with the comparison of their original state, unloaded state and the new loading after the execution works. A work methodology that is proposed in this article could be applied to any restoration work of patrimonial architecture. The original deformations have been verified and quantified and the final state of the intervention has been documented with respect to the original state

Ivabradine in acute heart failure: Effects on heart rate and hemodynamic parameters in a randomized and controlled swine trial.

Background: Acute heart failure patients could benefit from heart rate reduction, as myocardial consumption and oxidative stress are related to tachycardia. Ivabradine could have a clinical role attenuating catecholamine-induced tachycardia. The aim of this study was to evaluate hemodynamic effects of ivabradine in a swine model of acute heart failure. Methods: Myocardial infarction was induced by 45 min left anterior descending artery balloon occlusion in 18 anesthetized pigs. An infusion of dobutamine and noradrenaline was maintained aiming to preserve adequate hemodynamic support, accompanied by fluid administration to obtain a pulmonary wedged pressure ≥ 18 mmHg. After reperfusion, rhythm and hemodynamic stabilization, the animals were randomized to 0.3 mg/kg ivabradine intravenously (n = 9) or placebo (n = 9). Hemodynamic parameters were observed over a 60 min period. Results: Ivabradine was associated with a significant reduction in heart rate (88.4 ± 12.0 bpm vs. 122.7 ± 17.3 bpm after 15 min of ivabradine/placebo infusion, p < 0.01) and an increase in stroke volume (68.8 ± 13.7 mL vs. 52.4 ± 11.5 mL after 15 min, p = 0.01). There were no significant differences in systemic or pulmonary arterial pressure, or significant changes in pulmonary capillary pressure. However, after 15 min, cardiac output was significantly reduced with ivabradine (–5.2% vs. +15.0% variation in ivabradine/placebo group, p = 0.03), and central venous pressure increased (+4.2% vs. – 19.7% variation, p < 0.01). Conclusions: Ivabradine reduces heart rate and increases stroke volume without modifying systemic or left filling pressures in a swine model of acute heart failure. However, an excessive heart rate reduction could lead to a decrease in cardiac output and an increase in right filling pressures. Future studies with specific heart rate targets are needed.pre-print2533 K

Inhibidores en el inicio y propagación del proceso de corrosión de las armaduras en el hormigón armado

Se han ensayado muchas sustancias como inhibidores de corrosión en el hormigón armado. De entre ellas, la que tiene mayor aceptación por su eficacia y compatibilidad con el hormigón, es el nitrito sódico. Se ha considerado el caso particular del hormigón armado conteniendo iones cloruro: los cloruros provocan una corrosión localizada al romper puntualmente la capa de óxidos pasivantes. Los nitritos ejercen una acción competitiva contra estas roturas locales y reparan la capa pasivante manteniendo la integridad del acero. Para ello, la proporción de nitritos debe ser calculada en cada caso en función de la cantidad de cloruros presentes. Se han estudiado varios compuestos: Nitrito sódico, Nitrato sódico, Hexametiltetraamina y Reductor de Cr VI, referentes a la inhibición que provocan en el proceso de corrosión de las armaduras en el hormigón armado, cuando este proceso ya ha comenzado, o sea, en su inicio y período de propagación. Este trabajo de investigación ofrece los resultados y conclusiones obtenidas del comportamiento de los inhibidores estudiados

Inhibidores en el inicio y propagación del proceso de corrosión de las armaduras en el hormigón armado

Se han ensayado muchas sustancias como inhibidores de corrosión en el hormigón armado. De entre ellas, la que tiene mayor aceptación por su eficacia y compatibilidad con el hormigón, es el nitrito sódico. Se ha considerado el caso particular del hormigón armado conteniendo iones cloruro: los cloruros provocan una corrosión localizada al romper puntualmente la capa de óxidos pasivantes. Los nitritos ejercen una acción competitiva contra estas roturas locales y reparan la capa pasivante manteniendo la integridad del acero. Para ello, la proporción de nitritos debe ser calculada en cada caso en función de la cantidad de cloruros presentes. Se han estudiado varios compuestos: Nitrito sódico, Nitrato sódico, Hexametiltetraamina y Reductor de Cr VI, referentes a la inhibición que provocan en el proceso de corrosión de las armaduras en el hormigón armado, cuando este proceso ya ha comenzado, o sea, en su inicio y período de propagación. Este trabajo de investigación ofrece los resultados y conclusiones obtenidas del comportamiento de los inhibidores estudiados

The Useful Life of Reinforced Concrete Structures with Reinforcement Corrosion Due to Carbonation in Non-Aggressive and Normal Exposures in the Spanish Mediterranean

Some reinforced concrete structures must be repaired at an early stage in their life due to the oxidation processes suffered by their reinforcements; such processes involve serious pathologies that affect the stability and safety of buildings. Spanish legislation distinguishes several classes of environments, with non-aggressive and normal exposure providing a longer useful life of the structure. The present study shows that some structural elements in reinforced concrete, mainly the pillars in the area of contact with the ground, are exposed to significant corrosion by carbonation. This position of the structural elements dramatically and abruptly shortens the useful life of the models provided for the current regulations. A total of 17 pillars in 10 buildings of different ages and locations in the Spanish Mediterranean area, not subject to the presence of chlorides, have been analyzed. These buildings are situated in environments considered by the standard as normal and non-aggressive. The actual carbonation that these elements present have been compared with that which can be derived from the model established by Spanish regulations. Of these pillars, 14 present a carbonation higher than that derived from the model, and the last three pillars largely conform to the figures of the model. This significant deviation shows the need for a revision of the Spanish EHE 08 regulation, which should include aspects such as the action of dampness by capillarity and the differences in electrochemical potential between the different materials

Simple and Resistant Construction Built with Concrete Voussoirs for Developing Countries

This paper provides a solution to the covering of spaces in buildings by substituting masonry vaults comprising voussoirs for traditional horizontal slabs. They are made of precast concrete with cement mortar joints. They are intended for covers with maintenance loads but without live loads and their function is to create a singular vaulted interior space. The vaults must be supported by a vertical auxiliary traditional structure, such as a plane frame of beams and pillars made of reinforced concrete, or by masonry walls. The horizontal reaction forces have to be borne by steel braces or buttresses. The basic geometry is standardized by a span of 6 m, with a rise in the key of 0.80 m and a constant vault thickness of 0.28 m. The curvature of the arch is achieved by the modification of the thickness of the mortar joints; spans of 3–6 m, with different rises of the arch, can be easily obtained. The main aim of this research is the reintroduction of arches and vaults as structural elements in present day architecture, which have the added advantage of not needing the addition of steel; this eliminates the risk of steel corrosion. The use of these techniques can also provide an easy way to construct homes in developing countries that lack adequate resources and tools. The solution aims toward more sustainable construction and is specifically designed for new buildings; however, it can also be used in building rehabilitation cases