Este artículo presenta la realización de una bóveda gaussiana construida en Jaén, incorporando el uso de la gemelización digital basada en BIM a lo largo de los procesos de diseño y construcción. La bóveda, ejecutada en obra de fábrica e inspirada en el legado de Eladio Dieste, ilustra tanto el potencial estructural como los desafíos de las geometrías gaussianas. Debido a su naturaleza intrínseca, las bóvedas gaussianas permiten la aparición de esfuerzos de tracción limitados, que deben ser cuidadosamente monitorizados y controlados. El proceso de dimensionamiento se inició mediante métodos de diseño paramétrico, lo que permitió la detección temprana de posibles zonas de refuerzo necesario. Durante la construcción, se emplearon técnicas de escáner láser para el seguimiento de los procesos de cimbrado y descimbrado, comparándolos con simulaciones de elementos finitos. El conjunto de acciones se integró en un modelo digital de la bóveda gaussiana que adopta conceptos BIM en abierto, en particular el esquema IFC, estableciendo así un registro digital estandarizado para su posterior reutilización e interoperabilidad.
El Viaducto del Guiniguada, situado en Las Palmas de Gran Canaria, es una obra existente construida en 2003, cuyo tablero de hormigón se ejecutó mediante el procedimiento de avance en voladizos sucesivos. En 2022 se detectó una anomalía, consistente en la rotura de una parte importante de los tendones del pretensado exterior. En inspecciones posteriores se comprobó un problema de mayor alcance, con el deterioro y rotura de numerosos tendones del pretensado de continuidad situados en la tabla inferior del vano central. Ante la imposibilidad de restituir en su totalidad la capacidad estructural mediante un refuerzo interior, se desarrolló una solución singular de pretensado exterior complementario, dispuesto a lo largo de toda la viga cajón que constituye el tablero. Este sistema presenta la particularidad de atravesar la tabla inferior y discurrir por el extremo inferior de un puntal metálico desviador situado en el centro del vano. Su ejecución requirió procedimientos constructivos específicos e innovaciones técnicas singulares, dadas las condiciones geométricas y la altura del viaducto. El sistema permitió recuperar la capacidad estructural perdida y garantizar la durabilidad de la obra, constituyendo una actuación inédita en el ámbito del refuerzo de puentes de hormigón postesado.
La colaboración entre arquitectos e ingenieros, debido a la complementariedad de sus conocimientos, es fundamental en el campo de la arquitectura y la construcción La relación personal entre ambas profesiones juega un papel determinante en la colaboración y el éxito de proyectos y obras. Esta conexión va más allá del papel de cada uno. Implica una comprensión profunda de los requisitos y necesidades del proyecto para que pueda ser desarrollado en un ambiente creativo, propicio para la innovación y resolución de problemas. Mi larga relación con Hugo Corres nos ha permitido llevar a buen término todos los proyectos que hemos compartido. El último en el que estamos trabajando, el Salón de Reinos, dejará grabada nuestra amistad en un edificio de indudable valor histórico.
Construido en 1969, este viaducto de hormigón pretensado venía manifestando algunos problemas hasta que, en febrero de 2020, se detectó la rotura de un tendón. Tras constatarse que cerca del 10% de los tendones presentaba ese problema y que la resistencia característica del hormigón, con un diagnóstico inequívoco de fuerte ataque árido-álcali, apenas llegaba al 50% de la del proyecto −con un nivel de segu-ridad inadmisible e insalvable− se recomendó al Ayuntamiento de Madrid el cierre y el desmontaje de la estructura. El soporte de la ETSICCP-UPM y nuestra perseverancia permitieron completar dos campañas paralelas de reconocimiento post-mortem de gran valor para confirmar el diagnóstico.
One of the key elements for the performance of reinforced concrete stuctures is the interaction of concrete and reinforcement. Introductory examples are mentioned for the successful use of reinforced concrete. Recent developments with 3D concrete printing established two questions concerning the potential use of reinforcements: i) a practical example is presented for 3D concrete printed shell element with tensile chords of FRP reinforcements; ii) interlaminar shear is solved with 3-dimensional reinforcing elements (STAREX). The 3-dimensional reinforcing elements improves the performance of the whole element. FRP reinforcements are used in increasing amount to avoid electrolytic corrosion of the reinforcement. A new reinforcement is: Carbon fibres in cementitious matrix = CFCM, which does not include polymers as matrix but a cementitious matrix is used to improve cooperation both the carbon fibres and concrete. The cementitious matrix reduces sensitivity for high temperatures. With carbon fibres in cementitious matrix reinforcement, the reinforced concrete elements can be produced with no or little cover.
When Fibre Reinforced Polymer (FRP) bars are used as embedded reinforcement in concrete structures, serviceability behaviour often governs the design due to the lower modulus of elasticity of FRPs compared to conventional steel. While many design principles for steel-reinforced concrete remain applicable, the distinct mechanical and bond properties of FRPs require special consideration. In recent years, several international codes and guidelines have been updated or newly issued to address FRP reinforcement. This paper presents a comparative analysis of the main aspects and provisions for serviceability limit state (SLS) design of Glass FRP (GFRP) reinforced concrete flexural members included in Eurocode 2 (2023), fib Model Code 2020 and ACI440.11-22. Stress limitation, crack width and deflections are carefully reviewed, and a design example is included, where the effects of different assumptions and limitations among codes are analysed and discussed.
This article examines the origins, evolution, and consolidation of prestressed concrete in bridge construction in Italy, within the broader international development that began in Europe and North America in the early 20th century. Building on the pioneering insights of Eug & egrave;ne Freyssinet and the theoretical contributions of Gustavo Colonnetti, it traces the path from the first experimental applications to the full establishment of the technology in the postwar years. The study highlights the decisive role of engineers such as Riccardo Morandi and Silvano Zorzi, whose works exemplify both the artisanal and visionary dimension of prestressing and its progressive industrialization. The narrative underscores how technical innovation became intertwined with the lives of its protagonists and with the historical context of Italy's reconstruction, turning each bridge into a symbol of audacity and ingenuity. Finally, it emphasizes the continued relevance of prestressed concrete as a consolidated yet constantly evolving structural technique, still capable of opening new frontiers in contemporary engineering.
This study presents an experimental investigation into the crack initiation and propagation of full-scale load tests performed on encased composite steel-concrete beams, where the concrete is reinforced by conventional rebars together with high-strength steel fibers. Six beams were tested under three-point bending with quasi-static loading, including sagging and hogging configurations. One specimen from each configuration was subjected to various steps of sustained displacement to assess relaxation effects and observe time-dependent cracking phenomena. Full-field strain and crack evolution were monitored using a Digital Image Correlation (DIC) system alongside conventional instrumentation. The DIC system allowed high-resolution tracking of strain patterns, crack initiation and spacing, and crack mouth opening displacement at different load stages. These measurements were taken in a 660 mm wide region corresponding to the midspan. Results show that Steel Fiber-Reinforced Concrete (SFRC) was effective in controlling crack propagation and preventing concrete crushing in compression. At failure, sagging configurations exhibited several distributed cracks in the plastic hinge, and high ductility was achieved due to the favorable presence of the exposed steel flange on the tensile side. In hogging configurations, the steel profile was less effective in the tensile region, resulting in the formation of a dominant crack that concentrated damage at the ultimate state; however, these configurations also exhibited a ductile failure mode. Sustained loading did not significantly reduce the load-bearing capacity, although crack depth and opening did slightly increase. DIC proved effective in revealing strain redistribution and crack branching not captured by traditional sensors. The top SFRC layer of all the beams exhibited compressive strains of up to 1% without complete crushing or spalling, thus maintaining its functionality throughout the test. These findings confirm the validity of the compressive model for SFRC material outlined in Annex L of Eurocode 2, even for full-scale structures.
Computational methods and modeling criteria for life-cycle design, assessment, maintenance, and management of aging structural systems require robust calibration and validation based on data and information gathered from existing structures and experimental tests. This paper provides a contribution along these lines based on criteria, methods, and tools for computational modeling and experimental validation of nonlinear finite element analysis of reinforced concrete (RC) and prestressed concrete (PC) structures. Structural modeling was developed with RC/PC beam finite elements and bi-dimensional finite elements for plane-stress analysis, formulated in accordance with the Modified Compression Field Theory. The formulations were applied to numerical simulation of full-scale load tests on 50-year-old PC bridge deck beams under different loading conditions intended to promote flexural-or shear-dominant failures. The models were informed by the results of laboratory tests on material mechanical properties and residual prestressing stress. The comparison of numerical and experimental results of full-scale load tests allows validation of the nonlinear analysis methods and structural modeling strategies and contributes to the successful implementation in practice of life-cycle-oriented models for deteriorating RC/ PC structures.
The study presents the application of a set of non-destructive testing (NDT) or minor destructive testing (MDT) techniques to masonry components (bricks and mortar joints) for the experimental in-situ measurement of the material's compressive strength. The study focuses primarily on the case of historic masonry construction made of solid brick and lime mortar, with some attention also paid to Portland cement mortar. The techniques investigated include the penetrometer test (PPT), the helical screw pullout test (HPT), the sclerometer (Rebound Hammer, RH), the ultrasonic pulse velocity test (UPV), and the SonReb technique, based on a combination of the latter two tests. Attention is also paid to the double punch test (DPT) on mortar joint samples, despite its more destructive nature. For the PPT and HPT techniques, empirical correlations derived from a large number of tests are proposed to relate the measured parameters (penetration depth and pullout force, respectively) with the compressive strength of bricks and mortar. Furthermore, the SonReb method, based on the integration of results obtained with sclerometers and ultrasounds, has been shown to be applicable, with certain methodological cautions and using a specific correlation, for the estimation of the compressive strength of solid ceramic bricks.
The constant increase in extreme events requires robust buildings capable of withstanding initial local damage without causing propagation of failures that could affect the entire structure or a significant part of it. This article examines the current state of regulations and research on building structural robustness in Spain, more specifically that carried out at the Universitat Polit & egrave;cnica de Val & egrave;ncia, offering a comprehensive overview for both industry professionals and researchers. Although the Spanish Structural Code mentions the need for robust buildings, it lacks clear guidance on implementation, leading to the possible adoption of international standards, such as Eurocode 1 Part 1-7 or the U.S. UFC 4-023-03. These standards consider various strategies for designing robust buildings, highlighting the tying forces method, the alternative load path method, and the design of key elements. The main features of these methods are also described in this article. In terms of research, Spain shows significant progress since important projects introduce innovative strategies to enhance the robustness of existing structures or arrest collapse once initiated. These projects highlight the national potential in developing advanced and effective robustness approaches.
Curved steel plate girders are often utilized in bridges that are built in congested urban areas where complex plan alignments are required. However, the design of curved steel plate girder bridges is more complex than that of equivalent straight ones due to the difficulties associated to the simplification of the design procedures. The current and upcoming versions of Eurocode 3 for plated structures (EN 1993-1-5) do not address steel plate girders curved in plan, especially regarding their behavior against concentrated forces and shear. In that sense, the guidance provided for patch loading and shear design is only applicable to straight girders. Hence, current design guides seem not to cover curved plate girders subjected to patch loading and shear appropriately, or to provide only limited and simplified guidance on how to design them. Therefore, it is necessary to carry out more research in order to achieve a better understanding of the behavior of curved steel plate girders so that suitable design approaches can be developed. This paper presents a comprehensive numerical study on curved steel plate I-girders subjected to patch loading and shear, considering the material and geometric nonlinearities as well as initial imperfections. The numerical models are developed by means of the advanced finite element soft ware ABAQUS and validated against experimental tests available in the literature. From the assessment of the numerical results, practical recommendations are proposed to extend the applicability of the design provisions prescribed in the next version of EN 1993-1-5 for straight steel I-girders to the case of curved steel I-girders.
This article provides an overview of the evolution of bridge prefabrication in Spain, from its beginnings in the 1960s to the present day. It traces the progress made as transportation and lifting equipment enabled the execution of larger and heavier elements, until it became necessary to seek continuous solutions due to transport limitations. This opened the possibility of adapting prefabricated solutions to geometries and structural typologies that, at first glance, would not fall within their usual scope of application. In enabling the use of prefabricated elements in continuous decks, Antonio Mari Bernat played a key role, providing technical support for the new proposed solutions at a time when finite element analysis techniques were beginning to be developed.
Climate change calls into question the durability of infrastructures when environmental actions exceed those foreseen for their design. In the case of reinforcement corrosion, the main corrosion control parameter is the evaporable water content (retained water) of the concrete. Despite its importance that also affects other deterioration processes, data on its content in full-scale structures are scarce, in contrast to the numerous published references on laboratory experiments. This article presents values of the degree of saturation of specimens exposed to the weather and their impact on the corrosion potential, the resistivity of the concrete and the values of the corrosion rate. It can be deduced that the external conditions of temperature and RH are not the controlling factors of the corrosion process, but mainly rainfall. The results show that the only biunivocal relationship with the corrosion rate is that of resistivity, but a "function" has not yet been established that characterizes the environment to deduce its effects on the water content of the concrete and therefore on its resistivity. This lack of correlation of corrosion with the temperature and relative humidity outside calls into question the work published so far on the impact of climate change on infrastructures, since they are based on these external parameters and not on the water retained inside the concrete.
The segmental assembly method is very common in the construction of cable-stayed bridges built using the cantilever method. However, defining the typical segment is a delicate matter that involves making a series of decisions with significant implications for the construction process. Additionally, it is crucial to pay attention to the design of the lifting gantry, specifically how it is supported on the already-built deck and where it picks up the segments to be lifted. These two factors determine the transverse deflecfions of the joints to be connected, the deck front, and the segment being lifted. As a result, the segment assembly can either be as straightforward as any other task or turn into a real headache. This paper explains how these issues were addressed in several cable-stayed bridges built by Dragados in recent years, where the segmental assembly method was used: 1812 Constitution Bridge over C & aacute;diz Bay (Spain), Queensferry Crossing in the UK, the New Champlain Bridge in Canada and the expansion of the Rande Bridge in Vigo (Spain).
This paper presents a Levels-of-Approximation (LoA) unified mechanical model for the shear strength of slender and non-slender reinforced and prestressed concrete beams, with rectangular, T-or I-shaped sections. It applies to members reinforced with steel or fiber-reinforced polymer (FRP) bars, or fiber-reinforced concrete (FRC). Derived from the Multi-Action Shear Model (MASM), the model integrates the key shear transfer actions, including shear carried by the compression chord, residual tensile stresses across the critical crack, dowel action of longitudinal reinforcement and contributions from stirrups, if present. Structured within the LoA framework, the model offers increasing complexity and accuracy for various structural design and assessment scenarios, from preliminary design (LoA 0) to detailed assessment (LoA III). Its adaptability is demonstrated through different extensions, including fatigue for RC beams without stirrups. The model is validated using 2,714 test results from 14 experimental databases, showing consistent predictions with reduced scatter, especially at higher LoAs. This unified mechanical model provides a robust tool for both the design and assessment of structural concrete elements, offering a systematic approach to integrate advanced mechanical understanding with practical engineering needs.
One of the key elements for the performance of reinforced concrete structures is the interaction of concrete and reinforcement. Introductory examples are mentioned for the successful use of reinforced concrete. Recent developments with 3D concrete printing established two questions concerning the potential use of reinforcements: i) a practical example is presented for 3D concrete printed shell element with tensile chords of FRP reinforcements; ii) interlaminar shear is solved with 3-dimensional reinforcing elements (STAREX). The 3-dimensional reinforcing elements improves the performance of the whole element. FRP reinforcements are used in increasing amount to avoid electrolytic corrosion of the reinforcement. A new reinforcement is: Carbon fibres in cementitious matrix = CFCM, which does not include polymers as matrix, but a cementitious matrix is used to improve cooperation both the carbon fibres and concrete. The cementitious matrix reduces sensitivity for high temperatures. With carbon fibres in cementitious matrix reinforcement, the reinforced concrete elements can be produced with no or little cover. This article presents conceptual and technological advances toward the integration of innovative reinforcing materials and technologies in concrete structures.
Built in 1969, this prestressed concrete viaduct had been exhibiting various signs of distress until, in February 2020, crack associated with the rupture of a tendon was detected. This required the implementation of diagnosis to enable an adequate structural assessment of the deck. After confirming that approximately 10% of the tendons exhibited deficiencies related to grouting and early-stage corrosion, and that the characteristic compressive strength of the concrete-with an unequivocal diagnosis of severe alkali-aggregate reaction (AAR)-barely reached 50% of the design value, resulting in an unacceptable and irrecoverable level of structural safety, the Madrid City Council was advised to proceed with the closure and dismantling of the structure. The support from the Engineering School of Madrid (ETSICCP-UPM) and our perseverance made it possible to complete two parallel post-mortem investigation campaigns of great value in confirming the diagnosis. This article presents the lessons learned by the authors during the diagnosis phase, the demolition design stage, and the technical assistance provided throughout execution.
Collaboration between architects and engineers, due to the complementary nature of their expertise, is essential in the field of architecture and construction. The personal relationship between both professions plays a decisive role in collaboration and in the success of projects and works. This connection goes beyond the formal roles of each discipline; it involves a deep understanding of the project's requirements and needs, allowing it to be developed in a creative environment conducive to innovation and problem solving. My long-standing professional relationship with Hugo Corres has enabled us to successfully complete all the projects we have worked on together. The most recent one, the Sal & oacute;n de Reinos, on which we are currently working, will leave our friendship embedded in a building of undeniable historical value.
My students often ask me: "Tell me, prof, what is the use of history of civil engineering?", revisiting the question that opens Marc Bloch's famous book "The Historian's Craft". For some time now, I have been responding to their provocation (I teach civil engineering history) by telling 3 short stories: the stories of three engineers who lived in the nineteenth century, in the twentieth century and in the first century of the new millennium. The first is the story of Charles, born in 1810 in France and a graduate of the & Eacute;cole Polytechnique. Charles tells in first person all the transformations he saw in the world of structural engineering in the nineteenth century: materials, construction techniques, and calculation theory developed so rapidly that we went form the 40-meter span cast-iron Coalbrookdale arch bridge to the 500-meter span Gerber truss Firth of Forth bridge. The story of Giulio, born in 1900 in Rome and graduated in engineering, is similar. He tells us too of the many technical changes linked to reinforced concrete in Italy and around the world, embedded in the political and social history of the twentieth century. In particular, he tells how a great difficulty such as the fascist autarkic propaganda triggered the most interesting experiments of post-war Italy. In particular, he recalls how reinforced concrete, just born in the early 20th century, underwent two genetic mutations in few decades: thin vaults and prestressing, so useful during reconstruction after World War II. Neo Jane, born in Botswana in 2000, tells the last story. She predicts the story of structures in the 21st century. In particular, how everything changed in her university years, after the covid-19 pandemic. And how new rare earths materials applied in bridges, new transportation paradigms, new theories have led to very fast transformations in structures. The three fictional stories should serve to clarify to my students what is the point of studying and researching history in structural engineering.
