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Bridge strikes—events where over-height vehicles impact bridge superstructures—are common across the United States and pose significant challenges for bridge owners. When a bridge strike occurs, bridge owners must assess the damage and determine what, if any, action is required. A survey of state highway agencies was conducted, and 23 responses were received. States reported general metrics about low-clearance bridges and bridge strikes, and data from the National Bridge Inventory were analyzed to provide additional insight. States also reported information about inspection, analysis, and repair practices for damaged girders. Overall, reported practices vary greatly between states and rely significantly on engineering judgement; there is potential to improve efficiency and efficacy. Results can be used to inform future research directions regarding steel girders damaged in bridge strikes, such as innovative methods for damage inspection, assessment, and repair.

This report presents the behavior of reinforced concrete beams retrofitted with carbon fiber reinforced polymer (CFRP) sheets and ultra-high performance concrete (UHPC) jackets in a multi-hazard environment. Following the procedural protocol of a published standard, the beams are cyclically loaded under thermomechanical distress at elevated temperatures, varying from 25oC (77oF) to 175oC (347oF), in order to examine their hysteretic responses alongside ancillary testing. The thermal conductivity of UHPC is higher than that of ordinary concrete by more than 62% and, according to a theoretical inference, premature delamination would not occur within the foregoing temperature range. The difference of load-carrying capacities between the strengthened and un-strengthened beams declines with temperature. While the UHPC+CFRP retrofit scheme is beneficial, CFRP plays a major role in upgrading the flexural resistance. The thermomechanical loading deteriorates the hysteretic loops of the beams, thereby lowering the stiffness and capacity. Elevated temperatures are concerned with the pinching, plasticity, characteristic rigidity, stress redistributions, and energy-release patterns of the beams. Due to the retrofit, the configuration of plastic hinges alters, and the localized sectional deformations form a narrow damage zone. The adverse effects of the temperatures on rotational stiffness are pronounced during the early loading stage of the beams.

This report summarizes the research on enhancing the current inspection protocols for MassDOT using 3D scanning technologies. The first part of the report presents a thorough review of the current methods using 3D scanning techniques for bridge inspection. The report also includes laboratory and field scans on corroded beam ends. The research team used different scanning techniques, scanning technologies, and post-processing techniques to find the method that would yield the most accurate result and be the most implementable by the DOT. Part of the presented research was to develop and validate a semiautomated point cloud data/scanning extraction method. Finally, the research team developed a method for 3D scanning to be used in bridge inspection. The main goal of the project is presented at the end of the report and consists of a comprehensive and implementable protocol for 3D-scanning-enriched bridge inspection.

Ultra-high-performance concrete (UHPC) has been used increasingly in the past decade due to its high strength, rapid strength gain, and enhanced durability. UHPC is a cement-based material that typically has a low w/cm ratio, high paste content, and a 2% volume fraction of 0.5-in. long, straight, high-strength steel fibers. Most commercially available UHPC mixtures are also proprietary, or company-owned, which tends to elevate its cost. To lower the cost of UHPC in Kansas, this research aimed to develop non-proprietary UHPC using primarily Kansas-based materials. It was important that the proposed mixture gain strength quickly for use in accelerated bridge construction; the proposed mixture proportions have produced measured 1-, 7-, and 28-day compressive strengths as high as 13.1, 16.8, and 19.6 ksi. Also, because UHPC typically exhibits high early-age shrinkage relative to conventional concrete, this research explores shrinkage-limiting methods, including a shrinkage reducing admixture (SRA), a shrinkage compensating admixture (SCA), and prewetted lightweight aggregates (LWAs). The SRA effectively reduced UHPC shrinkage by one-third 30 to 60 days after mixing, but not at 90 days. The SCA reduced shrinkage throughout the 90 days of monitoring, and the effect was highly dose dependent. LWA did not reduce UHPC shrinkage in this study, but further research is needed since this finding conflicts with prior research. Results are also reported from tension and bending tests of UHPC with different volume fractions of high-strength straight and hooked steel fibers. Every specimen tested exhibited strain hardening in tension or deflection hardening in bending, suggesting that both fiber types are similarly effective. However, further research is needed to conclusively compare fibers due to the scope of the reported tests.

This study presents a numerical modeling approach that effectively models the response of prestressed girder bridges under lateral impact loads using LS-DYNA, a finite element analysis (FEA) program. The proposed methodology was validated using experimental data from reinforced concrete beam impact tests, prestressed beam impact tests, and static testing of a full-scale bridge. Thirteen models were intensively validated using existing experimental data. These validated models were then utilized to conduct a comprehensive parametric study, examining various influential factors on the dynamic response of bridge prestressed concrete girders (BPCG) when subjected to vehicle collisions. Factors investigated included vehicle speed and mass, girder span, and girder type. Semi-trailer speed up to 144 km/h and girder spans range from 15.24 to 27.43 m were investigated. It was found that the shear failure mode was directly influenced by the girder stiffness. Also, the transformation from global shear to localized shear failure occurred when the girder span increased by a factor of 1.8. A proposed value of 1520 kN was proposed for the peak impact force resulting from the tractor semi-trailer. The findings indicate that the proposed modeling technique can be effectively used to investigate the structural response of prestressed girder bridges subjected to lateral impact loads.

In recent decades, there has been an increase in catastrophic vehicle-bridge collisions worldwide due to rapid infrastructure development and increased traffic. This study, which addresses the critical research gap in understanding lateral impact loads on prestressed flanged concrete bridge girders, has the potential to impact the field significantly. The paper experimentally investigates the effect of concrete decks as a restraining condition on two small-scale (20 ft long) prestressed girders: Isolated and T-shaped. Using a controlled impact load setup, these girders were subjected to lateral impacts with varying bending and torsional constraints. The test facility simulated over-height vehicle collisions using a 660 lbs. impact cart on an elevated steel track, allowing it to roll down the track with a changing height of 7.8 ft. Results show that T-beam girders exhibit higher peak impact force than isolated beams, indicating better impact resistance. Moreover, the lateral displacement in the T-beam at the impact location decreased significantly by 82% compared to the isolated beam. However, failure patterns differ; prestressed beams typically experience shear failure, while conventional beams tend to fail in flexure. This research, therefore, contributes to improving the safety and resilience of bridge structures in real-world applications, design, and maintenance practices.

Ultra-high-performance concrete (UHPC) has been used increasingly in the past decade due to its high strength, rapid strength gain, and enhanced durability. UHPC is a cement-based material that typically has a low w/cm ratio, high paste content, and a 2% volume fraction of 0.5-in. long, straight, high-strength steel fibers. Most commercially available UHPC mixtures are also proprietary, or company-owned, which tends to elevate its cost. To lower the cost of UHPC in Kansas, this research aimed to develop non-proprietary UHPC using primarily Kansas-based materials. It was important that the proposed mixture gain strength quickly for use in accelerated bridge construction; the proposed mixture proportions have produced measured 1-, 7-, and 28-day compressive strengths as high as 13.1, 16.8, and 19.6 ksi. Also, because UHPC typically exhibits high early-age shrinkage relative to conventional concrete, this research explores shrinkage-limiting methods, including a shrinkage reducing admixture (SRA), a shrinkage compensating admixture (SCA), and prewetted lightweight aggregates (LWAs). The SRA effectively reduced UHPC shrinkage by one-third 30 to 60 days after mixing, but not at 90 days. The SCA reduced shrinkage throughout the 90 days of monitoring, and the effect was highly dose dependent. LWA did not reduce UHPC shrinkage in this study, but further research is needed since this finding conflicts with prior research. Results are also reported from tension and bending tests of UHPC with different volume fractions of high-strength straight and hooked steel fibers. Every specimen tested exhibited strain hardening in tension or deflection hardening in bending, suggesting that both fiber types are similarly effective. However, further research is needed to conclusively compare fibers due to the scope of the reported tests.

This paper presents numerical pushover analyses on multiple bay pallet racks, aiming to quantify variations in global ductility when using different beam-to-upright connections. The connections differ in the layout of the beam-to-endplate welding, being one of them a technological novelty. They are modeled with envelopes of monotonic and cyclic moment-rotation curves obtained from component tests and presented in previous research. Moreover, the influence of the level height is studied throughout two different rack configurations. A single-column model for multiple bay racks, made with 3D beams and shells, is presented and compared with simpler 2D models to quantify the influence of 3D effects and upright perforations. Results exhibit that the novel connection improves the capacity to absorb energy, but an inappropriate rack configuration can lead to a soft-story mechanism, thus not taking full advantage of its ductility., Peer Reviewed, Postprint (published version)

Rack uprights are commonly mono-symmetric open thin-walled members with regular perforations along their length. These perforations are used to enable the connection with Rack upright frames of conventional pallet racking systems are obtained by the assembly of uprights and braces or diagonals. Rack uprights are commonly mono-symmetric open thin-walled members with regular perforations along their length. These perforations are used to enable the connection with braces and beams by means of bolts or hooks. The structural behaviour of a rack upright frame under a pure compression load, in which the buckling phenomenon has a relevant influence, depends on several geometrical parameters, such as the column cross-sectional dimensions, perforations characteristics, frame length, distance between braces, etc. Therefore, these particular issues should be considered to perform a proper structural analysis. In this paper, the structural behaviour of a pallet rack frame under a pure compression load is analysed by means of eigenbuckling and geometrically nonlinear Generalized Beam Theory (GBT) analyses. The influence of GBT deformation modes involved in the analysis is discussed. Moreover, different approaches to reproduce the connection between uprights and braces are presented and discussed. Finally, GBT results are compared with beam, shell finite element analysis and experimental values., Postprint (published version)

This paper presents a cross-sectional optimization procedure to increase the load carrying capacity of a perforated rack column under a compression load. The optimization method is based on a Genetic Algorithm (GA) combined with the Generalized Beam Theory (GBT), which allows to take perforations as well as sectional deformations into account. The results indicate that the optimal cross-section geometry depends on the dominant buckling mode. Therefore, a combined optimization criterion to consider distortional and global buckling is defined. Finally, nonlinear shell finite elements analyses are done in order to assess the structural behaviour of optimized cross-sections., The author J. Bonada is a Serra Húnter Fellow, Postprint (published version)

This thesis studies the vibration pattern synthesis in structures using the Dynamic Mode Decomposition (DMD) method. This numerical model is used for one degree of freedom, to know the axial response, according to x. Firstly the effectiveness of the DMD method is evaluated and give good results to reconstruct the signal, applying to initial conditions of the structure's vibration to extract the shape and temporal characteristics of the DMD modes, which were then used to synthesize the desired vibration pattern in the structure. Next, QR factorization is used in order to find sensor placement. Results showed that the DMD method, combined with QR factorization, can effectively synthesize the desired vibration pattern in structures. However, conditions about spacing of the sensors is necessary to optimize the interpolation. Regarding further research, it’s needed to study the method's limitations and potential application in more complex systems or when dealing with high-frequency data., Incoming

Las estructuras son una gran parte de los proyectos arquitectónicos y nuestras decisiones en todas las fases de diseño las condicionan en gran medida. Es por esto que como arquitectos debemos conocer y saber las dimensiones aproximadas de las estructuras que proyectamos. Este trabajo se centra en la presentación de la viga atirantada o viga Fink, un sistema constructivo que ofrece ligereza, tanto material como espacial, en edificios de grandes luces como pabellones o auditorios. Este sistema busca proponer proyectos cuya estructura es más ligera y por tanto más económica y ecológica gracias a un diseño en que la estructura deja de ser un simple elemento pasivo y pasa a estar activada. Este tipo de soluciones en que la estructura pasa a estar diseñada para trabajar junto al edificio requieren de coordinación con el diseño del resto de partes del edificio, por lo que es importante que, aunque no realicemos un cálculo preciso en cada uno de los pasos del proyecto, sepamos qué dimensiones de predimensionado irán tomando en cada paso del proceso., Structures are a large part of architectural projects and our decisions in all design phases condition them to a great extent. That’s why as architects we must know the approximate dimensions of the structures we are going to build. This thesis focuses on the presentation of the strut and tie beam or Fink truss, a construction system that offers lightness, both material and spatial, in buildings with large spans such as pavilions or auditoriums. This system seeks to propose projects whose structure is lighter and therefore more economical and ecological thanks to a design in which the structure ceases to be a simple passive element and becomes activated. This type of solution in which the structure is designed to work together with the building requires coordination with the design of the rest of the building's parts. It’s important that although we do not carry out a precise calculation in each of the steps of the project, we know what approximate dimensions they will take in each step of the process., Award-winning

En este estudio se ha llevado a cabo la simulación de un ensayo realizado en los laboratorios de la Universidad Politécnica de Cataluña. El ensayo en cuestión consistió principalmente, en aplicar una carga cíclica a vigas reforzadas con FRCM (FabricReinforced Cementitious Matrix) de fibras vegetales (algodón y cáñamo) y estudiar su comportamiento. El entorno utilizado para realizar las simulaciones es ANSYS 2020 R2, concretamente uno de sus módulos; ANSYS Mechanical. Antes de realizar las simulaciones, se ha investigado el estado actual de la tecnología en la que se trabaja. Han sido analizados trabajos con vigas reforzadas con FRCM, cargas estáticas, o refuerzos vegetales como temas principales. Después de conocer las últimas novedades sobre el tema del proyecto, se empezaron a diseñar las primeras simulaciones. Se empezó calibrando la viga de control, y más adelante se añadieron los refuerzos y se ajustaron sus parámetros. En este trabajo, se redacta todos los comandos utilizados en el software, siendo útil como guía para otras simulaciones similares. Tras conseguir ajustar todas las variables que afectaban el comportamiento de la viga, se han conseguido muy buenos resultados, la simulación con el error mínimo es del 2 %, y la simulación menos ajustada tiene un error del 12 %. Además, se han comparados con los resultados reales obtenidos de los ensayos, cumpliendo así con los objetivos principales. Finalmente, se ha utilizado el mismo modelo para simular otras vigas con el mismo tipo de refuerzo, pero con diferente tipo de malla. Así concluyendo que este modelo es capaz de prever el comportamiento de las vigas conociendo las características de su malla. Esta validación se realizó comparando los nuevos resultados con ensayos experimentales., In this study, the simulation of a test carried out in the laboratories of the “Universidad Politécnica de Cataluña” has been carried out. The test in question consisted mainly of applying a cyclic load to beams reinforced with FRCM (Fabric-Reinforced Cementitious Matrix) of vegetable fibres (cotton and hemp) and studying their behaviour. The environment used to carry out the simulations is ANSYS 2020 R2, specifically one of its modules; ANSYS Mechanical. Before starting out the simulations, the current state of the art of the technology used has been investigated. Works with FRCM reinforced beams, static loads and plant reinforcements as main topic were analysed. After learning about the latest developments on the subject, the first simulations were designed. We started by calibrating the control beam model, and later we added the reinforcements and adjusted their parameters. In this work, all the commands used in the software are written, being useful as a guide for other similar simulations. After adjusting all the variables affecting the behaviour of the beam, very good results have been achieved, the simulation with the minimum error is 2 %, and the least adjusted simulation has an error of 12 %. Moreover, they have been compared with the real results obtained from the tests, thus fulfilling the main objectives. Finally, the same model has been used to simulate other beams with the same type of reinforcement, but with a different type of mesh. Thus, concluding that this model is able to predict the behaviour of the beams knowing the characteristics of their mesh. This validation was carried out by comparing the new results with experimental tests.

This paper presents numerical simulations of a suite of cantilever seismic tests of speed-lock connections between beam and upright members of adjustable pallet rack systems. The tested specimens differ in the endplate-to-beam weld beads geometric configuration; the experimental results show that each weld configuration leads to different behavior, significantly affecting the connection capacity and ductility. As a result, the performed numerical simulations aim to better understand and deepen these observations. Special attention is paid to the initial (elastic) behavior of the tested assembly, albeit the stress redistribution after the first yielding has also been studied and found to be relevant. The numerical results are satisfactory compared with the experimental ones, and specific remarks are derived. This work is a part of a broader research effort aimed to improve the dissipative seismic behavior of racks; such research activity involves also upright-base plate connections testing, advanced numerical simulation, and proposal of rack ductility behavior factors., Peer Reviewed, Postprint (published version)

Aquest treball és un estudi de calibració d’un model simulat de biga reforçada amb malles vegetals a través de l’anàlisi modal. En el treball es crea un model de biga simulada que reflecteixi de la manera més similar possible el comportament de les bigues reals. L’objectiu de la simulació de les bigues és poder crear un model que pugui reflectir correctament els comportaments de les bigues experimentals. Gràcies a aquest model es pot reduir els costos tant econòmics com ambientals de l’experimentació amb bigues i el temps necessari que s’hauria d’invertir en la seva fabricació. L’estudi és purament simulat, ja que es la part que més ocupa i la més important del treball. Per dur a terme les simulacions es necessitaran dos programes, SolidWorks, que s’utilitzarà per generar i assemblar les diferents parts de la geometria de la biga i l’ANSYS Workbench, que s’utilitzarà per simular les bigues. Els materials principals que s’estudiaran són el formigó, morter, acer, cànem i cotó. Els paràmetres a trobar per dur a terme l’anàlisi són les freqüències naturals de les bigues, les seves formes modals corresponents i la diferència entre els resultats experimentals i els simulats que s’obtindran calibrant les propietats de densitat i mòdul de Young dels diferents materials. A partir dels resultats obtinguts es realitzaran les comparacions corresponents entre els assajos experimentals i les simulacions, si la diferència es inferior a 10% s’accepten els resultats com a bons. Es pot dir que el principal objectiu del treball s’ha pogut assolir gràcies a la diferència entre els resultats experimentals i els simulats. A través d’aquest paràmetre es pot calibrar correctament el model per aproximar-se el màxim possible a les proves experimentals., This work is a calibration study of a simulated model of a reinforced beam with plant mesh through modal analysis. This work creates a simulated beam model able reflect in the most similar way possible the behaviour of real beams. The goal of the beam simulation is to create a model that can accurately reflect the behaviour of experimental beams. Thanks to this work it’s possible to reduce both economic and environmental costs of experimenting with beams and the time needed to manufacture said beams. The study is purely simulated, as it is the biggest and most important part of the work. Two programs will be needed to perform the simulations, SolidWorks, which will be used to generate and assemble the different parts of the beam geometry, and ANSYS Workbench, which will be used to simulate the beams. The main materials to be studied are concrete, mortar steel, hemp, and cotton. The parameters needed to complete the study are the natural frequencies of the beams, their corresponding modal forms, and the difference between the experimental and simulated results that will be obtained by calibrating physical properties of the density and the Young modulus of the different materials. Based on the results obtained, the corresponding comparisons will be made between the experimental tests and the simulations, if the difference is less than 10%, the results will be accepted as satisfactory. It can be said that the main goal of the study was achieved thanks to the difference between experimental and simulated results. Through this parameter, the model can be correctly calibrated to resemble as closely as possible the experimental tests.

In the past, achieving high strength was considered by the Texas Department of Transportation (TxDOT) as the main design criteria for formulating high-performance concrete (HPC). TxDOT considers mix design options 1–5 in Item 421 as HPC, and these options were developed for alkali silica reaction (ASR) mitigation and not for other durability aspects. Very little work has been done to determine if these options are adequate to provide long-term durability often needed when HPC is specified. The main objective of this project was to develop performance specifications for HPC bridge deck concrete to ensure high performance in terms of durability. The Texas A&M Transportation Institute (TTI) conducted a combination of field investigation and laboratory evaluation to achieve this objective. TTI used both conventional and innovative new lab testing methods to determine the key durability performance characteristics (i.e., addressing chloride and freeze-thaw durability issues based on formation factor-based transport properties, cracking potential based on both autogenous and drying shrinkage considerations, ASR evaluation using rapid and reliable test methods, etc.) for developing performance specifications. TTI then developed specific prescriptive requirements to formulate a wide variety of prescriptive mixtures that can meet the durability requirements matching different exposure conditions. TTI has developed a practice-ready performance evaluation tool that addresses three critical durability parameters of HPC mixtures: ASR, shrinkage-based cracking potential, and chloride-induced rebar corrosion. The use of the tool serves as a combined approach for both performance- and prescriptive-based concrete specifications for HPC bridge deck concrete. This method could potentially encourage contractors to effectively use these finetuned prescriptive HPC mixtures without the need to conduct additional long-duration testing and ensure making long-lasting durable concrete and sav

A butterfly web girder is a box girder that has discretely distributed side-surface openings. Due to these openings, butterfly web girders show better aerodynamic performance than conventional box girders. This study aims to investigate the effects of side-surface openings on the aerodynamic instability of a box girder when it is placed in tandem with another girder. In addition, this study aims to investigate whether the aerodynamic instability of one girder is affected by the side-surface openings of an adjacent girder. A series of wind tunnel tests will be carried out on a butterfly web girder and conventional box girder, with another rigidly supported butterfly web girder or conventional box girder, respectively, at its upstream or downstream side. The fixed downstream girder increased the galloping instability of the upstream girder, and the fixed upstream girder amplified the vortex-induced vibration of the downstream girder. The side-surface openings of the upstream girder stabilized its galloping and vortex-induced vibration, irrespective of the type of girder downstream. The side-surface openings of the downstream girder stabilized its vortex-induced vibration independent of the type of girder upstream.

La present tesi, s'ha centrat en el desenvolupament d'un model de resistència a tallant de bigues pretensades amb armadures preteses de FRP, vàlid per a seccions rectangulars, T o I, amb o sense armadures transversals de FRP. Es tracta de l'adaptació d'un model desenvolupat a la UPC (Barcelona) i a la UIB (Mallorca) per esforç tallant en bigues, anomenat "Multi-action Shear Model (MASM)", que posteriorment va ser estès a bigues de formigó pretensat amb armadures d'acer i a bigues armades amb FRP. En aquesta tesi s'ha reformulat i verificat experimentalment el model per a bigues pretensades amb armadures d'acer, i s'ha adaptat al cas de pretesat amb armadures actives de FRP, tenint en compte els efectes de les seves propietats a la resistència a tallant. S'ha observat que l'adherència entre l’armadura de FRP i el formigó juga un paper determinant en la resistència a tallant. Això ha propiciat la realització d’una formulació per a identificar la ruptura deguda a una longitud d'ancoratge insuficient. Aquesta formulació s'ha verificat amb una sèrie d'assajos experimentals mencionats a la bibliografia, havent obtingut bona concordança en la tipologia de trencament i una bona precisió en les prediccions de la resistència, tot i les incerteses existents en aquest camp. D’altra banda, el model s’ha utilitzat per dur a terme una predicció dels assajos a tallant que es realitzaran en l'àmbit del projecte Straduravius., La presente tesis se ha centrado en el desarrollo de un modelo de resistencia a cortante de vigas pretensadas con armaduras pretesas con armaduras activas de FRP. Se trata de la adaptación de un modelo desarrollado en la UPC (Barcelona) y en la UIB (Mallorca) para cortante en vigas, llamado “Multi-action Shear Model (MASM)”, que posteriormente fue extendido a vigas de hormigón pretensado con armaduras de acero y a vigas armadas con FRP. En esta tesis se ha reformulado y verificado experimentalmente el modelo para piezas pretensadas con armaduras de acero y se ha adaptado a vigas pretensadas con barras de FRP como armadura activa, incluyendo los efectos de sus propiedades en la resistencia a cortante. Se ha observado que la adherencia entre el FRP y el hormigón juega un papel fundamental en la resistencia a cortante, lo cual ha dado lugar al desarrollo de una forma de identificar la rotura por insuficiente anclaje. Ello ha sido verificado con una serie de ensayos disponibles en la bibliografía, en los que se ha obtenido una buena concordancia en la forma de rotura y una buena precisión en las predicciones de la resistencia, a pesar de las incertidumbres en este campo. Por otra parte, el modelo ha sido utilizado para hacer una predicción de los ensayos que se realizarán en el ámbito del proyecto Straduravius, el Laboratorio de tecnología de estructuras y materiales de la UPC., The present Master’s thesis has focused on the development of a mathematical model of shear strength on prestressed pre-tensioned concrete beams, with FRP prestressing reinforcements, valid for rectangular, T and I sections, with or without transversal FRP reinforcements. This model is based on a previous one developed in the UPC and at the University of Balearic Islands (UIB), for the shear strength of steel reinforced concrete beams, named “Multi-action Shear Model (MASM)”, which was later extended to prestressed concrete beams with steel reinforcements and to RC beams using FRP as passive reinforcement. In this thesis, first the model has been reformulated and experimentally verified for prestressed concrete beams with steel reinforcement and, subsequently, has been adapted to beams with FRP active reinforcement, accounting for the effects of FRP’s properties on their shear strength. Moreover, it has been observed, that bond between FRP and concrete plays a relevant role in determining the shear strength. Therefore, a mathematical model to identify when such type of failure takes place, has been developed in this thesis. The model has been verified using the shear tests available in the literature, obtaining a good concordance on the failure mode and good precision on the strength predictions, even within the uncertainties of the field. In addition, the model has been used to predict the results of the shear tests to be performed within the scope of Straduravius project.

This paper is the result of both experimental and numeric analyses on pallet rack components. Two cyclic testing protocols for beam-end connectors of adjustable racking systems are compared; such experiments are named as “code type” and “Castiglioni”. Both protocols share the same test mock-up: an assembly of a doubly-pinned upright segment with a cantilever beam specimen. These tests consist in an up-to-failure increasing push-pull process at the free beam end. In the “code type” test, the imposed displacement loops are centered around zero; conversely, in the “Castiglioni” tests, both upward and downward displacement segment runs are centered around a vertical static equilibrium situation (to take the gravitational load into account). The “code type” test is expected to result in a higher number of cycles than the “Castiglioni” one because of the two following features of the latter: (i) the gravitational load is always present, thus resulting in a higher demanding test, and (ii) the failure point is precisely predefined and usually produced before the total breakdown. This paper describes and compares experiments using both protocols. Additionally, these tests are numerically simulated., Peer Reviewed, Postprint (published version)

A través de los años se ha estudiado que el comportamiento del hormigón armado sometido a esfuerzos transversales se ve muy influido por el estado multi-axial de tensiones en el hormigón y el comportamiento anisótropo a que da lugar, después de la fisuración, debido a la distinta resistencia a tracción y compresión. Este mismo comportamiento depende de la capacidad de las fisuras de una viga de hormigón para transmitir tensiones, según su abertura e interacción con la región de la viga que permanece sin fisurar. Por lo tanto, podemos observar que el comportamiento a cortante tras la fisuración del hormigón es complejo y ha sido tradicionalmente abordando con modelos empíricos, que desprecian algunos efectos o que han sido calibrados hace décadas y para situaciones específicas. Por ello, tales modelos y expresiones, en general, no son directamente aplicables a casos diferentes a aquellos para los que fueron derivados. Debido a estas limitaciones se han desarrollado modelos teóricos que tratan de cuantificar las distintas componentes de la contribución del hormigón. Entre ellos el modelo, “Compresion Chord Capacity Model” (CCCM), derivado a partir de uno más general (Multi-action shear model, MASM) previamente desarrollado por los mismos autores, incorpora las contribuciones de la cabeza de compresión del hormigón, el alma fisurada, el efecto pasador de las armaduras y el refuerzo de corte en una expresión compacta. El carácter mecánico del modelo proporciona información valiosa sobre la física del problema e incorpora los parámetros más relevantes que rigen la resistencia al corte de los elementos de hormigón estructural. El objetivo de este trabajo final de master es estudiar, mediante verificaciones experimentales sistemáticas, la precisión de la formulación del modelo CCCM y contribuir a su mejora. Para ello, en primer lugar, se ha tratado de identificar experimentalmente los valores de dos parámetros del modelo, la posición de inicio y la inclinación de la fisura

The first, and probably the most determining, decision that structural designing teams need to make when facing the design of any infrastructure is the choice of both an appropriate material and the suitable structural typology for its components. Each component is required to satisfy those technical and functional aspects imposed by the standards and stakeholders. However, basing the decision only on these criteria does not always lead to unambiguous solutions. Currently, the aspects that are most frequently considered in decision-making processes are economic. Nevertheless, environmental and social criteria are also mandatory if one aims at making sustainability-based decisions. In this regard, from the authors’ knowledge, no tools or studies that could support decision-makers in these aspects have been found into the scientific literature and, if any, these turn to be inoperative or barely representative for the purpose since the great majority of these are oriented to building’s sustainability assessment. Therefore, the aim of the present research paper is to develop a new method for the sustainability analysis of building structural components which has been specifically oriented to beams and girders. This is done by means of a method, MIVES, that draws on multi-attribute utility theory and that allows building an integrated value model as an approach for multi-criteria decision-making. The developed model has been applied to assess the sustainability of different alternatives of beams and trusts to support the non-accessible roof of a sports halls in Vila-seca, Spain. Different material types and structural typologies are analysed. The findings show that the most sustainable alternatives are timber and reinforced concrete trusses, which are actually two options that are seldom used in practice., Peer Reviewed, Postprint (author's final draft)

[ES] El objetivo es construir y caracterizar una viga tipo mecano con aluminio laminado. Caracterizando el material compuesto y la viga., [EN] The objective is to build and characterize a mecha type beam with laminated aluminum. Characterizing the composite material and the beam.

[ES] El objetivo es construir y caracterizar una viga tipo mecano con aluminio laminado. Caracterizando el material compuesto y la viga., [EN] The objective is to build and characterize a mecha type beam with laminated aluminum. Characterizing the composite material and the beam.

[ES] El objetivo es construir y caracterizar una viga tipo mecano con aluminio laminado. Caracterizando el material compuesto y la viga., [EN] The objective is to build and characterize a mecha type beam with laminated aluminum. Characterizing the composite material and the beam.

El present treball té com a objectiu trobar una sol·lució, realitzable des del punt de vista teòric, i raonable des del punt de vista econòmic i tecnològic, per a poder reforçar provisionalment ponts de fins a uns 50 m de llum, la qual cosa significaría doblar la capacitat actual que hi ha usant bigues saltadores. La solució proposada, mitjançant bigues saltadores amb pretensat extradosat, és el resultat de combinar els conceptes i filosofia de bigues saltadores, pretensat exterior i pretensat extradosat.

La resistencia a cortante de vigas o losas sin armadura transversal depende en gran medida de la profundidad de la zona no fisurada, la cual es capaz de resistir altas tensiones tangenciales debido a las compresiones procedentes de la flexión. Por tanto, si se necesita reforzar una viga o losa frente a cortante, en lugar de disponer cercos podría introducirse armadura longitudinal de flexión que aumentase el valor de la profundidad de la fibra neutra en flexión “x”. Se utilizará el Multiaction shear model como modelo de trabajo.

Este trabajo pretende estudiar el comportamiento a cortante de vigas de vigas en T reforzadas con polímeros reforzados en forma de U. Para ello se realizará una modelización numérica de unos ensayos realizados en el laboratorio de tecnología de estructuras y se compararán los resultados numéricos con los obtenidos de la instrumentación empleada en los ensayos.

In the late 19th century, Belgian engineer Jules Arthur Vierendeel registered the patent for a new type of beam. This would be later on better known as the Vierendeel truss. It is characterized by the frame’s lack of diagonal members, something which would appear to contradict conditions of steadiness and balance, along with its notable deformation and difficult calculation, caused technicians in his time to be skeptical about its applicability. Nevertheless, its application surged in popularity during the 20th century, being used both in civil engineering and architecture. What are the advantages of the Vierendeel truss as compared to other types, such as diagonal trusses? In this article, the Vierendeel typology will be introduced along with its main features, its calculation as well as its implementation in civil engineering and architectural works., Postprint (published version)

La resistencia a cortante de vigas o losas sin armadura transversal depende en gran medida de la profundidad de la zona no fisurada, la cual es capaz de resistir altas tensiones tangenciales debido a las compresiones procedentes de la flexión. Por tanto, si se necesita reforzar una viga o losa frente a cortante, en lugar de disponer cercos podría introducirse armadura longitudinal de flexión que aumentase el valor de la profundidad de la fibra neutra en flexión "x". Se utilizará el Multiaction shear model como modelo de trabajo.

A novel repair method has been developed at the University of Connecticut for corroded steel bridge girder ends. The repair method consists of encasing the corroded steel area with UHPC. The UHPC panel is bonded to the steel girder using headed shear studs welded to the uncorroded portions of the thin web. The repair provides a secondary load path to restore the bearing and shear strength of the girder which were reduced due to corroded section loss. The interaction between the headed shear studs, web plate and UHPC cast is the focal point of the proposed UHPC repair method. Welding headed shear studs to the thin web plate of a bridge girder is not traditional practice. A comprehensive performance evaluation of the shear connectors is needed when they are welded on thin web plates and embedded in UHPC. This report presents the six-phase approach to generate a thorough understanding of this critical force-transfer mechanism so that the bridge repair may be successfully implemented. A series of 38 push-out experiments and several supplemental finite element simulations were conducted to understand various design considerations on a local level. The five phases include 1) developing a general understanding of the behavior of head shear studs embedded in UHPC through a parametric study, 2) evaluating design considerations such as effect of eccentric loading, surface preparation, and UHPC conditions, 3) performing finite element analysis to validate experimental results, 4) analyzing the durability of the repair, 5) evaluating the potential of using alternative shear connectors, and 6) developing design guidelines for shear connectors for the UHPC repair.

Rapid economic and population growth, along with deteriorating bridge infrastructure, is putting a persistent strain on the nation's transportation network. Federal and state transportation departments (DOTs) are looking for new ways to build, repair, or replace bridges quickly and with minimal interruption to the traveling public. The FHWA has begun an attempt to shorten the time it takes to put new bridges into operation and to increase the design life of bridges from 50 to 75 years. In response to these changes and to facilitate accelerated bridge construction (ABC) practices, several State Departments of Transportation (DOTs), including Alabama DOT (ALDOT), have developed a variety of structural connection details for prefabricated bridge elements ranging from full-depth precast deck panels to precast girders to precast integral abutments.

En el presente trabajo de fin de grado se desarrolla un software para calcular las torsiones a las que se ve sometida una viga continua. Es decir, se resuelve el problema de una viga continua sometida a torsión en su caso general y, por tanto, incluyendo la torsión uniforme y de alabeo. El desarrollo del software se basa en la aplicación del método directo de la rigidez siendo necesaria la obtención de la matriz de rigidez de un elemento de viga sometida a torsión general. La obtención de las leyes de esfuerzos, en este caso, torsor uniforme, torsor de alabeo, torsor total y bimomento, necesitan de las correspondientes expresiones derivadas de la solución de la ecuación diferencial de la torsión. El método se implementa mediante Visual Basic con una interfaz en Excel, para la entrada de datos y la salida de resultados. Una vez desarrollado, se ha verificado dicho programa mediante dos pruebas diferentes. La primera verificación se basa en la creación de cuatro casos particulares para los cuales se ha hallado su solución exacta (analítica) para, posteriormente, comparar dicha solución a los resultados del software. La segunda verificación se desarrolla a partir de un determinado ejercicio resuelto, obtenido de la literatura, con unas características de viga concretas, las cuales se introducirán en el software para comparar que los resultados de este se corresponden a los resultados del ejercicio resuelto. En el CD se incluye el software implementado en Microsoft Excel para los alumnos de la EEBE que estén interesados en las vigas continuas sometidas a torsión.

En este trabajo se modeliza mediante la combinación del metodo de elementos finitos (FEM) y el método del elemento discreto (DEM) los ensayos realizados en el Laboratorio de Tecnología de estructuras Luis Agulló sobre elementos prismáticos sometidos a tracción indirecta para estudiar el efecto tamaño en la zona de compresión de elementos sometidos a esfuerzo cortante.

[EN] Writing project for repair and structural reinforcement of the floors of a residential building . These floors were made with ceramic beams , widely used in the 40s this project is intended to define the necessary measures to strengthen the stability of the building repairing damaged beams and reinforcing that are located in wetlands works. current legislation is studied in the project report regarding restricting the use of steel in construction and type of joist detailed work ., [ES] Redacción de proyecto para reparación y refuerzo estructural de los forjados de un edificio de viviendas. Estos forjados se realizaron con viguetas cerámicas, muy utilizadas en los años 40. Se pretende con este proyecto definir las obras necesarias para consolidar la estabilidad del edificio reparando las viguetas deterioradas y reforzando las que se encuentran ubicadas en zonas húmedas. Se estudia en la memoria del proyecto la normativa vigente en cuanto a restricción del uso de acero en edificación y se detalla el tipo de vigueta de la obra.

[EN] Writing project for repair and structural reinforcement of the floors of a residential building . These floors were made with ceramic beams , widely used in the 40s this project is intended to define the necessary measures to strengthen the stability of the building repairing damaged beams and reinforcing that are located in wetlands works. current legislation is studied in the project report regarding restricting the use of steel in construction and type of joist detailed work ., [ES] Redacción de proyecto para reparación y refuerzo estructural de los forjados de un edificio de viviendas. Estos forjados se realizaron con viguetas cerámicas, muy utilizadas en los años 40. Se pretende con este proyecto definir las obras necesarias para consolidar la estabilidad del edificio reparando las viguetas deterioradas y reforzando las que se encuentran ubicadas en zonas húmedas. Se estudia en la memoria del proyecto la normativa vigente en cuanto a restricción del uso de acero en edificación y se detalla el tipo de vigueta de la obra.

[EN] Writing project for repair and structural reinforcement of the floors of a residential building . These floors were made with ceramic beams , widely used in the 40s this project is intended to define the necessary measures to strengthen the stability of the building repairing damaged beams and reinforcing that are located in wetlands works. current legislation is studied in the project report regarding restricting the use of steel in construction and type of joist detailed work ., [ES] Redacción de proyecto para reparación y refuerzo estructural de los forjados de un edificio de viviendas. Estos forjados se realizaron con viguetas cerámicas, muy utilizadas en los años 40. Se pretende con este proyecto definir las obras necesarias para consolidar la estabilidad del edificio reparando las viguetas deterioradas y reforzando las que se encuentran ubicadas en zonas húmedas. Se estudia en la memoria del proyecto la normativa vigente en cuanto a restricción del uso de acero en edificación y se detalla el tipo de vigueta de la obra.

La presente investigación tiene como propósito comparar la capacidad última de conectores de cortante tipo espigo con cabeza (stud) con los conectores de cortante tipo perno, en losa de concreto vaciado sobre tablero metálico, los cuales junto con la viga de acero conforman sección compuesta -- Dicha comparación se realizó a partir de los resultados obtenidos de las pruebas de corte directo, push out, realizadas a probetas -- Estas consistieron en dos placas de concreto vaciado sobre tablero metálico, unidas mediante un perfil de acero, logrando una probeta simétrica -- Para realizar la fijación de los elementos indicados se utilizaron conectores de cortante, soldados al eje del ala del perfil -- Todos en posición débil -- Se utilizaron tres probetas con conector tipo espigo con cabeza y tres probetas con conector tipo perno -- Se elaboraron gráficas de carga versus desplazamiento -- Se determinó la capacidad promedio por cada grupo de tipo de conector -- Se obtiene el cociente entre la capacidad promedio del conector tipo espigo sobre la capacidad promedio del conector tipo perno, dando como resultado una variación del 4 %, por lo que se concluye que es equivalente usar el uno o el otro

Large displacement analysis of beams has been investigated extensively during the past decades. Many beam element formulations have been studied and proposed for this purpose. The efficiency is gradually improved in such a way that later beam elements are capable of giving better accuracies by using smaller numbers of degrees of freedom. This subsequently results in saving of time and effort needed in large displacement analysis of beams. In this study, a new 2D field-consistent Bézier beam element for large displacement analysis is proposed. The interpolation functions of the proposed element are constructed by using a rational Bézier curve to represent the geometry of the element. The interpolation functions are constructed in such a way that the consistency among the unknown fields is obtained. The formulation of the proposed element is based on the total Lagrangian description. A rational Bézier curve is used instead of polynomials in order that complex configurations of beams can be accurately reproduced using small numbers of elements. The employed field-consistent interpolations increase the performance of the element and remove the problem of shear locking. The proposed beam element is tested by several benchmark problems and the results are found to be satisfactory.

Large displacement analysis of beams has been investigated extensively during the past decades. Many beam element formulations have been studied and proposed for this purpose. The efficiency is gradually improved in such a way that later beam elements are capable of giving better accuracies by using smaller numbers of degrees of freedom. This subsequently results in saving of time and effort needed in large displacement analysis of beams. In this study, a new 2D field-consistent Bézier beam element for large displacement analysis is proposed. The interpolation functions of the proposed element are constructed by using a rational Bézier curve to represent the geometry of the element. The interpolation functions are constructed in such a way that the consistency among the unknown fields is obtained. The formulation of the proposed element is based on the total Lagrangian description. A rational Bézier curve is used instead of polynomials in order that complex configurations of beams can be accurately reproduced using small numbers of elements. The employed field-consistent interpolations increase the performance of the element and remove the problem of shear locking. The proposed beam element is tested by several benchmark problems and the results are found to be satisfactory.

Large displacement analysis of beams has been investigated extensively during the past decades. Many beam element formulations have been studied and proposed for this purpose. The efficiency is gradually improved in such a way that later beam elements are capable of giving better accuracies by using smaller numbers of degrees of freedom. This subsequently results in saving of time and effort needed in large displacement analysis of beams. In this study, a new 2D field-consistent Bézier beam element for large displacement analysis is proposed. The interpolation functions of the proposed element are constructed by using a rational Bézier curve to represent the geometry of the element. The interpolation functions are constructed in such a way that the consistency among the unknown fields is obtained. The formulation of the proposed element is based on the total Lagrangian description. A rational Bézier curve is used instead of polynomials in order that complex configurations of beams can be accurately reproduced using small numbers of elements. The employed field-consistent interpolations increase the performance of the element and remove the problem of shear locking. The proposed beam element is tested by several benchmark problems and the results are found to be satisfactory.

La presente investigación tiene como propósito comparar la capacidad última de conectores de cortante tipo espigo con cabeza (stud) con los conectores de cortante tipo perno, en losa de concreto vaciado sobre tablero metálico, los cuales junto con la viga de acero conforman sección compuesta -- Dicha comparación se realizó a partir de los resultados obtenidos de las pruebas de corte directo, push out, realizadas a probetas -- Estas consistieron en dos placas de concreto vaciado sobre tablero metálico, unidas mediante un perfil de acero, logrando una probeta simétrica -- Para realizar la fijación de los elementos indicados se utilizaron conectores de cortante, soldados al eje del ala del perfil -- Todos en posición débil -- Se utilizaron tres probetas con conector tipo espigo con cabeza y tres probetas con conector tipo perno -- Se elaboraron gráficas de carga versus desplazamiento -- Se determinó la capacidad promedio por cada grupo de tipo de conector -- Se obtiene el cociente entre la capacidad promedio del conector tipo espigo sobre la capacidad promedio del conector tipo perno, dando como resultado una variación del 4 %, por lo que se concluye que es equivalente usar el uno o el otro

Preprint

Preprint

El diseño de elementos sometidos a esfuerzos cortantes ha generado numerosos debates ya que las formulaciones actuales, incluidas las propuestas en las normativas actuales como EHE-08, EC-2 y ACI 318-011, no acaban de obtener buenos resultados cuando se comparan con resultados experimentales. Un aspecto concreto muy relevante, asociado a la forma de rotura de los materiales cuasi-frágiles como el hormigón, es el fenómeno conocido como efecto tamaño, que da lugar a que la tensión tangencial media resistida por una viga sea menor a medida que aumenta su tamaño. A pesar de las numerosas investigaciones experimentales, no existe consenso sobre cómo abordarlo ni cómo plasmarlo en una formulación simple para diseño. En esta Tesis se aborda el estudio del efecto tamaño en vigas de hormigón armado, mediante modelización numérica por el Método de los Elementos Finitos, incluyendo el comportamiento no lineal de los materiales y fractura el hormigón a tracción. En primer lugar se han reproducido los ensayos a mayor escala realizados en el mundo (Universidad de Toronto) y se han calibrado los parámetros del modelo numérico. A partir de ahí se han simulado ensayos sobre vigas con distinto tamaño, esbeltez a cortante, y cuantías de armadura longitudinal y transversal. Los resultados permiten detectar el efecto tamaño y la influencia de las citadas variables en la resistencia a cortante de las vigas estudiadas. El presente trabajo se ha enmarcado en un proyecto de investigación sobre evaluación de la resistencia a esfuerzo cortante de estructuras existentes de hormigón armado y pretensado, actualmente en desarrollo en el Departamento de Ingeniería Civil y Ambiental de la UPC.