Rozprawy doktorskie na temat „FRCS”

This report is a thesis for the Technicians in Computer Aided Design program at Halmstad University. The group has developed a milling machine mainly used for fiber boards, on behalf of Johan Wretborn.

Music Education
Ph.D.
The purpose of this research was to examine the potential relationship between students’ degree of familiarity with repertoire common to beginning band method books and aural-based music achievement after one year of study. Three research questions guided this study: (1) Which songs from the Familiar Repertoire Survey (FRS) are reported as being the most and least familiar to the sample? (2) For a familiar song, “Lightly Row,” can FRS scores predict (a) Familiar Music Achievement Singing Test (FMAST) scores, (b) Familiar Music Achievement Playing Test (FMAPT) scores, (c) Familiar Music Achievement Improvisation Singing Test (FMAIST) scores, and (d) Familiar Music Achievement Improvisation Playing Test (FMAIPT) scores? (3) For an unfamiliar song, “Finish Line,” can FRS scores predict (a) Unfamiliar Music Achievement Singing Test (UMAST) scores, (b) Unfamiliar Music Achievement Playing Test (UMAPT) scores, (c) Unfamiliar Music Achievement Improvisation Singing Test (UMAIST) scores, and (d) Unfamiliar Music Achievement Improvisation Playing Test (UMAIPT) scores? Participants (N = 17) were fifth and sixth grade students enrolled in their second year of beginning band in a New Jersey elementary school. I created two measurement instruments: FRS, designed to gauge the breadth and depth of students’ familiarity with songs common to beginning band method books, and the Music Achievement Test (MAT) designed to measure aural-based music achievement in singing, playing by ear, and improvising on a familiar and unfamiliar song. In the first session, participants completed FRS by listening to songs common to beginning band books and completing a Likert-type survey on their familiarity with each song. Later, participants watched MAT through an interactive video which prompted them to complete eight musical subtests. I recorded all performances. Judges rated each performance with two rating scales. I analyzed the frequency of responses for each song and found “Hot Cross Buns,” “Jingle Bells,” “Pierrot,” “Lightly Row,” and “London Bridge” to be the most familiar songs. Through linear regressions, I analyzed the ability of FRS to predict MAT scores. I found a significant regression equation between FRS and its ability to predict FMAST scores and UMAIST scores. The current exploratory study contained many limitations which restricts its generalizability to other beginning band populations; however, six conclusions can be made. Familiarity with common beginning band repertoire as represented by a selection of 24 songs common to beginning band method books does not predict students’ achievement (a) singing an unfamiliar song, (b) demonstrating through singing improvisation based on a familiar song, (c) playing by ear a familiar or unfamiliar song, and (d) improvising on an instrument, whether improvising within the context of a familiar or unfamiliar song. Familiarity with common beginning band repertoire does predict students’ achievement (a) singing a familiar song and (b) demonstrating through singing improvisation based on an unfamiliar song.
Temple University--Theses

Sono sempre di più le città alla ricerca di uno sviluppo sostenibile delle politiche e degli strumenti volti a garantire un’efficiente ed efficace mobilità urbana per passeggeri e merci. Oggigiorno, il veicolo maggiormente utilizzato per il trasporto merci è il camion, il quale influisce sull’aumento del traffico urbano, sul numero di incidenti e sull’emissione di sostanze inquinanti. In questo testo si propone un metodo alternativo per il trasporto della merce, utilizzando la rete ferroviaria urbana come soluzione potenziale per decrementare l’inquinamento atmosferico e per ridurre il flusso stradale spostandolo su quello ferroviario. Il problema trattato si chiama Freight Rail Transport Scheduling (FRTS), ovvero la pianificazione del trasporto della merce per ferrovia. Si tratta della condivisione comune della rete ferroviaria urbana per trasportare i passeggeri e la merce. In particolare, si tratta di assegnare le domande dei clienti a treni appartenenti ad una linea ferroviaria, dove ogni stazione può essere utilizzata come piattaforma per lo scarico/carico della merce. L’obiettivo è la minimizzazione del tempo totale d’attesa delle merci nelle stazioni per massimizzare il turnover della merce. Poiché il problema è di tipo NP-difficile, si propone un Algoritmo Genetico (AG) come metodo risolutivo. L’algoritmo è costituito da una lista di individui, identificati da una serie di domande ordinate in base alla priorità di assegnazione ai treni. La soluzione ricercata è una lista di treni a cui sono state assegnate le domane dei clienti. Gli operatori principali dell’algoritmo sono il crossover e la mutazione, i quali permettono di trovare la soluzione ottima o sub-ottima. In aggiunta, verrà presentato un caso pratico di implementazione dell’algoritmo per trasportare pacchi nella città di Parigi, utilizzando la linea 14 della metropolitana. Le emissioni di CO2 verranno poi calcolate e valutate per l’attuale e per l'alternativo modo di trasporto

Nella presente Tesi è affrontata l’analisi sperimentale e teorica del comportamento di pareti in muratura rinforzate con FRCM e sollecitate da azioni di taglio fuori piano. Lo schema statico adottato per i campioni sperimentati consiste in uno schema appoggio-appoggio, mentre le forze esterne di taglio sono state applicate secondo uno schema di carico a quattro punti. Durante il corso della prova, i pannelli murari sono inoltre stati soggetti ad un carico di precompressione verticale costante, che simula l’effetto della presenza del solaio in un edificio in muratura. Dopo una descrizione teorica delle principali caratteristiche dei materiali compositi e dei loro costituenti, all’interno della Tesi sono richiamati alcuni studi scientifici relativi al comportamento fuori piano di elementi strutturali rinforzati con FRCM. In seguito vengono presentati i materiali impiegati per la campagna sperimentale e le prove di caratterizzazione meccanica eseguite. Vengono poi riportati i risultati sperimentali delle prove a taglio fuori piano in termini di spostamenti, di deformazioni e di scorrimenti, affrontando infine un confronto tra i risultati ottenuti per i campioni esaminati e riportando alcune considerazioni circa la strumentazione impiegata. L’ultima parte della Tesi è dedicata all’analisi teorica delle pareti. Viene proposto un modello teorico per stimare la resistenza fornita dai muri rinforzati, ipotizzando tre possibili modalità di rottura: rottura a trazione della fibra, rottura per distacco tra FRCM e supporto in muratura e rottura per delaminazione interna. Infine, viene riportata la modellazione agli elementi finiti svolta mediante il codice di calcolo MidasFea, che consente di attribuire ai materiali legami costitutivi adeguati per la modellazione di strutture in muratura, cogliendone il comportamento non lineare e il progressivo danneggiamento.

Le but de cette thèse est de proposer une solution efficace pour améliorer les performances des applications Web. Les systèmes d’accélération visent, en particulier, à résoudre ce problème. Le système que nous proposons s’appelle FRACS. L’idée centrale de FRACS est de fragmenter les applications Web, identifier les fragments réplicables, et les répliquer dynamiquement avec les tables de la base de données qu’ils accèdent, en vue de générer le contenu dynamique demandé au niveau du réseau. FRACS cache également le résultat d’exécution des fragments lorsque cela est possible pour accélérer la génération du contenu dynamique. FRACS a principalement quatre majeures contributions. D’abord, il fournit un module qui fragmente automatiquement le code des applications Web d’une manière statique. Les filtres représentent également une contribution intéressante de FRACS. En plus d’identifier le contenu généré d’une manière unique, les filtres permettent de déterminer les identificateurs des fragments nécessaires à la construction d’une page, même si l’URL exacte de cette page n’a pas été accédée. Une autre contribution de notre travail réside dans les protocoles de cohérence proposés pour les fragments de contenu cachés et les bases de données partiellement répliquées. Enfin contrairement aux CDNs existants, FRACS permet aux fournisseurs de contenu d’adapter les politiques de réplication du CDN aux besoins spécifiques de leurs applications, ainsi que de maîtriser leur utilisation des ressources du CDN.

Interventions for strengthening, repairing, and upgrading of existing reinforced concrete (RC) structures are aimed to increase/restore their structural capacity to withstand flexural, shear, torsional, and axial loads. Reasons to carry out such interventions vary from the need to upgrade the structure to current guidelines, overcome design and construction mistakes, and allow an increment in load due to a change in use. In addition, unexpected overloading events, such as earthquakes, might damage the structure, reducing its original performance. The same behavior can be expected in the case of fire or lack of adequate maintenance. In the previous decades the use of fiber reinforced polymer (FRP) composites has gained worldwide popularity to carry out such interventions due to some of their properties such as high strength-to-weight ratio, ease of application, and good corrosion resistance. However, the use of organic resin matrix in FRP composites has been associated with some limitations of their use such as inability to apply onto wet surfaces, low resistance to relatively high temperatures, and difficulty to carry out post-earthquake assessment. For this reason, in recent years, an important research effort has been developed in order to study composites known as fiber reinforced cementitious matrix (FRCM) composites, in which the organic resin is replaced by an inorganic matrix. In this thesis, the behavior of RC beams strengthened in shear with externally bonded FRCM composites is studied. The first part of this thesis summarizes the state of research on the topic of shear strengthening of RC beams using externally bonded FRCM composites with the goal of serving as a reference point for the development of future research. A detailed bibliographical review of the literature on the shear strengthening of RC beams using FRCM composites is carried out, and the major findings and main aspects that should be addressed in future research are indicated. The collected experimental evidence shows that FRCM composites are able to increase the shear strength of RC beams, modifying in some cases the type of failure from shear to a flexural mode. Then, the results of an experimental campaign on shear strengthening of RC beams with externally bonded FRP and FRCM composites are presented. FRP and FRCM composites with two different fiber types are examined. Two different stirrup spacings were employed to investigate the internal-external shear reinforcement interaction. Considering the limited experimental evidence on the use of anchors for RC beams strengthened in shear with FRCM composites, the performance of FRCM strengthened beams with and without anchors is also compared. Results show that the effectiveness of the FRCM system depends on the spacing of theinternal shear reinforcement. In addition, internal-external shear reinforcement interaction was witnessed, but the intereaction appears to be less pronounced than in beams strengthened with FRP composites. Design models proposed to predict the contribution of the FRCM composite to the shear strength of RC beams are assessed using the database of experimental results collected and compiled by the author and the experimental results included in this thesis. Results show that the performance of the models is highly influenced by the type of failure mode attained by the strengthened beams. In addition, the use of the FRCM composite properties instead of the bare fiber mechanical characteristics does not result in an increase in the accuracy of the models. Strains measured by strain gauges mounted onto the internal (stirrups) and external (FRCM system) transverse reinforcement of the tested beams are used to compute the individual contributions of the concrete, steel, and fibers to the overall shear strength of the FRCM strengthened beams, and to study the possible interaction among them. It was found that the concrete contribution to the shear resistance starts to decrease after first cracking of the concrete is achieved. After this point, the stirrup and fiber contributions start to increase until the peak load is attained. Lastly, a new analytical model based on the bond behavior of the FRCM composites applied onto concrete substrates is introduced and discussed. Although additional tests are required to calibrate the model, initial results show that the assumptions and hypothesis used during its development are appropriate.
Gli interventi per il rafforzamento e la riparazione delle strutture esistenti in calcestruzzo armato mirano ad aumentare e ripristinare la loro capacità strutturale per resistere a carichi flessionali, a taglio, torsionali e assiali. I motivi per fare tali interventi variano dalla necessità di aggiornare la struttura alle linee guida attuali, superare gli errori di progettazione e costruzione e consentire un incremento del carico a causa di un cambiamento nell'uso. Inoltre, eventi di sovraccarico inaspettati, come terremoti, potrebbero danneggiare la struttura, riducendo le prestazioni originali. Lo stesso comportamento può essere previsto in caso d’incendio o mancanza di manutenzione adeguata. Nei decenni precedenti l'uso di compositi polimerici rinforzati con fibre (FRP) ha guadagnato popolarità in tutto il mondo per fare tali interventi a causa di alcune delle loro proprietà come il rapporto tra forza-peso, facilità di applicazione e buona resistenza alla corrosione. Tuttavia, l'uso della matrice di resina organica dei compositi FRP è stato associato ad alcune limitazioni del loro uso, come l'incapacità di applicare su superfici bagnate, bassa resistenza a temperature relativamente alte e difficoltà nella valutazione post-terremoto. Per questo motivo, negli ultimi anni, è stato sviluppato un importante sforzo di ricerca per lo studio di compositi noti come compositi a matrice cementizia fibrorinforzata (FRCM), in cui la resina organica viene sostituita da una matrice inorganica. In questa tesi, è studiato il comportamento de travi di calcestruzo armato rafforzate a taglio con compositi FRCM. La prima parte di questa tesi riassume lo stato della ricerca sul tema del rinforzo a taglio delle travi RC utilizzando compositi FRCM con legami esterni con l'obiettivo di servire come punto di riferimento per lo sviluppo della ricerca futura. Viene effettuata una revisione bibliografica dettagliata della letteratura sul rafforzamento a taglio delle travi utilizzando i compositi FRCM, e vengono indicati i principali risultati e gli aspetti principali che dovrebbero essere affrontati nelle ricerche future. Le prove sperimentali raccolte mostrano che i compositi FRCM sono in grado di aumentare la resistenza al taglio delle travi, modificando in alcuni casi il tipo di cedimento da taglio a una modalità a flessione. Quindi, sono presentati i risultati di una campagna sperimentale sul rinforzo a taglio di travi con compositi FRP e FRCM. Vengono esaminati i compositi FRP e FRCM con due diversi tipi di fibre. Sono state impiegate due diverse spaziature delle staffe per studiare l'interazione di rinforzo di taglio interno-esterno. Considerando le limitate prove sperimentali sull'uso di elementi di ancoraggio travi rinforzate a taglio con materiali compositi FRCM, viene anche confrontata la prestazione di travi rinforzate FRCM con e senza ancoraggi. I risultati mostrano che l'efficacia del sistema FRCM dipende dalla spaziatura del rinforzo del taglio interno. Inoltre, è stata osservata l'interazione di rinforzo di taglio interno-esterno, ma l'interazione sembra essere meno pronunciata rispetto alle travi rinforzate con compositi FRP. I modelli di progettazione proposti per prevedere il contributo del composito FRCM alla resistenza al taglio delle travi sono valutati utilizzando il database dei risultati sperimentali raccolti e compilati dall'autore e i risultati sperimentali inclusi in questa tesi. I risultati mostrano che le prestazioni dei modelli sono fortemente influenzate dal tipo di modalità di rottura raggiunta. Inoltre, l'uso delle proprietà dei compositi FRCM al posto delle caratteristiche meccaniche delle fibre non comporta un aumento dell'accuratezza dei modelli. Le deformazioni misurati dagli estensimetri montati sulle armature interne (staffe) e esterne (sistema FRCM) delle travi sottoposte a prova vengono utilizzati per calcolare i singoli contributi del calcestruzzo, dell'acciaio e delle fibre alla resistenza complessiva al taglio delle travi rinforzate con i compositi FRCM, e per studiare la possibile interazione tra loro. Si è costatato che il contributo concreto alla resistenza al taglio inizia a diminuire dopo il primo crollo del calcestruzzo. Dopo questo punto, i contributi della staffa e della fibra iniziano ad aumentare fino al raggiungimento del picco di carico. Infine, è introdotto e discusso un nuovo modello analitico basato sul comportamento del legame dei compositi FRCM applicati su substrati in calcestruzzo. Sebbene siano necessari successivi test per calibrare il modello, i risultati iniziali mostrano che le ipotesi utilizzate durante il suo sviluppo sono appropriate.

Facial Recognition Systems är något som har blivit populärt de senaste åren, speciellt efter den 11 september 2001. Möjligheten att kunna över-vaka personer som rör sig i olika miljöer har varit av intresse för bland annat regeringar, till exempel USA:s regering. Eftersom det finns mängder med olika typer av undersökningar och alla försöker göra så bra matchningar som möjligt av personer mot databaser, fast de utförs på olika sätt, är det intressant att se om det finns någon parameter som har en större påverkan på resultaten, oavsett om undersökningen görs med 2D, 3D eller en kombination av metoderna. Det finns många olika faktorer och parametrar som påverkar matchningsprocenten därför skall denna littera-turstudie försöka lokalisera och se om det finns någon parameter som har en större påverkan på matchningsprocenten. Det visar sig att två parametrar har en större påverkan än övriga parametrar. De är antalet bilder av varje objekt som finns att matcha i databasen och kvaliteten på indata vilket innebär kontrast och upplösning samt hur kompletta ansiktena är.
Facial Recognition Systems is something that has become popular in recent years, especially after 11 September 2001. The ability to monitor people that are moving in different environments has been of interest to particular governments, for instance the US government. Since there are a lot of different types of surveys, though performed in different ways, all trying to do the best matches of people to databases as possible, it is interesting to see if there is any parameter that has a major impact on the result. Whether the survey is done with 2D, 3D or a combination of methods, there are many different factors and parameters that affect the matching percentage. Therefore this study tries to locate and see if there is any parameter that has a greater impact on the matching percentage. It appears that two of the parameters have a greater effect on the result, than the others. These are the number of images of a test subject in the database and the quality of the input data. The quality is defined by contrast and resolution as well as how complete the faces are.

Le tipologie di prova adottate durante i test condotti su campioni FRCM sono state essenzialmente due: prove di trazione e prove di aderenza, svolte impiegando due diverse modalità di applicazione del carico (caricamento monotono e/o ciclico) e due diverse tipologie di rinforzo (una in fibra di carbonio e una in fibra di vetro). Nel corso delle prove di trazione, i risultati migliori sono stati ottenuti per i rinforzi in fibra di carbonio con applicazione del carico di trazione monotona, quindi per la soluzione in cui si è utilizzata la fibra avente le caratteristiche meccaniche migliori; il comportamento di questi materiali è risultato tuttavia peculiare, in quanto lo strato di malta esterno ha mostrato spesso distacchi e perdita di adesione rispetto alla rete bidirezionale di rinforzo, rendendo difficoltosa la misura esterna della deformazione del composito. I rinforzi in fibra di vetro (GFRCM) hanno mostrato risultati inferiori in termini di tensione massima, in accordo con la tipologia di fibra impiegata, ma hanno evidenziato un comportamento caratterizzato si dall’apertura di fessure, ma maggiormente assimilabile ad una schematizzazione trilineare, senza fenomeni evidenti di distacco esterno della matrice prima della rottura. Dalla sperimentazione dei provini mediante prove di aderenza è emerso che, sia nel caso di prove monotone che cicliche, i provini rinforzati con GFRCM hanno mostrato un’efficienza maggiore. La rete in fibra di vetro ha mostrato una aderenza migliore all’interno della matrice cementizia, rispetto alla rete in fibra di carbonio, perché presenta uno speciale trattamento superficiale (appretto) che ne migliora la compatibilità e l’adesione al supporto. I rinforzi GFRCM testati hanno sfruttato al meglio le proprie caratteristiche meccaniche raggiungendo valori di carico maggiori (circa doppi) rispetto ai rinforzi CFRCM.

Mitt examensarbete handlar om den utfasade snickerimaskinen överfräsen. Maskinen försvann från verkstäderna för mer än 30 år sedan och den erfarenhetsbaserad kunskapen om hur den användes finns hos före detta verkmästare och arbetare. Genom platsbesök och intervjuer på verkstäder och föreningar dokumenterar jag den immateriella kunskap som inte går att finna i litteraturen. Jag kommer sedan själv göra praktiska tester på maskinen för att verifiera den nyvunna kunskapen men också för att undersöka om maskinen har några användingsområden i det moderna snickeriet.
My thesis explores the overhead router, a formerly common but now rarely used and largely forgotten milling machine. My methods will be both practical and theoretical, and I will linger on three main questions; (1) How is the overhead router used? (2) Why did workers and foremen stop using the overhead router? And (3) what are the potential advantages of the overhead router? The theoretical side of my work will be based on interviews and field research from various workshops and woodwork organizations. The practical aspect of my thesis is an attempt to learn to use the overhead router personally, and in doing so, find out if the overhead router has a place in the contemporary woodworking shop.

Unreinforced masonry (URM) walls are commonly found in existing and heritage buildings in Canada, either as infill or load-bearing walls. Such walls are vulnerable to sudden and brittle failure under blast loads due to their insufficient out-of-plane strength. The failure of such walls under blast pressures can also result in fragmentation and wall debris which can injure building occupants. Over the years, researchers have conducted experimental tests to evaluate the structural behaviour of unreinforced masonry walls under out-of-plane loading. Various strengthening methods have been proposed, including the use of concrete overlays, polyurea coatings and advanced fiber-reinforced polymer (FRP) composites. Fabric-reinforced cementitious matrix (FRCM) is an emerging material which can also be used to strengthen and remove the deficiencies in unreinforced masonry walls. This composite material consists of a sequence of one or multiple layers of cement-based mortar reinforced with an open mesh of dry fibers (fabric). This thesis presents an experimental and analytical study which investigates the effectiveness of using FRCM composites to improve the out-of-plane resistance of URM walls when subjected to blast loading. As part of the experimental program, two large-scale URM masonry walls were constructed and strengthened with the 3-plies of unidirectional carbon FRCM retrofit. The specimens included one infill concrete masonry (CMU) wall, and one load-bearing stone wall. The University of Ottawa Shock Tube was used to test the walls under gradually increasing blast pressures until failure, and the results were compared to those of control (un-retrofitted) walls tested in previous research. Overall, the FRCM strengthening method was found to be a promising retrofit technique to increase the blast resistance of unreinforced masonry walls. In particular, the retrofit was effective in increasing the out-of-plane strength, stiffness and ultimate blast capacity of the walls, while delaying brittle failure and reducing fragmentation. As part of the analytical research, Single Degree of Freedom (SDOF) analysis was performed to predict the blast behaviour of the stone load-bearing retrofit wall. This was done by computing wall flexural strength using Plane Section Analysis, and developing an idealized resistance curve for use in the SDOF analysis. Overall, the dynamic analysis results were found to be in reasonable agreement with the experimental maximum displacements.

In the last years, due to many severe seismic events, it becomes more and more important to understand the structural performance of masonry structures subjected to seismic actions and structural reinforce became an important task in civil engineering. The developments of innovative techniques for structural retrofitting represent a great change in order to reduce the seismic vulnerability of masonry buildings. Beside the traditional reinforce techniques, new reinforce born such as Fiber Reinforced Polymer (FRP) and Fiber Reinforced Cementitious Matrix (FRCM) The aim of this thesis is to study the shear strength of masonry panels, subjected to in-plane actions, reinforced with FRCM.

Nella tesi viene trattato il recupero delle strutture murarie tramite l’utilizzo di materiali compositi, in particolare si trattano i Fyber Reinforced Polymers (FRP) e i Fybers Reinforced Cementitious Matrix (FRCM). Ad oggi le principali tecniche di consolidamento si basano sull’utilizzo di materiali “classici”, come acciaio o cemento armato, dei quali esistono dettagliate indicazioni progettuali, ma che presentano la controindicazione di essere invasive e, quindi, di modificare il comportamento statico del sistema a cui vengono applicate. Utilizzando materiali compositi, invece, si possono ottenere importanti miglioramenti senza apportare cambiamenti statici, con l’ulteriore vantaggio di poter essere nascosti da intonaci. Prendendo come riferimento le normative in via di costituzione per la progettazione di interventi con FRCM, si sottolineano le principali differenze in termini di metodologie di verifica e di risultati tra i due materiali di interesse. L'obiettivo è quello suggerire delle indicazioni di riferimento utili al momento della selezione di un composito anziché l’altro. Si dimostra che è possibile realizzare interventi migliorativi sulla muratura con entrambi i materiali citati: a seconda della situazione risulteranno differenti le formule di verifica e gli ambiti in cui un composito è più indicato. Grazie alle caratteristiche di traspirabilità e permeabilità al vapore, oltre alla flessibilità che permette modeste deformazioni del supporto, i compositi FRCM sono particolarmente indicati all’applicazione su apparati murari. Tuttavia, non tutti i meccanismi di collasso possono essere recuperati equivalentemente con ambo i materiali, principalmente perché gli interventi con FRCM richiedono una maggiore superficie di applicazione.

La corrosion des armatures en acier est l'un des mécanismes les plus destructifs pour les structures en béton armé. La corrosion nuit non seulement à l'intégrité structurale et à l’aptitude au service de la structure endommagée, mais peut aussi entraîner des défaillances inattendues ou des ruptures fragiles. Malgré les dispositions rigoureuses de la plupart des codes de pratique pour éviter la corrosion, des signes de dommages dus à la corrosion sont toujours signalés. Récemment, des systèmes à matrice cimentaire renforcée de fibre (MCRF) ont été proposés comme une technique innovante de renforcement/réparation pour les structures en béton afin de surmonter les inconvénients associés à l'utilisation des systèmes de polymères renforcés de fibres (PRF). Bien que l'utilisation de composites MCRF pour renforcer les éléments en béton non endommagés ait prouvé son efficacité, très peu est connu sur la viabilité de leur utilisation pour renforcer les éléments en béton endommagés à divers niveaux dus à la corrosion. De plus, les comportements de post-réparation et la durabilité à long-terme des éléments corrodés et renforcés par les systèmes MCRF et qui seront probablement exposés aux mêmes conditions environnementales qui prévalaient avant leur réparation, n'ont pas retenu l'attention des chercheurs dans la littérature. De plus, la plupart de nos infrastructures, telles que les ponts et garages de stationnement, sont susceptibles d'être endommagées par la corrosion tout en étant soumises à des charges oscillatoires qui provoquent de la fatigue. À ce jour, aucune information n'est disponible sur l'effet de la combinaison de la charge de fatigue et de la corrosion dans les structures renforcées par les systèmes MCRF. Dans ce travail, les comportements monotones et de fatigue en flexion des poutres en béton endommagées par la corrosion et renforcées par des systèmes MCRF ont été étudiés en plus de leur performance à long-terme, c'est-à-dire après une exposition à un environnement corrosif après leur renforcement. Le travail comprend des investigations expérimentales et numériques. Les prédictions analytiques et les formulations théoriques actuellement disponibles dans les codes de conception ont été aussi vérifiées par rapport aux résultats expérimentaux. Le programme expérimental consistait à tester trente (30) poutres en béton à grande échelle de 150 × 250 × 2800 mm. Les poutres ont été construites et testées en configuration de charge à quatre points. Un processus accéléré de corrosion a été utilisé pour corroder les armatures d'acier en traction dans le tiers central des poutres. Les paramètres d'essai comprenaient le niveau de corrosion (représenté par 10, 20 et 30% de perte de masse dans l'acier de traction), le type de système de renforcement utilisé (Polyparaphénylène benzobisoxazole (PBO-MCRF), MCRF de carbone et PRF), la quantité de composites MCRF (1, 2, 3 et 4 couches), le schéma de renforcement MCRF (couches ancrées aux extrémités par rapport aux couches continues sous forme U) et le régime de chargement (monotone et fatigue). Les résultats des tests ont montré que l'utilisation de composites MCRF améliorait significativement le comportement en flexion des poutres corrodées. Les composites MCRF ont contrôlé le mode de défaillance des poutres renforcées plutôt que le niveau de corrosion des barres d'acier. Les poutres renforcées par la MCRF ont montré une augmentation de leurs résistances ultimes variant entre 7 et 65% de celles des poutres vierges (poutres ni corrodées ni renforcées) en fonction du type, de la quantité et du schéma de la MCRF utilisée. L'exposition des poutres réparées par la MCRF à d’autres cycles de corrosion a entraîné une réduction de 23% de la perte de masse de l'acier. Le schéma en U était plus efficace que le schéma d'ancrage aux extrémités à retarder le délaminage des couches de MCRF dans les poutres renforcées et testées à court terme. Il a également atténué l'effet des fissures de corrosion longitudinales et, par conséquent, a augmenté l'efficacité du renforcement MCRF. Les essais de fatigue ont montré que la corrosion des barres d'acier diminuait considérablement la résistance à la fatigue des poutres non renforcées. Le renforcement avec des composites MCRF a augmenté la durée de vie en fatigue des poutres endommagées par la corrosion de 38 à 377% de celle des poutres corrodées non-renforcées. Cependant, le renforcement par MCRF n'a pas restauré la durée de vie en fatigue des poutres vierges. Dans l'étude numérique réalisée dans ce travail, des modèles d'éléments finis (ÉF) tridimensionnels (3D) ont été développés pour simuler le comportement non linéaire des poutres corrodées et renforcées par des composites MCRF et PRF à l'aide du progiciel ATENA-3D. Les résultats de l'analyse numérique étaient en bon accord avec ceux obtenus expérimentalement en termes de modes de défaillance, de déformations, de capacités de charge et de flèches. Les modèles ÉF développés ont été capables de capturer le comportement non-linéaire des poutres testées avec une bonne précision. Une étude paramétrique a ensuite été menée pour étudier l'effet de la résistance à la compression du béton et de l'épaisseur de recouvrement des armatures sur l'efficacité de renforcement des systèmes composites. Il a été observé que la rupture des poutres renforcées par des FRCM était indépendante de la résistance à la compression du béton ou de l'épaisseur de de recouvrement et était régie uniquement par le glissement du tissu dans la matrice. Sur le plan analytique, les équations de conception de l’ACI-549.4R-13 (ACI 2013) ont été évaluées à l'aide des données expérimentales obtenues à partir des tests. Il a été conclu que les formulations théoriques de l’ACI-549.4R-13 peuvent raisonnablement prédire les résistances ultimes des poutres renforcées ancrées à l'extrémité mais sous-estimer celles des poutres ancrées en continu sous forme U. Un facteur de schéma de 1,1 a ensuite été proposé pour calculer la résistance nominale des poutres renforcées par MCRF sous forme U. Le résultat de ce travail a été publié (ou soumis pour publication) dans cinq articles de revues et cinq conférences, comme détaillé tout au long de la thèse.
Corrosion of steel reinforcement is one of the most destructive mechanisms for reinforced concrete (RC) structures. Corrosion not only impairs the structural integrity and the serviceability of the damaged structure, but it may also lead to unexpected and brittle failures. Despite the rigorous provisions of most codes of practice to avoid corrosion, evidences of corrosion damage are still being reported. Recently, fabric-reinforced cementitious matrix (FRCM) systems were proposed as an innovative strengthening/repair technique for RC structures to overcome the drawbacks associated with the use of the well-documented fiber-reinforced polymer (FRP) systems. While the use of FRCM composites to strengthen un-damaged RC members has proven its efficiency, very little is known about the viability of their use to retrofit RC members with various levels of corrosion damage. In addition, the post-repair performance and the long-term durability of the FRCM-strengthened corroded members, which most likely will be exposed to the same environmental conditions that have prevailed prior their repair, have not received attention in the literature. Moreover, most of our infrastructures such as bridges and parking garages are susceptible to corrosion damage while continuously being subjected to oscillatory loads that cause fatigue. To date, no information is available about the effect of combining fatigue loading with corrosion in FRCM-strengthened structures. In this work, the monotonic and fatigue flexural behaviors of corrosion-damaged RC beams strengthened with FRCM systems were investigated in addition to their long-term performance, i.e. after further exposure to corrosive environment following their strengthening. The work includes experimental and numerical investigations. The analytical predictions and theoretical formulations that are currently available in the design codes have been verified against the experimental results. The experimental program consisted of testing thirty (30) large-scale RC beams of 150×250×2800 mm. The beams were constructed and tested under four-point load configuration. An accelerated corrosion process was utilized to corrode the bottom steel reinforcement in the middle third of the test specimens. The test parameters included the level of corrosion damage (represented by 10, 20, and 30% mass loss in the tensile steel), the type of the strengthening system used (Polyparaphenylene benzobisoxazole (PBO-FRCM), C-FRCM, and FRP), the amount of FRCM composites (1, 2, 3, and 4 layers), the FRCM strengthening Scheme (end-anchored versus continuously wrapped layers), and the loading regime (monotonic and fatigue). The test results showed that the use of FRCM composites significantly enhanced the flexural behavior of the corroded beams. FRCM governed the failure mode of the strengthened beams rather than the level of corrosion damage of the steel bars. FRCM-strengthened beams showed an increase in their ultimate strengths that ranged between 7 and 65% of that of the virgin (neither corroded nor strengthened) beam based on the type, amount, and Scheme of the FRCM used. Exposing the repaired beams to post-repair corrosion resulted in 23% reduction in the steel mass loss. The U-wrapped scheme was more efficient than the end-anchoring scheme in delaying the delamination of the FRCM plies in the short-term repaired beams. It also mitigated the effect of the longitudinal corrosion cracks and consequently increased the post-repair strengthening effectiveness of FRCM systems. Fatigue tests showed that corrosion of steel bars dramatically decreased the fatigue life of the unstrengthened-beams. Strengthening with FRCM composites increased the fatigue life of the corrosion-damaged beams by 38 to 377% of that of the corroded-unstrengthened beams. However, FRCM strengthening did not restore the fatigue life of the virgin beams. In the numerical study carried out in this work, three-dimensional finite element (FE) models were developed to simulate the nonlinear behavior of the corroded beams strengthened with FRCM and FRP composites using the software package ATENA-3D. The results of the numerical analysis were in good agreement with those obtained experimentally in terms of failure modes, strains, load-carrying capacities, and deflections. The developed FE models were able to capture the non-linear behavior of the tested beams with good accuracy. A parametric study was then conducted to investigate the effect of concrete compressive strength and thickness of concrete cover on the strengthening effectiveness of the composite systems. It was observed that failure of RCM-strengthened beams was independent of the compressive strength of concrete or the thickness of the concrete cover and was governed only by fabric slippage within the matrix. Analytically, the design equations of ACI-549.4R-13 (ACI 2013) were assessed using the experimental data obtained from the tests. It was concluded that the theoretical formulations of CI-549.4R-13 can reasonably predict the ultimate strengths of the end-anchored strengthened beams but underestimated those of continuously-anchored beams. A scheme factor of 1.1 was then proposed to calculate the nominal strength of beams strengthened with continuously-wrapped shape of FRCM. The outcome of this work has been published (or submitted for publication) in five journal articles and five conferences, as detailed throughout the thesis.

The increasing use of Fiber Reinforced methods for strengthening existing brick masonry walls and columns, especially for the rehabilitation of historical buildings, has generated considerable research interest in understanding the failure mechanism in such systems. This dissertation is aimed to provide a basic understanding of the behavior of solid brick masonry walls unwrapped and wrapped with Fiber Reinforced Cementitious Matrix Composites. This is a new type of composite material, commonly known as FRCM, featuring a cementitious inorganic matrix (binder) instead of the more common epoxy one. The influence of the FRCM-reinforcement on the load-carrying capacity and strain distribution during compression test will be investigated using a full-field optical technique known as Digital Image Correlation. Compression test were carried on 6 clay bricks columns and on 7 clay brick walls in three different configuration, casted using bricks scaled respect the first one with a ratio 1:2, in order to determinate the effects of FRCM reinforcement. The goal of the experimental program is to understand how the behavior of brick masonry will be improved by the FRCM-wrapping. The results indicate that there is an arching action zone represented in the form of a parabola with a varying shape according to the used configuration. The area under the parabolas is considered as ineffectively confined. The effectively confined area is assumed to occur within the region where the arching action had been fully developed.

In the process of crushing concrete waste, significant amounts of fine by-products, the so called fine recycled concrete aggregates (FRCA), are generated and excluded from potential use. Limited research has thoroughly investigated the performance of concrete mixes with FRCA, very likely due to the complexity in analysing non-negligible amounts of adhered residual cement paste (RCP). Although some studies have proposed promising sustainable mix-design procedures accounting for the different microstructure when using coarse recycled concrete aggregates (CRCA), no similar approach exists for FRCA concrete. In this work, two promising procedures for mix-designing eco-efficient concrete with 100% FRCA are proposed accounting for the presence of RCP to reduce cement content in new mixtures. First, built on top of the existing procedure for CRCA mix-design, modifications to the Equivalent Volume (EV) method were introduced toconsider full replacement of fine natural sand by FRCA. Second, based on the concept of continuous Particle Packing Models (PPM), an optimized procedure was proposed to allow maximum packing density of FRCA mix linked to a given level of measured RCP content. Results verified the feasibility of producing eco-efficient concrete mixes with 100% FRCA, emphasizing the PPM mixes to report superior rheological and mechanical performance along with suitable durability-related properties. Yet, results also indicated the influence of simple or multistage crushed FRCA on the overall performance of mixes.

Concrete technology has changed greatly in the past decades. Steel fibre reinforced concrete (SFRC) is an example of the development in this field. It is obtained by adding fibres that act as a reinforcement of the cement matrix, improving the tenacity, cracking control and durability of the concrete members. In certain applications, SFRC has become an alternative material to concrete reinforced with conventional steel rebar. Despite of numerous advantages of SFRC, problems and uncertainties still exist regarding the design, the characterization and the performance of this material. Furthermore, the structural design and the properties of SFRC in real-scale elements as well as the fibre distribution are not properly clarified. All these issues need to be addressed in order to promote the safe and efficient use of the material. The objective of this doctoral thesis is to develop a systematic and innovative approach for the design optimization and characterisation of FRC precast segment. In total, 4 subjects are covered: a critical study related to the design of FRC precast segment considering the ductility requirements of the Model Code 2010; the experimental and analytical study of concrete blocks subjected to concentrated loads; the design procedure and experimental research on FRC precast segment for shafts and the anisotropy of the FRC precast segment. The first subject presents an analysis of the technical requirements demanded by the Model Code 2010 when steel fibres are the only reinforcement for concrete elements. According to this revision, an alternative approach according to the Model Code 2010 which is more compatible with the requirements of the application in tunnels is proposed. This approach may lead to the reduction of the fibre content required to guarantee a minimum ductility of the element. In order to evaluate the repercussion of the ductility criteria in terms of fibre consumption, a case study of Metro L9 of Barcelona is presented. The second subject contributes to the understanding about the behaviour of concrete blocks subjected to concentrated load. An experimental programme is performed to evaluate the influence of the height-to-length ratios in the mechanical response of the blocks. Based on the observations derived, a strut-and-tie model is adopted to assess the value of the loads Fcr and Fmax for short blocks and long blocks. A case study of Metro Line 9 in Barcelona is conducted, and the results of the study indicates that with an appropriate safety factors for the SLS and the ULS, no traditional reinforcement is required to resist the tensile stresses due to the concentrated loads applied by the jacks of the tunnel boring machine. The third subject is to verify that it is viable to replace the traditional reinforcement with steel fibres in the segmental lining ring of shaft constructed with vertical shaft machine. An analytical formulation based on MC 2010 is proposed to evaluate the minimum requirements the FRC must fulfil to carry out this replacement. Likewise, an experimental campaign was performed to characterize the mechanical behaviour of both conventional and self-compacting concrete reinforced with fibre content (Cf) between 30 and 60 kg/m3. Posteriorly, another full-scale experimental campaign of bending test on segments is performed to verify the ductile behaviour of two types of segments under failure scenario. These results are used to validate the proposed formula. The last subject focuses on the study of the anisotropy in terms of fibre distribution and local mechanical response of segments with conventional and self-compacting SFRC. For that, a large number of cores extracted from real-scale segments are tested for the fibre distribution with the inductive method and, then, for the mechanical response with the Barcelona test. A conceptual model for the fibre orientation is proposed based on the average values obtained from the tests.
La tecnología del hormigón ha avanzado notablemente en las últimas décadas. En este sentido, el hormigón reforzado con fibras (HRF) es un ejemplo del desarrollo en este campo. Este se obtiene mediante la adición de fibras que actúan como un refuerzo de la matriz de cemento, mejorando la tenacidad y el control de la figuración y, por ende, la durabilidad. En ciertas aplicaciones, HRF se ha convertido en un material alternativo para hormigón armado convencional. A pesar de las numerosas ventajas asociadas al uso del HRF, todavía existen incertidumbres en cuanto al diseño, la caracterización y el desempeño mecánico de este material. En particular, es necesario desarrollar adecuadamente el concepto y requerimiento de ductilidad de las estructuras de HRF así como integrar de forma fidedigna aspectos de orientación y de distribución de fibras en el diseño. Todas estas cuestiones deben abordarse con el fin de promover el uso seguro y eficiente del material. El objetivo de esta tesis doctoral es el desarrollo de un enfoque sistemático e innovador para el diseño y caracterización de dovelas de HRF para la ejecución de revestimiento de túneles. En total, esta tesis se cubren 4 aspectos: un estudio crítico en relación con el diseño del dovelas de HRF teniendo en cuenta los requisitos de ductilidad del Código Modelo 2010; un estudio experimental y analítico de bloques de hormigón sometidas a cargas concentradas; el pre ¿ diseño de dovelas para la ejecución de pozos verticales y el análisis de anisotropía en la distribución y orientación de fibras.En el primer tema se aborda un análisis de los requisitos técnicos exigidos por el Código Modelo de 2010 en estructuras de HRF en las que las fibras son los únicos elementos de refuerzo del hormigón. De acuerdo con esta revisión, se propone un enfoque alternativo y compatible con el MC 2010 más alineado con lo requerimiento estructurales y necesidades resistentes de las dovelas de HRF. Este enfoque conduce a la optimización del contenido de fibra necesaria para garantizar la ductilidad adecuada para estos elementos estructurales. Con el fin de evaluar la repercusión de los criterios de ductilidad en términos de consumo de fibra, se presenta un estudio de caso de Metro L9 de Barcelona.El segundo campo de investigación tratado contribuye al conocimiento en relación al comportamiento de elementos de hormigón sometidos a cargas concentradas. En este sentido, se ha llevado a cabo una campaña experimental para evaluar la influencia del ratio altura ¿ ancho en el mecanismo de rotura de los bloques ensayados. En base a las observaciones, se ha planteado un modelo de bielas y tirantes para evaluar las cargas de figuración y de rotura de los bloques. La formulación propuesta se ha empleado para evaluar dichas cargas en el caso de empuje de los gatos de las dovelas diseñadas para los túneles de la Línea 9 del Metro de Barcelona. Los resultados ponen de manifiesto que, empleando los coeficientes de seguridad adecuados, no se requiere armadura pasiva adicional para resistir los esfuerzos de tracción que se generan en la fase de empuje de los gatos, en el caso particular estudiado. Por último, en la cuarta línea de investigación se estudia en profundidad a nivel experimental la anisotropía de la distribución, cuantía y orientación de las fibras en dovelas de hormigón convencional y de hormigón autocompactante reforzadas con fibras. Para ello, se extrajeron un número elevado y representativo de testigos de las dovelas a escala real fabricadas. Se emplearon métodos no destructivos tipo inductivo para evaluar la cuantía y orientación de las fibras. Asimismo, se empleó el ensayo Barcelona (ensayo destructivo) para evaluar también ambas variables así como la resistencia a tracción residual de los hormigones. En base a los resultados se propone un modelo conceptual para estimar la orientación de las fibras en estos elementos estructurales.

In the last decades the theme of structural rehabilitation has acquired great importance and the adoption of composite materials in civil engineering applications has been a turning point in this field. The cement-based matrix of FRCM composites presents many advantages for their application to historical buildings. This dissertation presents a study of the influence of composite bonded length and width on the load response and failure mode. Two types of mortar matrix and two different steel densities were employed. The classical push pull configuration is adopted where fibers are pulled while the masonry block is restrained. Based on the experimental results and through a fracture mechanics approach, the cohesive material laws for mode II was obtained. For the completeness of the work, the characterization of each material involved in the single-lap shear test has been achieved.

Negli ultimi decenni sono state sviluppati nuovi materiali e tecnologie per il rinforzo e la riabilitazione delle strutture esistenti. I sistemi più recenti per il rinforzo esterno ed il recupero strutturale sono materiali compositi costituiti da fibre raggruppate in forma di tessuto ed impregnate ed immerse in una matrice inorganica. Quando il tessuto è composto da fibre di aramide, vetro, basalto, PBO o carbonio, questi compositi sono comunemente definiti Fabric Reinforced Cementitious Matrix (FRCM), mentre, quando il tessuto è fatto da micro-trefoli di acciaio, sono definiti Steel Reinforced Grout (SRG). In accordo con le rispettive normative, negli Stati Uniti le proprietà meccaniche dei compositi FRCM/SRG si misurano tramite una prova di tensione diretta su provini caricati utilizzando ancoraggi a forcella (clevis grip). In Europa, invece, si ricorre ad una prova di aderenza o single-lap shear su compositi applicati su un substrato cementizio o in muratura. L’obiettivo di questa tesi è confrontare i risultati ottenuti mediante i due metodi di caratterizzazione sviluppando una campagna sperimentale su due diversi tipi di compositi: un FRCM con fibra di carbonio (CFRCM) e un composito SRG. L’effetto di tre diverse lunghezze di ancoraggio è stato studiato per il sistema CFRCM. L’influenza del numero di strati di tessuto è stata analizzata sia per il sistema CFRCM che SRG considerando uno o due strati. I risultati mostrano che le differenti condizioni al contorno influenzano in modo significativo la caratterizzazione dei compositi. Per ottenere una misura rappresentativa delle proprietà meccaniche dei compositi FRCM/SRG, è richiesta una lunghezza di ancoraggio sufficiente. Questo studio contribuisce a sviluppare un database sperimentale che consenta la definizione di affidabili protocolli di caratterizzazione. Inoltre, fornisce informazioni rilevanti ai fini progettuali riguardo la lunghezza di ancoraggio adeguate e all’efficacia di applicazioni multistrato.

Uma nova classe de sistemas de controle difuso não-lineares e adaptativos denominada sistemas de controle difuso com escalonamento de ganhos indexados pela referência (FRGS), que combina as características adaptativas de controladores com escalonamento de ganhos e as características não-lineares do método de controladores difusos (fuzzy), a proposta. Além de incorporar a experiência de operadores humanos, esta abordagem permite incluir conhecimento sobre a variação nos conceitos relacionados nas funções de pertinência, diante de mudanças nas condições de operação do sistema com o qual se está interagindo. Este conhecimento permite que a superfície de controle se adapte, quando necessário, nas alterações das condições de operação, principalmente determinadas pela referência (set-point) ou outros sinais exógenos representando ou relacionados a objetivos, contexto, ambiente, distúrbio de carga etc. Ao ajustar os parâmetros do sistema difuso através de modificações introduzidas nas propriedades das funções de pertinência de acordo com diferentes condições de operação, esta abordagem pode ser aplicada tanto no projeto de controladores quanto em sistemas de suporte a decisão, ou na modelagem de sistemas dinâmicos.
A new class of adaptive, nonlinear and fuzzy systems titled Fuzzy Reference Gain-Scheduling (FRGS) systems, which combines the adaptive features of gain-scheduling along with the nonlinear characteristics of fuzzy controllers, is presented here. Besides the experience of human operators are incorporated by the parameters of control, this approach can include knowledge about variation in the concepts un-derlying the membership functions, due to changes in operational conditions. This knowledge allows the control surfaces to adapt as required by operational conditions, mainly determined by the reference (set-point) or some exogenous signals representing or related to goals, context, environment, load disturbance etc. When setting up the parameters of the fuzzy system through the modifications introduced in the membership function properties according to different operational conditions this approach can be applied to control design as well as to fuzzy decision support systems or dynamical system modelling.

Syftet med uppsatsen är att följa den syntaktiska och semantiska utvecklingen hos frasen på ett ungefär. Detta görs genom att undersöka autentisk tidningstext från två tidsperioder: 1830–1919 samt 1994–2013. Materialet är hämtat från Språkbankens korpus Korp. Den syntaktiska undersökningens syfte är att ta reda på vilken funktion i satsen på ett ungefär innehar då som nu. Detta görs genom att sätta in frasen och de satser den tillhör i satsscheman. Den semantiska analysen går ut på att utröna de betydelser på ett ungefär har haft genom åren. Enligt SAOB kan frasen ha två olika betydelser, vilka jag benämner ’uppskattningsvis’ och ’slumpvis’, och uppsatsen undersöker hur de har utvecklat sig. I den semantiska analysdelen undersöks framför allt de verb- och subjektstyper frasen står med för att se om på ett ungefär har fått en mer subjektiv innebörd. Utvecklingarna diskuteras utifrån teorier om grammatikalisering, vilket är uppsatsens teoretiska ramverk, och subjektifiering. Resultatet visar att på ett ungefär främst förekommer i satsadverbialens position A1 under båda perioderna, om än något mer under den äldre. Frasen förekommer allt oftare i objektposition N2 under den senare perioden, särskilt tillsammans med relativsatser vars huvudord är relativa adverb som hur, var och vad. Detta tolkas som att på ett ungefär alltid har kunnat vara satsmodifierande men med tiden utvecklat en alltmer ledmodifierande funktion. Betydelsen ’slumpvis’ står inte att finna någonstans i det senare materialet; på ett ungefär innehar endast betydelsen ’uppskattningsvis’ från 1990-talet och framåt. Subjekt i tredje person är alltid vanligast men subjekt i första person ökar i frekvens under de två sista årtiondena. Även en ökning av samförekomst med kognitiva verb går att utläsa i det senare materialet. På ett ungefär uppvisar flera tecken på att ha blivit grammatikaliserat. Den ledmodifierande funktionen härleds till att på ett ungefär har genomgått en reanalys, från prepositionsfras till adverb. Detta har i sin tur gett på ett ungefär funktionsmöjligheter som är reserverade för adverb, däribland att kunna modifiera exempelvis andra adverb och adjektiv. Reanalysen har gjort att på ett ungefär står djupare ned i syntaxen, något som tyder på en grammatikalisering. Därutöver tycks på ett ungefär ha genomgått en frekvensökning, utvidgning, semantisk blekning och dekategorisering. Syntaktiskt sett befinner sig på ett ungefär i ett stadie av skiktning ännu vid den senare periodens slut. Den semantiska skiktningen torde ha förkommit någon gång mellan 1919 och 1994, då ’slumpvis’ fortfarande var i bruk i slutet av den äldre perioden. Gällande subjektifiering har på ett ungefär i betydelsen ’uppskattningsvis’ alltid innehaft förmågan att talarens egen bedömning av något träder fram. Då på ett ungefär numera endast uppvisar den betydelsen ser frasen ut att ha blivit mer subjektiv.

Il mondo dei materiali compositi è in continua evoluzione ed il loro utilizzo per il rinforzo, l’adeguamento sismico e la messa in sicurezza di strutture civili è diventata una pratica comune tra gli ingegneri ed architetti. Gli FRCM (Fabric Reinforced Cementitious Matrix) rappresentano una nuova metodologia per il rinforzo strutturale e si stanno proponendo come una valida alternativa ai più affermati FRP, ogni volta che le condizioni di progetto non permettano l'uso di compositi a base di polimeri organici. Gli FRCM sono definiti dall’American Concrete Institute (ACI549) come dei sistemi costituiti dall’accoppiamento di uno o più strati di rete di fibra a elevate prestazioni e di una matrice inorganica stabilizzata impiegata con la funzione di adesivo. Gli FRCM sono generalmente costituiti da reti di fibre secche, tuttavia, si è dimostrato che il legame di interfaccia matrice-fibra non è ottimale, in quanto soltanto i filamenti esterni in contatto con la matrice sono in grado di trasferire gli sforzi, mentre i filamenti interni si sfilano a causa al basso attrito tra le fibre. Questo lavoro ha lo scopo di contribuire a migliorare ed approfondire lo stato dell’arte dei sistemi FRCM in diverse direzioni ed è suddiviso in quattro studi. In particolare la ricerca si è dedicata alla caratterizzazione di diversi sistemi FRCM, in modo da chiarire la differenza in termini di comportamento e prestazioni tra reti di fibre secche o apprettate, di analizzare gli effetti delle elevate temperature sulle proprietà meccaniche degli FRCM, di valutare l'efficacia nell’utilizzo di diverse malte (cementizie e geopolimeriche) e la compatibilità di quest’ultime con supporti in muratura. Lo scopo del primo studio è quello di analizzare come l’utilizzo di diversi tipi di coating (pre-impregnazione a base di resine epossidiche) applicati a reti bi-direzionali in fibra di carbonio vada ad influenzare il comportamento di interfaccia fibre-malta e le proprietà meccaniche dei sistemi FRCM. L'efficacia del coating è stato studiato mediante test di trazione diretta, pull-off e di adesione al supporto. La sperimentazione è stata condotta combinando diversi tipi di rete in carbonio e matrici cementizie, variando il livello di pre-impregnazione del tessuto durante la sua fabbricazione (leggera, media e completa impregnazione). Inoltre, è stato sperimentato e studiato l'utilizzo di uno strato di sabbia quarzifera applicato sulle fibre dopo l’impregnazione. Le prove sperimentali hanno dimostrato un notevole miglioramento del legame di interfaccia tra le fibre e la matrice inorganica e, quindi, un generale miglioramento delle prestazioni del sistema FRCM, anche impregnando le fibre parzialmente, a seconda del tipo di malta usata. Lo scopo del secondo studio è quello di valutare il comportamento meccanico dei sistemi FRCM sottoposti ad alte temperature. Diversi sistemi FRCM sono stati valutati, utilizzando reti bidirezionali in fibra di carbonio secche o pre-impregnate. La campagna sperimentale ha riguardato test di trazione monoassiale su provini di FRCM e test di adesione a supporti in muratura con temperature comprese tra 20 °C e 120 °C. Il terzo studio riguarda il possibile utilizzo di malte geopolimeriche come matrici per sistemi FRCM, accoppiate a diverse reti in fibra di carbonio. Lo studio ha incluso la caratterizzazione meccanica della malta, prove di trazione e di adesione a supporti in muratura. Infine il quarto studio analizza il legame di interfaccia FRCM-substrato in muratura, considerando l'utilizzo di diversi primers inorganici per migliorare l’adesione al supporto.
Composites materials are continuously evolving and their use for the repair and retrofit of civil structures has become a common practice among the engineering community. Fabric Reinforced Cementitious Matrix (FRCM) system represents a new repair methodology for structural strengthening and is becoming a viable alternative to FRP, whenever the project conditions do not allow the use of organic polymer based composites. FRCM is described by the American Concrete Institute (ACI) committee 549 like a composite material consisting of a sequence of one or more layers of cement-based matrix reinforced with dry fibers in the form of open single or multiple meshes that, when adhered to concrete or masonry structural members, forms a FRCM system. FRCMs are usually constituted by dry fabrics, however, it is proved that the bond at the matrix-fibers interface is not optimal, since only the external filaments are in contact with the matrix and able to transfer the load, while the inner filaments slip due to the low friction between the fibers. This work aims to advance the FRCM state of the art in several directions and is divided in four studies. In particular, the study is devoted to characterize several FRCM systems, to clarify the differences in performance and behavior of dry and coated fabrics, to analyze the effects of high temperatures on the FRCM mechanical properties, to evaluate the effectiveness and compatibility with masonry substrates of different mortars (cementitious and geopolymeric). The purpose of First Study is to analyze how different types and amounts of organic coatings applied to a carbon bi-directional fabric could affect the bond behavior at the fiber-mortar interface and mechanical properties of the FRCM system. The effectiveness of coating treatments applied on the fabrics surface was studied by means of direct tensile, pull-off and shear-bond double-lap tests. Experimentation was carried out on different combinations of carbon fabrics and mortars, by varying the level of pre-impregnation of the fabric during the manufacturing process. In addition, the use of a quartz sand layer applied to the fabric after impregnation was investigated. Experimental evidence showed a promising enhancement of the bond between fabric and matrix and, therefore, improved performances of the entire FRCM system even with the use of low percentages of resin, depending on the type of mortar used. The purpose of Second Study is to evaluate the FRCM mechanical behavior under high-temperature conditions. Different FRCM systems were evaluated including carbon fabrics with dry or completely impregnated fibers. The experimental campaign comprised of uniaxial tensile and double-shear bond tests performed under temperatures ranging from 20°C to 120°C. Third Study explores the use of a geopolymer mortar coupled with different carbon fabrics for FRCM applications. The study included the mechanical characterization of the mortar, tensile and double-shear bond tests of the FRCM system when applied to masonry substrates. Finally, Fourth Study analyzes the bond at the FRCM to masonry substrate interface, considering the use of different inorganic primers to improve the interface bond.

Questa tesi presenta i risultati di una campagna sperimentale incentrata sulla caratterizzazione della trazione dei basalt e glass FRCM e della caratterizzazione del legame di aderenza composito-Calcarenite. Il lavoro sperimentale è completato dalla proposta di due modelli numerici sia per prove di trazione che per quelle di aderenza. L'indagine sperimentale è stata condotta considerando l'influenza di diversi rinforzi, matrici e metodi di prova. I risultati sperimentali consentono di valutare l'effetto della malta sulle curve sforzo-deformazione, la resistenza, la duttilità e le modalità di crisi. Inoltre, la tesi fornisce un importante contributo per valutare l'influenza di diversi metodi di prova (es. clamping e clevis come riportato da diversi standard e linee guida) sulle prestazioni dei sistemi FRCM testati a trazione. Inoltre, la correlazione dell'immagine digitale è stata utilizzata per misurare le tensioni di trazione e per analizzare le modalità di crisi offrendo una caratterizzazione meccanica accurata. L'elemento di principale novità è l'adozione di un set-up per le prove di aderenza modificato e progettato per analizzare l'influenza della dimensione del composito sulla lunghezza e la resistenza del legame. Un'analisi approfondita dei risultati conferma l'efficacia di questo innovativo set-up. Infine, vengono presentati due modelli numerici che tentano di fornire un semplice strumento numerico per valutare il comportamento costitutivo dei sistemi FRCM. I modelli sono stati calibrati sulla base delle curve sperimentali sforzo-deformazione e carico-slittamento dimostrando di essere uno strumento efficace per prevedere il comportamento meccanico dei materiali compositi FRCM.
This thesis presents the results of an experimental campaign focused on the tensile characterization of basalt and glass FRCM and composite-calcarenite bond characterization. The experimental work is complemented by the proposal of two numerical models both for tensile and bond tests. The experimental investigation was carried out considering the influence of different reinforcements, matrices and testing methods. Experimental results provide for assessing the effect of mortar grade on the stress-strain curves, strength, ductility and failure modes. Moreover, the thesis provides an important contribution to assess the influence of different testing methods (i.e. clamping and clevis as reported by different standard and guidelines) on the performance of the FRCM systems tested in tension. Moreover, the Digital image correlation was used to measure the tensile strains and to analyse the failure modes offering an accurate mechanical characterization. The main element of novelty is the adoption of a modified bond test set-up designed to analyse the influence of the composite size on bond length and strength. A deep analysis of the results confirms the effectiveness of this innovative set-up. Finally, two numerical models are presented attempt at providing a simple numerical tool for capturing the constitutive behaviour of the FRCM systems. The models were calibrated on the basis of the experimental stress-strain and load-slip curves showing to be an effective tool for predicting the mechanical behaviour of the FRCM composites.

Fibre reinforced concrete (FRC) presents objectively proven advantages in terms of post-cracking strength and manufacturing procedures. As a result, FRC with structural responsibility is increasingly being used in the construction industry. However, some concerns still remain regarding design and performance given the uncertainties concerning the effect of the distribution and orientation of the fibres. In this context, further research is required to improve current tools to characterize and design FRC structures. The main topics addressed in this thesis are oriented to analyse the influence of fibres at the design stage, verify whether the constitutive models are representative and suitable to predict the response of real-scale elements and simplify FRC quality control. At the design stage, the influence of size-effect on the bending tests used to determine the constitutive model has been analysed. Additionally, a model to estimate the residual strength of FRC based on the orientation of the fibres is proposed. Flexural tests on real-scale slabs reinforced with rebars and fibres have been analysed and compared to numerical simulations using the constitutive model of the Model Code 2010 (MC2010). Finally, a correlation based on the Barcelona test (BCN) is proposed as an alternative to the three-point bending test in quality control. The first part of the study focuses on the pre-design stage of FRC. Standard and non-standard specimens were tested under a three-point bending test (3PBT) configuration to calculate the parameters defining the MC2010 constitutive model for FRC. The results revealed that the size-effect in small non-standard specimens can be mitigated if, instead of the CMOD, the rotation of the sample is used as the reference parameter to determine the residual strengths associated to the constitutive law. Subsequently, a model to estimate the post-cracking strength of FRC is presented. Given a degree of isotropy and a content of fibres, the model assigns a position and an orientation to each fibre. Assuming that only fibres contribute to the tensile strength after cracking, the pull-out load of all the fibres combined with the sectional equilibrium can be used to determine the post-cracking strength of FRC. The estimations of the post-cracking strength curves are able to reflect the influence of the specimen dimension as well as the content and the orientation of the fibres. After the pre-design stage, real-scale slabs with different combinations of rebars and fibres were tested to analyse the influence of fibres on the flexural behaviour, cracking patterns and ductility. The experimental results were used to verify the predicted flexural response of the slabs simulated by means of sectional analyses and finite element methods based on the constitutive law of the MC2010. The simulations revealed a general overestimation of the flexural performance when compared to the experimental results. The last part of the study aims to present an alternative method to optimize and streamline quality control of FRC based on a correlation between the 3PBT and the BCN. For this purpose, an experimental programme on mixes with different rheologies, compressive strengths and types and contents of fibres was conducted. The procedure to determine such a correlation is described while showing the importance of considering confidence intervals in the presence of results with high variability as in FRC.
El hormigón reforzado con fibras (HRF) presenta ventajas objetivamente probadas en términos de resistencia residual y procesos de producción. En consecuencia, el HRF con responsabilidad estructural ha experimentado una creciente demanda en el sector de la construcción. No obstante, su uso aún suscita ciertas preocupaciones debidas esencialmente a la influencia de la distribución y la orientación de las fibras en la capacidad resistente. En este sentido, se hace necesario continuar investigando con el objeto de mejorar los métodos actuales de caracterización y diseño del HRF. Los principales aspectos que se abordan en esta tesis están orientados a analizar la influencia de las fibras en la etapa de diseño, verificar la capacidad de los modelos constitutivos para predecir la respuesta estructural de elementos a escala real y simplificar el control de calidad del HRF. En la etapa de diseño, se ha estudiado la influencia del efecto escala en los ensayos de flexión destinados a obtener las ecuaciones constitutivas de HRF. Asimismo, se ha propuesto un modelo para estimar la resistencia residual del HRF basado en la orientación de las fibras. Por otro lado, se ha analizado el comportamiento a flexión de losas reforzadas con fibras y barras de acero, tras lo que se ha comparado los resultados experimentales de dichos ensayos con simulaciones numéricas basadas en las ecuaciones constitutivas descritas en el Model Code 2010 (MC2010). Finalmente, se propone una correlación basada en el ensayo Barcelona (BCN) como alternativa al ensayo a flexión a tres puntos (3PBT) en la fase de control de calidad. La primera parte del estudio se enfoca en la etapa de pre-diseño del HRF. Para ello, se han ensayado probetas prismáticas de distintos tamaños bajo una configuración de ensayo 3PBT para calcular los parámetros que definen la ecuación constitutiva del HRF según los criterios del MC2010. Los resultados muestran que el efecto escala puede verse reducido utilizando el giro, en lugar del CMOD, como parámetro de referencia para calcular las resistencias residuales asociadas a la ecuación constitutiva. Posteriormente, se propone un modelo para estimar la resistencia residual del HRF. A partir de la isotropía y el contenido de fibras, se asigna a cada fibra una posición y una orientación determinada. Asimismo, el modelo asume que en estado fisurado únicamente las fibras contribuyen a la resistencia a tracción. De este modo, la contribución al arrancamiento de todas las fibras en combinación con el equilibrio seccional puede utilizarse para calcular la resistencia residual del HRF. De acuerdo con los resultados obtenidos, la resistencia residual calculada mediante el modelo es capaz de reflejar la influencia del tamaño de probeta, el contenido de fibras y su orientación. Tras el estudio de la fase de pre-diseño, se ensayaron losas a escala real con diferentes combinaciones de HA y HRF con el objeto de analizar la influencia de las fibras en la respuesta a flexión, la aparición de fisuras y la ductilidad. Los resultados experimentales se utilizaron para verificar la idoneidad del modelo constitutivo del MC2010 cuando se utiliza para simular el comportamiento a flexión mediante análisis seccional y tridimensional mediante elementos finitos. Este estudio muestra que los resultados de las simulaciones presentan una sobreestimación generalizada de la respuesta a flexión de las losas en comparación con los resultados experimentales.

The rehabilitation of existing masonry elements through jacketing of columns using composite materials is becoming a remarkable technique in several applications that aim to increase the strength of existing masonry building. An experimental campaign was conducted with Steel- and -Basalt Fiber Reinforced Cementitious Matrix (FRCM) systems, in order to test new products that might increase the advantages in terms of good adhesion to masonry substrate, breathability of the system, efficiency in aggressive environments, ease of installation and reversibility, which are essential for the preservation of historical buildings. The mean objective of this experimental study was to investigate the state of the improvement of square masonry columns, built in alternate stretcher and header bond configuration using as material confinement Steel- and-Basalt FRCM system, subjected to axial compression. Moreover, the effectiveness and influence of the confinement in terms of load-bearing capacity and strain distribution with respect to unconfined prisms was carried out. An optical technique, known as Digital Image Correlation (DIC), was employed to understand the interaction between the unit masonry components.

In the last years, due to many severe seismic events, it becomes more and more important to understand the structural performance of stone masonry structures subjected to seismic actions and structural reinforce became an important task in civil engineering. The developments of innovative techniques for structural retrofitting represent a great change in order to reduce the seismic vulnerability of stone masonry buildings. Beside the traditional reinforce techniques, new reinforce born such as Fiber Reinforced Polymer (FRP) and Fiber Reinforced Cementitious Matrix (FRCM) The aim of this thesis is to study the shear strength of masonry panels, subjected to in-plane actions, reinforced with FRCM

In Canada, the extent of deterioration has prompted many authorities, including the federal and provincial governments, to investigate the potential use of fibre-reinforced polymer (FRP) products to extend the life of their existing structures. Fibre optic sensors (FOS) are serious candidates for the long-term monitoring of both existing and new structures throughout their working life. Research up to date demonstrated the potential of both FRP and FOS systems in the civil engineering field. The FRP systems used as an external reinforcement proved to be very efficient in increasing the strength of concrete structures. However, few studies focused on the long-term durability of these materials when used as external reinforcement of RC beams. As a result, there is a concern regarding the fatigue resistance of these materials when they are exposed to harsh environmental conditions. Previous studies showed that the FOS systems were successfully integrated in FRP products and tested in various loading conditions. A few studies touch upon the fatigue resistance of FOS, and no study has been reported on their durability when exposed to aggressive environments. It is important to understand the behaviour of FOS when they are submitted to these conditions before implementing them extensively in long-term health monitoring projects. This extensive experimental project was undertaken in order to assess the durability of FOS systems installed on the FRP used as external reinforcement for reinforced concrete beams. Knowing that the FOS installed on a support structure was submitted to various loading and water exposure conditions, the durability of both the FOS and RC beams strengthened with carbon-fibre-reinforced polymers was assessed. The originality of this study consists in the fact that, to the author's knowledge, it is the only experimental program on the durability of FOS installed on a structural element submitted to various fatigue and post-fatigue loading conditions. In addition, it combines the effects of fatigue loading with water exposure conditions. The maximum strain values as well as the numbers of fatigue cycles to which the FOS were tested are larger than in any other previous study. Moreover, the RC beams strengthened with FRP tested in the same conditions with the FOS, were submitted to environmental fatigue, that is water exposures combined with fatigue loading. Finally, the impact resonance method (IRM), a non-destructive testing technique, was for the first time employed to monitor fatigue damage for this type of specimens."--Résumé abrégé par UMI.

Il presente lavoro è volto allo studio di soluzioni di rinforzo strutturale di edifici storici in muratura mediante materiali compositi innovativi a matrice inorganica FRCM (Fiber Reinforced Cementitious Matrix). E' stato effettuato un confronto tra due sistemi di rinforzo con compositi SRG (Steel Reinforced Grout) in fibre d'acciaio ad altissima resistenza, nell'ottica di un progetto di miglioramento sismico del teatro Pavarotti di Modena, in particolare della parete di fondo retrostante il palcoscenico. Ipotizzati alcuni meccanismi di collaso della parete, la vulnerabilità sismica della stessa, nei confronti di ciascun meccanismo, è stata valutata attraverso l'analisi cinematica lineare. Successivamente per ogni meccanismo è stato studiato un sistema di rinforzo SRG al fine di incrementare la capacità sismica della parete e il moltiplicatore di collasso.

Frc, a major gene on chromosome 8, conditions fructan levels in onions (Allium cepa L). In order to assist genetic dissection of this locus, this study aimed to determine the factors influencing varying fructan levels in high- and low-fructan genotypes. Mapping families were developed and analysed to study the genetic architecture for the fructan trait, and to check the association of the identified variables with the Frc locus. To facilitate reliable and practicable sugar assays in onions, a newly-adapted high-throughput microplate enzymatic assay was validated in this study. The reliability of using leaf sugars as a representative of bulb sugars in a mapping population was studied. Microplate enzymatic sugar assays were carried out on a segregating onion cross to validate the use of maltases in sugar analysis, and the results obtained were validated against HPLC-PAD. Sucrose measured in microplates employing maltases as the hydrolytic enzyme was in agreement with HPLC-PAD results. Maltase enzymes specifically hydrolysed sucrose in onions, providing an alternate tool in place of expensive sugar assay kits. Use of the microplate-enzymatic assay provided a rapid, cheap and practicable method for sugar analysis in onion. Differences in carbohydrate content, sucrose metabolising enzyme activities and their expression levels were monitored in developing leaf blades and leaf bases of four high- and four low-fructan genotypes. The variation in fructan accumulation between high- and low-fructan genotypes was due to the variation in sucrose metabolism. SPS expression and activity did not vary between high- and low-fructan genotypes. Acid invertase and 1-SST showed significant variation in their activities between the two fructan groups. Post-transcriptional and translational regulation of AI and 1-SST respectively, are suggested. Mapping populations analysed for non-structural carbohydrates showed very wide segregation for fructan (80 to 600 g kg⁻¹) and other NSC content, and were well-suited for detailed genetic and physiological analysis. Single marker analysis was carried out to study the association between the combined enzyme activity (CEA; acid invertase + 1-SST) and the Frc markers. Significant association between CEA and Frc markers has suggested genes regulating acid invertases or 1-SST or both underlie Frc. Leaf blade NSC did not correlate with bulb sugars and thus cannot be used as a phenotypic marker for early selection of bulb NSC traits.

This thesis investigates the repair of impact-damaged prestressed concrete bridge girders with strand splices and fabric-reinforced cementitious matrix systems, specifically for repair of structural damage to the underside of an overpass bridge girder due to an overheight vehicle collision. Collision damage to bridges can range from minor to catastrophic, potentially requiring repair or replacement of a bridge girder. This thesis investigates the performance of two different types of repair methods for flexural applications: strand splice repair, which is a traditional repair method that is often utilized, and fabric-reinforced cementitious matrix repair, which is a relatively new repair method. The overarching goal of this project was to provide guidance for assessment and potential repair of impact-damaged girders. Prestressed concrete girders were tested to failure in flexure in this research. After a control test to establish a baseline for comparison, five tests were performed involving damaging a girder, repairing it using one of the repair methods, and testing it to failure. These tests showed that both strand splice repairs and fabric-reinforced cementitious matrix repairs can adequately restore the strength of an impact-damaged girder when up to 10% of the prestressing strands are severed. Combined repairs can also be a viable option if more than 10% of the prestressing strands are severed, though as the damage gets more severe, girder replacement becomes a more attractive option.
Master of Science

Fiber reinforced cementitious matrix (FRCM) composites represent a newly-developed promising alternative to traditional materials for strengthening and retrofitting reinforced concrete and masonry structures. FRCM composites present several advantages with respect to fiber reinforced polymers (FRP) composites. However, while FRP composites have been extensively studied in the last decades and several design guidelines and analytical formulations are available, FRCM composites are still in their infancy and very few data are present in the literature. Thus, another issue that should be solved regards the stated need for the anchorage systems to improve FRP and FRCM strength in situations where debonding or lack of development length is a problem. In this study, the effectiveness of the anchorage system and the interaction with an externally bonded FRCM were studied on both concrete beams and masonry columns. The columns and beams were tested until failure condition in the Laboratory of Structural and Geotechnical Engineering (DICAM – LISG) of the University of Bologna, via del Lazzaretto 15/5, Bologna. Test parameters considered for this study are: density of steel fibers, type of anchorages and bending inclination of the fiber exerted as anchorage, respectively 45° for concrete beam and 90° for masonry column. Test results demonstrate that the introduction of additional anchorages improves the effectiveness of the FRCM composites in terms of resistance and loading capacity.

Thesis (Ph. D.)--Georgia State University, 2006.
Title from title screen. Julian Diaz III, committee chair; Alan J. Ziobrowski, Paul Gallimore, J. Andrew Hansz (University of Texas at Arlington), committee members. Electronic text (172 p. : ill.) : digital, PDF file. Description based on contents viewed July 23, 2007. Includes bibliographical references (p. 166-171).

Si analizza il comportamento e la risposta di elementi sottoposti a diversi tipi di sollecitazione. Lo scopo ultimo è quello di valutare l’applicabilità di un modello che permetta di ricavare il comportamento di creep a trazione nei calcestruzzi fibrorinforzati, partendo dai risultati delle prove di creep a compressione e creep a flessione.

Approved for public release, distribution unlimited
MBA Professional Report
In an effort to foster process improvement and ensure cost-wise support of the ongoing military operations throughout the world, Fleet Readiness Center Southwest (FRC SW) created its Continuous Process Improvement (CPI) as a vehicle to establish cost-wise readiness throughout its organization. The goal of this MBA project is to determine a reasonable range of production at Fleet Readiness Center Southwest (FRC SW) while attempting to maximize flexibility to support the fleet. The success of our project depended on to conducting capacity measurement analysis to support our findings and recommendations in assisting FRC SW. We used several modeling tools to assess capacity, which assisted in locating some of the constraints on the C2 production line at FRC SW. We found that the scope of the C2 production line requires further capacity analysis using tools beyond our project. We concluded our project with a recommendation for future research using modeling and simulation.

"Submitted in partial fulfillment of the requirements for the degree of Master of Business Administration from the Naval Postgraduate School, June 2009."
Advisor(s): Heath, Susan ; Euske, Kenneth. "June 2009." "MBA professional report"--Cover. Description based on title screen as viewed on July 14, 2009. DTIC Identifiers: CPI (Continuous Process Improvement), C2 Greyhound, capacity analysis, process flow. Author(s) subject terms: C2 Greyhound; Capacity Analysis; AirSpeed Toolset; Process Flow; Precedence Diagram; Work Breakdown Structure (WBS); PMI3 Includes bibliographical references (p. 43-44). Also available in print.

Why Do Borrowers Choose Arms Over FRMS? : A Behavioral Investigation in the U.S. and Japan by Masaki Mori In the U.S., a considerable number of borrowers still choose adjustable rate mortgages (ARMs) over fixed rate mortgages (FRMs), even with historically low interest rates. During 2004-2005, when interest rates remained at 30-year lows, ARMs accounted for approximately one-third of all mortgage originations. Kahneman and Tversky's Prospect Theory’s reflection hypothesis suggested that people tend to be more risk-averse in positive decision situations, while they tend to be more risk-seeking when making negative choices. The first purpose of this study is to examine descriptive reasons for the popularity of ARMs in the U.S. People of different cultures often evaluate uncertain events in different ways. Hofstede developed a cultural dimension, uncertainty avoidance (UA), where UA is defined as the extent to which people feel threatened by uncertain situations. The second purpose of this study is to test the role of UA on the choice of mortgage products using data from two cultures (U.S. and Japan), potentially differing in attitude toward uncertain situations. Controlled experiments were conducted using 92 U.S. participants and 49 Japanese participants. Results of analysis supported Prospect Theory’s reflection hypothesis, suggesting that risk-averse people tend to become more risk-seeking when choosing a mortgage type, leaning more toward ARMs when people frame the mortgage choice problem as part of a loss situation. The results of the intercultural comparison portion of the study supported the research hypothesis that UA works as a moderating variable for Prospect Theory’s reflection hypothesis, suggesting that risk-averse people with lower UA scores more dramatically change from a risk-averse preference for a fixed-rate bond to a more risk-seeking preference for an adjustable-rate mortgage, than risk-averse people with higher UA scores do. Overall, results of this study suggested that borrowers behave differently depending on their propensity for current consumption, the level of UA, and how they frame the mortgage choice decision. This study contributes to existing mortgage choice literature by incorporating psychological and cultural traits to examine borrowers’ attitudes towards interest rate risk with regard to residential mortgages. The findings are of great importance globally for governments and lenders in creating and introducing new mortgage products in countries with diverse cultures.

Unreinforced masonry (URM) walls are often used as load-bearing or infill walls in buildings in many countries. Such walls are also commonly found in existing and heritage buildings in Canada. URM walls are strong structural elements when subjected to axial loading, but are very vulnerable under out-of-plane loads. This type of loading may come from different sources , including seismic or blast events. When subjected to blast, wall elements experience large pressures on one of their faces due to the high pressure produced in the air when an explosion takes place. This wave of compressed air travels in a very short time and hits the wall causing immense stresses, which result in large shear and bending demands that may lead to wall failure, and the projection of debris at high velocities that can injure building occupants. This failure process is highly brittle due to the very low out-of-plane strength that characterize such walls. In the past years, many investigations have been carried out to enhance the structural behaviour of unreinforced masonry walls under out-of-plane loading. Different strengthening methods have been studied, which include the use of polyurea coatings, the application of advanced fiber-reinforced polymer (FRP) composites or the use of concrete overlays in combination with high performance reinforcement. Fabric-reinforced cementitious matrix (FRCM) is a new composite material that overcomes some of the drawbacks of FRP. This composite material consists of applying coatings which consist of one or more layers of cement-based mortar reinforced with a corresponding open mesh of dry fibers (fabric). This material has been studied as a strengthening technique to improve in-plane and out-of-plane capacity of existing URM walls as well as other structural elements, mostly under seismic actions. This thesis presents an experimental and analytical study which investigates the effectiveness of using FRCM composites to improve the out-of-plane resistance of URM walls when subjected to blast loading. As part of the experimental program, three large-scale URM masonry walls were constructed and strengthened with 1,2 and 3 layers of FRCM using unidirectional carbon fabrics. In all cases the specimens were built as load-bearing concrete masonry (CMU) walls. To increase shear resistance, two of the walls were also grouted with a flowable self-compacting concrete (SCC) mortar. Blast tests were conducted using the University of Ottawa Shock Tube and the results are compared with control walls tested in previous research at the University of Ottawa. The experimental results show that the FRCM retrofit significantly improved the blast performance of the URM load-bearing walls, allowing for increased blast capacity and improved control of displacements. The performance of the retrofit was found to be dependent on the number of retrofit layers. As part of the analytical research, Single Degree of Freedom (SDOF) analysis was carried out to predict the blast behaviour of the strengthened walls. This was done by computing wall flexural strength using plane sectional analysis and developing idealized resistance curves for use in the SDOF analysis. In general, the analysis procedure is found to produce reasonably accurate results for both the resistance functions and wall mid-height displacements under blast loading.

Introdução: No Brasil há carência de instrumentos validados para a análise do curso da Demência Frontotemporal (DFT). Dessa forma, torna-se relevante a validação da Escala de Estadiamento e Progressão da Demência Frontotemporal (FTD-FRS). Em nosso meio, as escalas de estadiamento das demências, como a Clinical Dementia Rating (CDR), foram elaboradas para graduar a doença de Alzheimer (DA) e não incluem os sintomas específicos da DFT. Objetivos: 1. Realizar a tradução, adaptação transcultural e validação da FTD-FRS para o contexto brasileiro. 2. Avaliar a capacidade da FTD-FRS detectar alterações em pacientes com DFTvc, afasia progressiva primária (APP) e DA após 12 meses da avaliação inicial, em comparação com a escala CDR para DLFT, e com a CDR original. Métodos: Participaram do estudo 101 indivíduos com idade igual ou superior a 40 anos, com escolaridade formal acima de dois anos, sendo 31 pacientes com diagnóstico de DFT variante comportamental (DFTvc), doze pacientes com afasia progressiva primária (APP), 28 pacientes com doença de Alzheimer (DA), oito com comprometimento cognitivo leve (CCL) e 22 controles normais (CN). Foram entrevistados os familiares ou cuidadores que tinham contato frequente com o paciente. Os pacientes com DA, e com os subtipos de DFT foram pareados quanto à gravidade da doença, segundo a CDR. Resultados: Foi realizado o processo de adaptação transcultural da FTD-FRS. Consistiu em: tradução, retrotradução (realizadas por tradutores independentes), discussão com especialistas sobre a versão em português e equivalência com a versão original, e desenvolvimento da versão final. A consistência interna da FTD-FRS, estimada pelo alfa de Cronbach foi 0,975, e o coeficiente de correlação intra-classe, para a estabilidade no teste e reteste em seis meses foi de 0,977. A análise fatorial revelou a existência de quatro fatores que se correlacionaram significativamente com os domínios da CDR-DLFT. Os pacientes com DFTvc apresentaram progressão mais rápida em 12 meses do que os demais subtipos de demência na FTD-FRS, na CDR-DLFT e na CDR-original. Considerações finais: A FTD-FRS tem propriedades psicométricas adequadas para seu uso clínico no Brasil. Este instrumento pode auxiliar na caracterização de sintomas clínicos relevantes para o diagnóstico e estadiamento da DFT. Também pode documentar os resultados relacionados à intervenção terapêutica. Este estudo fornece aos clínicos e pesquisadores um instrumento válido para estadiamento e acompanhamentode de pacientes diagnosticados com DFT
Introduction: In Brazil there is a shortage of validated instruments for the analysis of the course of Frontotemporal Dementia (FTD). Thus, the validation of the Frontotemporal Dementia Staging and Progression Scale (FTD-FRS) becomes relevant. In our setting, dementia staging scales, such as the Clinical Dementia Rating (CDR), were designed to stage Alzheimer\'s disease (AD) and did not include the specific symptoms of FTD. Objectives: 1. To perform the translation, cross-cultural adaptation and validation of the FTD-FRS for the Brazilian context. 2. Evaluate the ability of the FTD-FRS to detect changes in patients with bvFTD, primary progressive aphasia (PPA) and AD after 12 months of the initial evaluation, compared to the CDR scale for FTLD, and with the original CDR. Methods: A total of 101 individuals aged 40 years and older, with formal schooling above two years of age, were included in the study. Twenty-one patients were diagnosed with bvFTD, twelve patients with PPA, 28 AD, eight with mild cognitive impairment (MCI) and 22 normal controls (NC). Family members or caregivers who had frequent contact with the patient were interviewed. Patients with AD and with FTD subtypes were matched for disease severity, according to CDR. Results: The process of cross-cultural adaptation of the FTD-FRS was carried out. It consisted of: translation, back-translation (carried out by independent translators), discussion with experts about the Portuguese version and equivalence with the original version, and development of the final version. The internal consistency of the FTD-FRS, estimated by the Cronbach\'s alpha was 0.975, and the intra-class correlation coefficient for the test and retest stability at six months was 0.977. Factor analysis revealed the existence of four factors that correlated significantly with the CDR-DLFT domains. Patients with bvFTD showed faster progression at 12 months than the other dementia subtypes in the FTD-FRS, CDR-DLFT and CDR-original version scales. Final considerations: FTD-FRS has psychometric properties suitable for clinical use in Brazil. This instrument may aid in the characterization of clinical symptoms relevant to the diagnosis and staging of FTD. It can also document the results related to therapeutic interventions. This study provides clinicians and researchers with a valid instrument for staging and follow-up of patients diagnosed with FTD