Steel frame construction with unreinforced masonry infill walls is a common system found in high-rise structures built in the late nineteenth and early twentieth centuries. Recorded performance of this dual system during seismic events shows that the structures are able to resist a high level of lateral loads without collapse, primarily because a majority of damage is confined to the infill walls instead of the gravity carrying frame. To better understand expected performance of this structural system in different seismic risk regions, a prototypical building was analyzed using modal and nonlinear static procedures based on currently accepted evaluation guidelines. Nonlinear results from the computer model were compared with calculated target displacements for seventeen cities likely to have steel frame construction with unreinforced masonry infill in order to determine expected damage levels at varying levels of seismic risk. It was concluded that the structural system studied could experience damage in all seismic risk regions, including post-yield damage of the structure, although in low risk regions that damage is confined entirely to the infill walls. Practicing structural engineers should be aware that in all seismic risk zones existing steel frame buildings with unreinforced masonry infill, while able to resist a high magnitude of displacement without complete structural failure, will require additional lateral support under currently accepted rehabilitation guidelines.

A large amount of low-rise unreinforced masonry structures (URM) can be foundin Groningen, the Netherlands. More and more induced earthquakes with shortduration have been detected in this region due to gas exploitation. Local unreinforcedmasonry (URM) buildings were initially not designed for withstanding seismicactions, so that unexpected damage may occur due to their vulnerability, raising insecurityamong residents. Existing low-rise masonry buildings in Groningen can bedivided into different categories based on their characteristics. Two types of residentialmasonry buildings that fulfil the prerequisites for performing non-linear seismicassessment are chosen to be studied in this thesis project, including the terracedhouse and the detached house.The seismic assessment of structures requires the use of both a discretization methodand a seismic assessment method. The discretization method is used to translate themechanical model into a finite element model used for the numerical analysis. Severalmethods have previously shown to be applicable for seismic assessment, but thiswork investigates the implications of using a continuum model (CM) and an equivalentframe model (EFM) approach to discretization in the general-purpose finiteelement package described in DIANA-FEA-BV (2017). The continuum model approachadopted was in a previous work by Schreppers et al. (2017) validated againstexperimental results and is as such deemed representative of the physical behaviourof the mechanical models investigated. An equivalent frame model approach to beused with DIANA is proposed in the work by Nobel (2017). The continuum modelapproach uses continuum elements with a constitutive model developed for the seismicassessment of masonry structures. This constitutive model captures both shearand flexural failure mechanisms. The equivalent frame model approach uses a combinationof numerically integrated beam elements and nodal interfaces, each witha distinct constitutive model, thus decoupling the description of the flexural andshear behaviour. This approach aims to capture the macro-behaviour at the structurallevel. The applicability of the proposed equivalent frame model approach isevaluated by how well it replicates the validated continuum model approach results.The two discretization methods described are evaluated using two types of seismicassessment methods. The first seismic assessment method used consists of first performinga quasi-static non-linear pushover analysis (NLPO) on the model. Thisresults in the pushover curve, which describes the global behaviour of the modelunder an equivalent lateral load based on the fundamental mode shape of the structure.The pushover curve is then used with the N2-method described in EN1998-1iii(2004) to assess at which peak ground acceleration (PGA) that the model reachesthe near-collapse (NC) limit state. The second seismic assessment method consistsof performing dynamic non-linear time-history analyses (NLTH). This method usesrecorded accelerograms to impose the inertial forces. The PGA for the accelerogramwhere the near-collapse limit state is reached is compared to the PGA fromthe use of the N2-method. The applicability of the pushover analysis in conjunctionwith the N2-method is evaluated by how well it replicates the PGA found from thetime-history analyses and by how well it replicates local failure mechanisms.Therefore, the main objectives of this project can be described by the following twoquestions:i. To what extent can the equivalent frame method be applicable as a properdiscretization method for pushover analyses and time-history analyses oflow-rise unreinforced masonry residential buildings in the Groningen region?ii. To what extent can the non-linear pushover method be adopted toassess the seismic behaviour of low-rise unreinforced masonry residentialbuildings in the Groningen region?The applicability of the equivalent frame model showed to vary. For describing localfailure mechanisms its applicability is poor. Further work on connecting the edgepiers to transverse walls is needed. For seismic assessment using the N2-method theapplicability of the equivalent frame model approach is sensible. The conservativedisplacement capacity counteracts the fact that it is worse at describing local unloading,which produced a larger initial equivalent stiffness of the bi-linear curvesin comparison to the continuum model. For seismic assessment using the timehistorysignals, its applicability is possible. While it could show different behaviourin terms of displacement and damping forces, it still showed a similar PGA at thenear-collapse limit state for the cases at hand.The seismic assessment of the terraced and detached houses by the N2-method issimilar to the seismic prediction by applying time-history analyses. However, thereare still some variations in the initial stiffness, force capacity and displacement capacitybetween these two assessment methods due to the assumptions and limitationsin this study. Overall, considering the pros and cons of the quasi-static pushovermethod, it is deemed applicable during the seismic assessment of the unreinforcedmasonry structures in the Groningen area.

Idag är intresset för högpresterande betong (HPB) växande runt om världen då fördelarna är många, eftersom slankare, tätare, starkare och lättare konstruktioner kan tillverkas.   Detta examensarbete handlar om materialförsök och modellering för en typ av HPB som ska användas i husbyggnation. Arbetet inleddes med materialförsök i färskt tillstånd, där god gjutbarhet och konsistens eftersträvades. Utgångspunkten var från ett grundrecept med två olika ballastsorter (slaggballast med flygaska och krossballast från asfaltindustrin med silikastoft), vilka namngavs till pilotförsök 1 och pilotförsök 2. Vidare valdes pilotförsök 1 att provas i hårdnat tillstånd då det visades att det var mer ekonomiskt lönsam eftersom ballasten inte behövde siktas, lägre vct tillhandhölls och att flygaskan som användes i pilotförsök 1 är billigare än silikastoft som användes i pilotförsök 2. Resultaten efter 28 dygn för de materialförsök som utfördes i hårdnat tillstånd var: Tryckhållfasthet; 141,9 MPa Draghållfasthet; 7,0 MPa Böjdraghållfasthet; 10,0 MPa Elasticitetsmodul; 46,4 GPa Krympning efter 56 dygn; 0,5 ‰ Samtliga försök utfördes enligt svenska standarder (SS).   Dessutom vidareutvecklas och förbättrades ett redan arkitektoniskt gestaltat Attefallshus ur ett konstruktions- och hållbarhets perspektiv, där fokus låg på transport- och produktionsförutsättningar. Det resulterade i att horisontella avstyvningar tillades i väggelementen för att öka styvheten och minska risken för brott under transport och produktion. Huset är tänkt att produceras med prefabriceringsteknik. Avslutningsvis modellerades ett oarmerat väggelement i FE-programmet Abaqus under linjärt elastiskt tillstånd. Vid modelleringen användes de materialparametrar som erhölls från materialförsöken.  Det resulterade i att deformationer, spänningar samt knäcknings- och bucklingsanalys kunde redas ut. Väggelementen i huset klarar normenliga laster enligt modelleringen. / Nowadays the interest for high-performance concrete (HPC) is growing around the world as the benefits are many, for example slender, denser, stronger and lighter structures can be manufactured.   This thesis is about material and design experiments for a type of HPC to be used in building construction. The work began with materials experiments in the fresh state, where good workability and consistency were tried to be obtained. The starting point was from a basic recipe with two different aggregate types (slag aggregates with fly ash and crushed aggregates from the asphalt industry with silica fume), which were named as the pilot test 1 and the pilot test 2. Furthermore pilot test 1 was elected to be tested in hardened state as it turned out to be more economically profitable, had a lower vct, and that the flyash was cheaper than the silica fume used in the pilot test 2. The results after 28 days when the materials experiments were carried out in the hardened state were: Compressive strength; 141,9 MPa Tensile strength; 7,0 MPa Flexural strength; 10,0 MPa Modulus of elasticity; 46,4 GPa Shrinkage after 56 days; 0,5 ‰ All experiments were performed according to Swedish standards SS.   Moreover, an existing architecturally portrayed Attefallshus was further developed and improved from a design and a strength perspective that mainly focused on transport and production. It resulted in the horizontal stiffeners to be installed in the wall elements to increase rigidity and reduce the risk of breakage during shipment and production. The house is intended to be built with prefabrication technology. Finally the unreinforced wall elements were modeled in the FE program ABAQUS under linear elastic condition. During modeling the material parameters obtained from material tests were used in the model. Consequently, strain, stress and buckling analysis could be made. The wall sections in the house met the norm loads according to the model.

Denna studie presenterar en jämförelse mellan KL-trä och olika former av betong (armerad/oarmerad och platsgjuten/prefabricerad) som väggmaterial i byggnadskonstruktioner. Syftet är att analysera deras respektive miljöpåverkan och kostnadseffektivitet. Trots en initialt högre kostnad per kvadratmeter, har KL-trä en betydligt lägre miljöpåverkan, vilket medför en nettovinst för miljön jämfört med betongväggarna. Bland betongalternativen uppvisar oarmerad platsgjuten betong en balans mellan lägre kostnader och mindre CO2-utsläpp. Studien lyfter fram behovet av standardiserade, pålitliga data om miljöpåverkan inom byggindustrin för att stödja hållbara beslut. Den pekar på potentialen i ytterligare forskning som syftar till att reducera både kostnader och miljöpåverkan för KL-trä, för att främja dess bredare användning i byggsektorn. Studien erbjuder därmed viktiga insikter för att driva en mer hållbar och ekonomiskt lönsam byggindustri. / This study presents a comparison between CLT and various kinds of concrete (reinforced/unreinforced and cast in place versus prefabricated) as wall material in building constructions. The purpose is to analyse their respective environmental impact and cost efficiency. Despite an initially higher cost per square meter CLT has a considerably lower environmental impact, which entails a net profit for the environment compared to the concrete walls. Among the concrete options, walls without rebar and cast in place exhibits a balance between lower costs and CO2eemissions. This study highlights the need of standardized, trustworthy data of the environmental impact in the construction industry to support sustainable decisions. It points to the potential in further research which intends to reduce both cost and environmental impact for CLT, to further promote its use in the construction industry. The study thus offers important insights for driving a more sustainable and economically profitable construction industry.

A large amount of low-rise unreinforced masonry structures (URM) can be found in Groningen, the Netherlands. More and more induced earthquakes with short duration have been detected in this region due to gas exploitation. Local unreinforced masonry (URM) buildings were initially not designed for withstanding seismic actions, so that unexpected damage may occur due to their vulnerability, raising insecurity among residents. Existing low-rise masonry buildings in Groningen can be divided into different categories based on their characteristics. Two types of residential masonry buildings that fulfil the prerequisites for performing non-linear seismic assessment are chosen to be studied in this thesis project, including the terraced house and the detached house. The seismic assessment of structures requires the use of both a discretization method and a seismic assessment method. The discretization method is used to translate the mechanical model into a finite element model used for the numerical analysis. Several methods have previously shown to be applicable for seismic assessment, but this work investigates the implications of using a continuum model (CM) and an equivalent frame model (EFM) approach to discretization in the general-purpose finite element package described in n DIANA-FEA-BV (2017). The continuum model approach adopted was in a previous work by Schreppers et al. (2017) validated against experimental results and is as such deemed representative of the physical behaviour of the mechanical models investigated. An equivalent frame model approach to be used with DIANA is proposed in the work by Nobel (2017). The continuum model approach uses continuum elements with a constitutive model developed for the seismic assessment of masonry structures. This constitutive model captures both shear and flexural failure mechanisms. The equivalent frame model approach uses a combination of numerically integrated beam elements and nodal interfaces, each with a distinct constitutive model, thus decoupling the description of the flexural and shear behaviour. This approach aims to capture the macro-behaviour at the structural level. The applicability of the proposed equivalent frame model approach is evaluated by how well it replicates the validated continuum model approach results. The two discretization methods described are evaluated using two types of seismic assessment methods. The first seismic assessment method used consists of first performing a quasi-static non-linear pushover analysis (NLPO) on the model. This results in the pushover curve, which describes the global behaviour of the model under an equivalent lateral load based on the fundamental mode shape of the structure. The pushover curve is then used with the N2-method described in EN1998-1 (2004) to assess at which peak ground acceleration (PGA) that the model reaches the near-collapse (NC) limit state. The second seismic assessment method consists of performing dynamic non-linear time-history analyses (NLTH). This method uses recorded accelerograms to impose the inertial forces. The PGA for the accelerogram where the near-collapse limit state is reached is compared to the PGA from the use of the N2-method. The applicability of the pushover analysis in conjunction with the N2-method is evaluated by how well it replicates the PGA found from the time-history analyses and by how well it replicates local failure mechanisms.  Therefore, the main objectives of this project can be described by the following two questions: i. To what extent can the equivalent frame method be applicable as a proper discretization method for pushover analyses and time-history analyses of low-rise unreinforced masonry residential buildings in the Groningen region? ii. To what extent can the non-linear pushover method be adopted to assess the seismic behaviour of low-rise unreinforced masonry residential buildings in the Groningen region? The applicability of the equivalent frame model showed to vary. For describing local failure mechanisms its applicability is poor. Further work on connecting the edge piers to transverse walls is needed. For seismic assessment using the N2-method the applicability of the equivalent frame model approach is sensible. The conservative displacement capacity counteracts the fact that it is worse at describing local unloading, which produced a larger initial equivalent stiffness of the bi-linear curves in comparison to the continuum model. For seismic assessment using the time-history signals, its applicability is possible. While it could show different behaviour in terms of displacement and damping forces, it still showed a similar PGA at the near-collapse limit state for the cases at hand. The seismic assessment of the terraced and detached houses by the N2-method is similar to the seismic prediction by applying time-history analyses. However, there are still some variations in the initial stiffness, force capacity and displacement capacity between these two assessment methods due to the assumptions and limitations in this study. Overall, considering the pros and cons of the quasi-static pushover method, it is deemed applicable during the seismic assessment of the unreinforced masonry structures in the Groningen area. / En stor mängd låga oarmerade murverksbyggnader finns i Groningen, Nederländerna. Allt fler jordbävningar med kort varaktighet har uppmätts i regionen pågrund utav gasproduktion. I området förekommer oarmerade murverksbyggnader som initialt inte var dimensionerade för jordbävningslaster, vilket har resulterat i oönskade skador samt osäkerhet för invånarna. Förekommande låga murverksbyggnader i Groningen kan fördelas i olika grupper beroende på deras egenskaper. Två typer av murverksbyggnader utformade som bostäder uppföljer kraven för att utföra olinjär jordbävningsanalys och har i detta projekt studerats. Typerna som studerats är radhus samt fristående hus. Jordbävningsnalys av byggnader kräver användningen av en diskretiseringsmetod samt en utvärderingsmetod. Diskretiseringsmetoden används för att översätta den mekaniska modellen till en finita elementmodell för numerisk analys. Flera metoder har tidigare visat sig vara applicerbara för utvärdering under jordbävningslaster, men det här projektet studerar konsekvensen från användningen av en kontinuumelement modell (CM) samt en ekvivalent rammodel (EFM) för diskretisering i det generella finita elementpaketet beskrivet i DIANA-FEA-BV (2017). Metoden som använts för att skapa kontinuumelement modeller vart i ett tidigare projekt av Schreppers et al. (2017) validerat mot experimentella resultat och anses därför  representera det fysiska beteendet hos de mekaniska modellerna. Ett förslag för hur ekvivalenta rammodeller ska uppföras i DIANA ges i arbetet av Nobel (2017). Metoden för en kontinuumelement modell använder en konstitutiv lag som utvecklats för utvärderingen av murverksbyggnader under jordbävningslaster. Denna konstitutiva modell fångar skjuv- samt böjbrottmekanismer. Metoden för en ekvivalent rammodell använder numeriskt integrerade balkelement samt nodelement, där båda elementtyper använder en distinkt konstitutiv modell vilket gör att skjuv- samt böjbeteende hanteras individuellt. Den här metoden har som mål att fånga makro-beteendet av elementen. Applicerbarheten av den föreslagna metoden för ekvivalenta rammodeller är utvärderat via hur väl den replikerar resultaten från en kontinuumelement modell. De två diskretiseringsmetoderna jämförs via två metoder för utvärdering under jordbävningslaster. Den första utvärderingsmetoden består av att först utföra en kvasi-statisk olinjär stjälpningsanalys (NLPO) på modellen. Detta leder till stjälpningskurvan, vilket beskriver den globala responsen av modellen under en ekvivalent horisontal last som baserats på första fundamentala moden av bärverket. Stjälpningkurvan används sedan med N2-metoden som beskrivs i EN1998-1 (2004) för att utvärdera vid vilken maximal markacceleration (PGA) som modellen når nära-kollapsgränstilsståndet (NC). Den andra utvärderingsmetoden består av att utföra dynamiska samt olinjära tids-historikanalyser (NLTH). För att göra detta så används accelerogram för att applicera den dynamiska lasten. Den maximala markaccelerationen för signalen där tids-historikanalysen når nära-kollapsgränstilsståndet är jämfört mot den maximala markaccelerationen som fås när N2-metoden används. Applicerbarheten för stjälpningsanalysen tillsammans med N2-metoden utvärderas via hur väl den replikerar resultatet av den maximala markaccelerationen som erhållsfrån tids-historikanalyserna, samt via hur väl metoden replikerar lokala brottmoder. Baserat på detta så kan målen med detta project sammanfattas via dessa två frågeställningar: i. Till vilken grad kan den föreslagna metoden för ekvivalenta rammodeller användas för utvärdering under jordbävningslaster när stälpningsanalyser, samt tids-historikanalyser, utförs på låga och oarmerade murverksbyggnader utformade som bostadsrätter i Groningen? ii. Till vilken grad kan olinjär stjälpningsanalys användas för utvärdering under jordbävningslaster på låga och oarmerade murverksbyggnader utformade som bostadsrätter i Groningen? Applicerbarheten av metoden för ekvivalenta rammodeller visade sig variera. För att beskriva lokala brottmoder så är applicerbarheten låg. Fortsatt arbete som undersöker hur pelarelementen ska kopplas mot de tvärgående väggarna bör utföras. För utvärdering via användandet av N2-metoden så visade det sig att applicerbarheten är rimlig. Den konservativa deformationskapaciteten motverkar det faktum att metoden för ekvivalenta rammodeller är sämre på att påvisa lokal avlastning, vilket i sin tur resulterade i en större ekvivalent initial styvhet för de bi-linjära kurvorna i jämförelse mot metoden för kontinuumelement modeller. För utvärdering när tids-historikanalyser användes så visade applicerbarheten vara rimlig. Samtidigt som det kunde uppstå skillnader i beteende när det kom till deformation samt dämpning, så visade det sig att metoderna fortfarande uppvisade en liknande maximal markacceleration vid nära-kollapsgränstilsståndet för bärverken i fråga. Utvärderingen under jordbävningslast för modellerna när N2-metoden användes visade liknande resultat som när tids-historikanalyserna utfördes. Det förekom dock skillnader i den initiala styvheten, i skjuvkraftskapaciteten och i deformationskapciteten mellan utvärderingsmetoderna från gjorda antaganden samt begränsningar hos arbetet. Som en slutsats när för- samt nackdelar värderas så visade det sig att stjälpningsmetoden är en rimlig utvärderinsgmetod för oarmerade murverksbyggnader i Groningen.

Dagens samhälle har fått en explosiv utveckling som förverkligar mycket som för bara några år sedan var inte mer än fantasier.  Dagens utvecklingsförsprång ställer oss, byggnadskonstruktörer, inför rejäla utmaningar. Den globala folktillväxten ökar väsentligt vilket leder till tätbefolkade städer. Detta utvecklar ett stort utrymmesbehov hos många av oss. Allt detta resulterar i att efterfrågan på stora och öppna planlösningar ökar markant. En av dagens tendenser är att beställare och arkitekter har en benägenhet att tänja på gränserna på maximala spännvidder mellan bärande betongväggar, för bjälklagstjockleken 250 mm. Detta är ett tillfredsställande mått för att klara ljudklass B. Dessutom är det opraktiskt att variera bjälklagstjocklekar inom ett projekt, därför vill man ha uniformitet med samma tjocklek över projektet. För att vi ska kunna förverkliga vårt uppdrag har vi varit tvungna att genomgå en lång beräknings- och undersökningsprocess. I våra beräkningar har vi lagt fokus på två upplagsfall. Det första upplagsfallet ”fri-inspänd” och det andra fallet ”inspänd-yttre gavelvägg”. Första fallet har varit det värsta fallet i och med att vi bara har ett stöd som måste bära hela betongbjälklaget, vilket har varit en stor utmaning. Andra fallet var dock betydligt enklare på grund av de två stöden som utgjorde en stor del av ”arbetet” och lyfter upp bjälklaget, hela tyngden vilade inte på armeringen som i föregående fall. Inte bara spännvidden skall klaras utan även angiven sprickvidd på 0,3 mm. Examensarbetet består av förklarande fakta som är strikt relaterad till efterföljande beräkningar. Alla beräkningar har utförts för hand, utan programstöd. / Today's society has received a degenerate development embodying much that just a few years ago was no more than fantasies. This development sets us, structural engineers, facing real challenges. The global population growth increases significantly leading to densely populated cities. This develops a large space need for many of us. All this results in the increasing demand for large and open floor plans significantly. One of the current trends is that the clients and architects have a tendency to push the limits on maximum spans between bearing concrete walls, slabs for thickness 250 mm. This is a satisfactory measure of the concrete content to manage audio class B. Moreover, it is impractical to vary the slab thickness within a project, so he wants to have uniformity with the same thickness over the project. For us to be able to realize these long spans between bearing walls, we have been forced to undergo a long calculation and examination process. To begin with, we have studied the company's requirements and preferences, based on that, we started joists analysis. In our calculations, we have laid emphasis on two cases. The first circulation fall "free - clamped" and the second, "clamped- outer end wall." The first case has been the worst case, in that we only have one support that must bear the entire concrete slab, which has been a major challenge. Second case was considerably easier due to the two supports which made a large part of "work" and lifts the slab, the full weight rested not on the reinforcement as in the previous case. Not just the span must be met, but also given crack width of 0.3 mm. The thesis consists of explanatory facts that are strictly related to the subsequent calculations. All calculations have been performed by hand, without program support.

Concrete block masonry is a common building material used worldwide, including Canada. Reinforced masonry buildings, designed according to the requirements of recent building codes, may result in seismically safe structures. However, unreinforced masonry (URM) buildings designed and constructed prior to the development of modern seismic design codes are extremely vulnerable to seismic induced damage. Replacement of older seismically deficient buildings with new and seismically designed structures is economically not feasible in most cases. Therefore, seismic retrofitting of deficient buildings remains to be a viable seismic risk mitigation strategy. Masonry load bearing walls are the most important elements of such buildings, potentially serving as lateral force resisting systems. A seismic retrofit research program is currently underway at the University of Ottawa, consisting of experimental and analytical components for developing new seismic retrofit systems for unreinforced masonry walls. The research project presented in this thesis forms part of the same overall research program. The experimental component includes design, construction, retrofit and testing of large-scale load bearing masonry walls. Two approaches were developed as retrofit methodologies, both involving reinforcing the walls for strength and deformability. The first approach involves the use of ordinary deformed steel reinforcement as internally added reinforcement to attain reinforced masonry behaviour. The second approach involves the use of internally placed post-tensioning tendons to attain prestressed masonry behaviour. The analytical component of research consists of constructing a Finite Element computer model for nonlinear analysis of walls and conducting a parametric study to assess the significance of retrofit design parameters. The results have led to the development of a conceptual retrofit design framework for the new techniques developed, while utilizing the seismic provisions of the National Building Code of Canada and the relevant CSA material standards.