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New procedures for evaluating concrete in existing construction
Juřenová, Jana ; Kocáb, Dalibor (referee) ; Cikrle, Petr (advisor)
This bachelor thesis seeks to increase the awareness of the possibility of using the ultrasonic pulse method for the diagnosis of building structures. It emphasises the use of non-destructive methods, highlighting their ability to provide comparable results to traditional destructive methods of assessment, whilst minimising interference to the structure. The work includes reporting on the procedures for determining the characteristic compressive strength of concrete in existing structures as defined in EN 13791, updated in 2021. The work focuses primarily on calibrating results from non-destructive indirect measurements with those obtained destructively using core borings.
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Design and analysis of reinforced concrete or masonry structures
Skočdopole, Jakub ; Švaříčková, Ivana (referee) ; Požár, Michal (advisor)
The bachelor's thesis deals with the static solution of the reinforced concrete ceiling slab and the inclined column of a 2-storey multi-storey building. The first part is devoted to the design of a point-supported plate, a cross-reinforced plate and an inclined column inclined by 15° from the vertical structure according to the limit state method. A spatial 3D model was created in the SCIA Engineer program, which was used to determine the internal forces in the structure. The correctness of the model results was verified by the sum of moments method. The second part deals with the study of the influence of the slope of the columns on the structure, when one row of columns in the 2nd floor was inclined and then the effect of this change on the structure and the static assessment were compared. Reference slopes chosen for the study: 0°; 15°; 30°; 50°, a partial spatial 3D model of the structure was created for each variant. The appendix of the bachelor's thesis is a detailed static calculation according to valid ČSN EN standards, drawing documentation and a study of the influence of the inclination of one row of columns on the reinforced concrete structure.
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Modelling of shear strength of concrete beams
Večeře, Jakub ; Lehký, David (referee) ; Novák, Drahomír (advisor)
The bachelor thesis deals with the modeling of reinforced concrete beams and compares their load-deflection (L-D) curves with curves obtained in an extensive experiment at the University of Lodz under the guidance of Prof. Renata Kotynia, Dr.Hab. For comparison, data from two selected beams with identical shapes, lengths, and concrete strengths were used – one reinforced with steel and the other with a composite made of glass fiber-reinforced polymer (GFRP). Modeling is carried out using nonlinear fracture mechanics of finite elements (2D) in the ATENA software. Emphasis is particularly placed on accurately modeling the bond between concrete and reinforcement. Modeling was performed in both 2D and 3D.
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Design of a 3D print head for mixing additives into cement mixtures
Vícha, Daniel ; Dočkal, Aleš (referee) ; Škaroupka, David (advisor)
The subject of the thesis is the design of a 3D printing head for cement-composite mixtures (concretes). The device enables the addition of the basic component of the mixture by using a liquid solidification accelerator, followed by active homogenization of the mixture and dosing at the printing site. 3D printing of cementitious mixtures often leads to a loss of buckling stability of the printout. Therefore, it is necessary for the printed material to contain additives that accelerate the solidification of the mixture. However, these additives can cause clogging of the hoses when the mixture is pumped into the print head due to premature solidification. Hence, a more suitable solution is to mix these additives in the print head itself. The objective was to develop a 3D print head that allows for homogeneous mixing of the additives in the mixture, thereby eliminating complications associated with pumping. A working prototype of the print head was designed, which consists of a mixing and extrusion chamber. The mixing efficiency of this prototype was verified through numerical simulations using Particleworks. Subsequently, the prototype underwent a mixture experiment without a solidification accelerator to investigate pumpability through the printhead. Based on the numerical simulations, it was determined that the proposed prototype provides sufficient homogeneity of the solidification accelerator with the cement mixture, which should resolve the issues associated with pumping the accelerated mixture. By having a separate mixing chamber, the mixing efficiency can be controlled by adjusting the speed of the motor that drives the mixing shaft. The print head was designed to allow extrusion to be interrupted during print head passes. This was achieved by extruding the mixture into the open space of the chamber using a screw feeder. Therefore, based on the conducted experiments and numerical simulations, it can be concluded that the developed print head has the potential to enhance the quality of 3D printing of cement mixtures and eliminate the problems associated with pumping.
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Design of a single span prestressed bridge
Daněčková, Monika ; Panáček, Josef (referee) ; Nečas, Radim (advisor)
This bachelor thesis aims to design a prestressed bridge with one span. The plate girder bridge was selected from the given alternatives. The load effects were calculated by hand calculation using the member model and in SCIA Engineer 22.0. using the slab model. Subsequently, the structure was assessed for limit states.
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Community housing in Brno-Komín
Raková, Markéta ; Pekár, Pavel (referee) ; Novák, Antonín (advisor)
The subject of the diploma thesis was the design of a multifunctional building within the framework of community housing, located in the area of former gardens along Řezáčova Street in the urban district of Brno-Komín, at the intersection between the existing urban structure of the original panel housing estate and open countryside. The enclosed area currently forms a barrier between the cycling and walking route under Palacký Hill and the existing development. This presents an opportunity to open up and make this area more accessible to people. Overall, there are five residential buildings proposed in the area, each consisting of five above-ground floors, with the top floor being setback with vegetated roofs and terraces. The semi-open composition of the buildings responds to the existing urban structure and the panel housing development. It creates a space accessible not only to community residents but also to the public. The design of the multifunctional building is based on key principles such as Baugruppe construction, sustainability, prefabrication, and the associated speed of construction and variability of proposed interior spaces. It also emphasizes creating a place that fosters interaction among community residents. Furthermore, the aim is to work with wood as a significant element for reducing CO2 emissions and to influence the architect's and builder's attitude towards this material in terms of fire and environmental considerations. For these reasons, the building is designed as a hybrid timber and concrete structure. This system allows for fast, flexible, and cost-effective construction and an efficient combination of the properties of individual materials. The communication system of the building is designed as a gallery, offering additional meeting opportunities for residents for the purpose of community living. Operationally, the building is designed as a multifunctional structure with a predominant residential function. Common areas in the ground floor of the building are available for community residents in the form of co-working spaces, a café, and community workshops. The last setback fifth floor is also dedicated to the building's users, featuring wellness areas and an apartment for accommodating potential visitors of the residents. Users also have access to other shared spaces such as a bicycle room, stroller storage, and laundry room.
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Technological stage of the rough superstructure of an library in Veselí nad Moravou
Vančo, Lenny ; Průcha, Aleš (referee) ; Šlanhof, Jiří (advisor)
The aim of my bachelor's thesis is to develop a technological project for the technological stage of the rough upper structure. For this work, I chose the construction of a new library in the town of Veselí nad Moravou. The project was created by Ing. Katarína Božková as part of her diploma thesis at the Faculty of Civil Engineering at the Brno University of Technology. It is a public amenity building. The library also includes a bookstore and a café. The technological prescription is prepared for reinforced concrete monolithic ceilings. Additionally, I will address the logistics of transportation routes, the bill of quantities, the design of the construction site setup, the selection of machinery, work safety, the inspection and testing plan, and the schedule plan.
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Structural design of the industrial building for increased loads
Landa, Tomáš ; Olšák, Martin (referee) ; Klusáček, Ladislav (advisor)
The bachelor thesis deals with the design of a ceiling structure for a load of 15 kN/m2. The design was prepared on the basis of the submitted documents. A preliminary design of the structure and its elements was developed for the given problem. The structural analysis was performed in SCIA Engeneer software system (including manual control by simplified method). The result of this bachelor thesis is a static calculation and design documentation of the designed structures.
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Study of the possibilities of using superabsorbent additives in concrete
Kubíček, Matyáš ; Jančář,, Josef (referee) ; Hela, Rudolf (advisor)
This bachelor's thesis deals with the study of self-healing of cracks in cement composites. In the theoretical part, four chapters describe the mechanisms that influence the durability of concrete or can extend it. In the first chapter, I deal with concrete additives that affect the water consumption in concrete. This chapter is focused on plasticizers. In the second chapter, I deal with the treatment of concrete, how long to treat it and what are the ways of treating it. In the third chapter, I write about rehabilitation, about the additional life extension of building structures using various technologies and mechanisms. The fourth and last chapter of the theoretical part is the most comprehensive and discusses the self-healing mechanisms of concrete with the help of several types of microorganisms that heal cracks with their products. Then about calcium lactates, which are often combined with microorganisms to improve the effects of self-healing. About non-metallic polymer fibers, both natural and synthetically produced, added to concrete to improve properties. In the last subsections, I mention the use of colloidal SiO2 solutions and especially superabsorbent polymers, the investigation of which plays a significant role in this thesis. In the experimental part, the influence of the amount of superabsorbent additive in concrete on the ability of self-healing is investigated. The ability to heal cracks, which will be artificially created after mixing the concrete mixture, when placing the concrete in the forms, is investigated. Furthermore, the influence of the effect of the superabsorbent additive in different deposits will be investigated. Subsequently, the samples will be tested for tensile strength after bending and compressive strength.
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