Currently, increasing reinforced concrete structures and concrete structures that require repair in the form of remediation. The master’s thesis deals with the development of repair mortars with resistance to high temperatures, which would allow the re-profiling of the fire damaged parts of the structures and restore its function. Development of repair mortars is based on a literature review of articles dealing with research materials resistant to high temperatures.

In this time are for design of wooden elements available simplified procedures for fire modeling which defines ČSN EN 1991-1-2. But it is not experimentally tested the impact of adhesive on the final value of fire resistance of laminated panels. This diploma thesis solves basic normative practices that could explain the durability of glue bond against increased temperatures. in the practical part will be undertaken to experimentally assess the impact of various kinds of adhesive-based (epoxy, formaldehyde, PUR and EPI) on the glued bond durability against increased temperature. Glued joints that will be subjected to gradual temperature exposure in order to assemble the dependence of the temperature influence on the final strength of the joint according to the type of adhesive.

The thesis is focused on the current issues of concrete resistance to high temperatures. The theoretical part has been processed the changes taking place in the individual components of concrete and changes affecting the physical - mechanical properties of concrete and color-changing effects manifesting high. In the experimental part of the load was, carried concrete test samples to a temperature of 400 ° C, 600 ° C and 800 ° C. After the thermal load, has been on test samples tested changes in physico - mechanical properties, especially concrete compressive strength, water absorption but also a visual assessment of the concrete surface

<p>Savremene metode procene ponašanja konstrukcija u uslovima požarnih dejstava zasnivaju se na razvoju složenih numeričkih modela. U okviru disertacije, računski modeli razvijeni su korišćenjem komercijalnog programskog paketa ANSYS Workbench 16.0. Validacija i verifikacija modela sprovedeni su na osnovu rezultata eksperimentalnih i numeričkih istraživanja dostupnih u literaturi. Parametarskom analizom, utvrđen je uticaj požarnog scenarija, tipa agregata za spravljanje betonske mešavine, početnog nivoa opterećenja i prethodnog uticaja seizmičkog dejstva, na odgovor armiranobetonskih okvirnih konstrukcija u toku požara.</p> / <p>Contemporary methods for assessing the structural behavior under conditions of fire actions are based on the development of advanced numerical models. In the framework of dissertation, computational models are developed using commercial software package ANSYS Workbench 16.0. Validation and verification of the models are carried out based on the results of experimental and numerical research available in the literature. Parametric analysis is used to determine the influence of fire scenario, type of aggregate used for preparation of concrete mix, initial load level and the previous effect of seismic action, on the response of reinforced concrete frame structures during fire.</p>

Die Verwendung von Endlosfilamenten aus Carbon als Bewehrungsmaterial für Beton, sogenannter Textilbeton, bietet die Möglichkeit der Sanierung und der Verstärkung bestehender Stahlbetonkonstruktionen. Dabei muss die Frage nach dem Feuerwiderstand von derart verstärkten Tragwerken beantwortet werden. Aufschluss darüber liefern Brandversuche. Mit Textilbeton verstärkte Stahlbetonplatten haben in Brandversuchen nach der Einheits- Temperaturzeitkurve bei 33 % der Traglast mehr als 60 Minuten standgehalten. Bei 50 % der Traglast kam es nach einer Branddauer von 55 Minuten, bei 65 % nach 30 Minuten, zu einem Zugversagen der textilen Verstärkungsschicht. Bei während des Brandes unbelasteten bzw. gering belasteten Platten lagen die im Anschluss ermittelten Resttragfähigkeiten bei 65 % der Bruchlast nach 30 Minuten Branddauer bzw. bei 50 % der Bruchlast nach 60 Minuten Branddauer. Während und nach der Beflammung waren zunehmende Durchbiegungen und Rissbreiten erkennbar. Es traten aber keine Abplatzungen auf, weshalb die Verstärkungsschicht aus Textilbeton als zusätzliche Betondeckung für die Stahlbewehrung angerechnet werden kann. Diese außerordentlich positiven Ergebnisse zeigen, dass für verstärkte Konstruktionen Feuerwiderstandsklassen von F60 bzw. R60 ohne zusätzliche Maßnahmen erreicht werden können. Dies ist von hoher Relevanz für die wirtschaftliche Anwendung dieser Verstärkungsmethode. Für ein umfassendes Verständnis der Interaktion zwischen den Bewehrungen Textil und Stahl sowie der Versagensmechanismen während des Brandes, sind weitere Erkenntnisse über die mechanischen Eigenschaften von Textilbeton im Hochtemperaturbereich nötig. Auch der Einfluss der Oxidation des Carbons konnte nicht abschließend beurteilt werden. / Using endless carbon filaments for concrete reinforcement, so called textile reinforced concrete, the possibility of reconstruction and strengthening of existing concrete structures arises. The question concerning fire resistance of structures strengthened like this has to be answered. Fire tests provide answers. Steel reinforced concrete slabs strengthened with textile reinforced concrete loaded with 33 % of ultimate load survived an ISO-fire for 60 minutes. Loaded with 50 % and 65 % of ultimate load the slabs failed after 55 minutes and 30 minutes of fire exposure due to tension failure of the textile reinforcement layer. Slabs not loaded or with a low load level during fire exposure showed remaining bearing resistances of 65 % of ultimate load after 30 minutes and 50 % of ultimate load after 60 minutes of fire exposure. During and after fire exposure rising deflections and growing crack widths were observed. However no spalling occurred. Therefore the textile reinforced concrete layer can be taken into account as concrete covering for the steel reinforcement. Those extraordinary positive results document, that reinforced concrete structures with additional fibre reinforced concrete can achieve fire resistance classes of R60 without additional provisions. To achieve comprehensive understanding of interaction between steel and fibre reinforcement and failure mechanisms in case of fire more knowledge concerning the mechanic properties of fibre reinforced concrete at high temperatures is essential. The influence of oxidation of the carbon fibres could not fully be answered.

Historically, energy use in the operational phase has accounted for most of a building’s climate impact. This has been changed in recent decades because there has been a focus on developing energy-efficient buildings. A larger part of a building’s climate impact is caused by material manufacturing and production. To reduce a building’s climate impact alternative insulation materials can be used, for example hemp fibre insulation which is an organic and non-toxic material. The aim of this study is to find out if hemp fibre insulation can be implemented as a standard insulation material. By examining what factors are vital when choosing an insulation material this work intends to find out if the insulation properties of hemp insulation can fulfill the requirements by the constructor. To fulfill the aim, a combination of interviews, surveys and theoretical studies was used. The most crucial aspects when choosing insulation material are fire resistance, thermal conductivity and health aspects for the construction workers. The benefits with hemp insulation are primarily the negative emissions of carbon dioxide seen from a life cycle perspective, the possibility to cultivate the product within Sweden, its reusability and recyclability and that the insulation material are free from hazardous substances. The disadvantages are higher thermal conductivity, higher market price, lower fire resistance and limited accessibility on the Swedish market. Due to the disadvantages, it is difficult to implement hemp insulation as a standard insulation material today. The conclusions are that the environmental impact is not decisive for an entrepreneur today when choosing insulation material. However, it will most likely become a more essential factor in the future. Improving the building sector’s knowledge regarding hemp insulation, will presumably increase the usage of it. Although, for hemp insulation to become a competitor in the future, it is substantial to increase its fire resistance and the accessibility on the Swedish market. The development of the material and the market may be a contributing factor to achieve the global and national environmental goals.

The current Swedish building code (Boverkets Byggregler, BBR) is very strict regarding fire-safety in high-rise timber structures because of the heightened risk of fast flame spread or structural failure in case of fire. Fire safety solutions, that are used in timber structures must therefore be optimal to contain flames from spreading in the event of fire. The current building code requires that load-bearing elements must withhold their load-bearing capacity for 60 minutes under fire. The purpose of this study was to research the effect that different fire-retardant surface treatments, have on fire protection of a load bearing, laminated timber element. Thereafter, a short analysis was made on the environmental impact of the fire-retardant surface-treatments in question and finally, a cost analysis and comparison were conducted with regard to different fire-safety solutions such as fire-resistant gypsum board and a combination of fire-resistant gypsum board and stone-wool. The methods used in this study are a combination of theoretical reviews and theoretical calculations. A theoretical review was conducted in order to collect the information needed to understand the behavior of timber under fire, the impact of fire-resistant surface treatments on fire protection, and the environmental impact of the actual surface treatments. Therefore, a series of theoretical calculations were made in accordance with European standards (Eurocodes) in order to present the impact in numbers. The calculations made were concerning a laminated timber beam with the dimensions of 145 x 450 x 6000 [mm] and took into account the remaining cross-section of the timber element under various timestamps during fire with regard to fire-stage, charring-rate, and fire coating. The results of this study indicate that the moment-capacity and shear-capacity of an untreated beam decrease constantly under fire and does not fulfill the requirements of the Swedish building code. Thereafter, in case that the same timber beam is fire-treated with a fire-retardant surface treatment. The moment-capacity is observed to increase in the first stage of fire, were the fire-protection of the surface-retardant treatment is still in action. Therefore, after fire-protection ceases, the moment-capacity of the timber beam is calculated to decrease in different rates with regard to fire-stage. The shear capacity of the treated beam is calculated to decrease under fire with a time-displacement of 30 &amp; 60 minutes in comparison to the untreated element. The conclusions are that the studied surface treated timber beam and the actual fire treatments fulfill the requirements of the Swedish building code. Have insignificant environmental impact and are in comparison to other solutions cheaper.

I takt med en ökad miljömedvetenhet har träbyggnation börjat premieras allt mer och sedan lagändringen 1994 som innebar att det blev tillåtet att uppföra höga hus med trästomme har utvecklingen snabbt gått framåt. Att korsvis bygga upp skikt av brädor och sammanfoga dessa till element har visat sig skapa en produkt med hög hållfasthet och låg vikt som är idealisk som stommaterial vid byggnation av stora och höga hus i trä. Dessa element har många namn men kallas ofta korslimmat trä och kommer i arbetet benämnas CLT, cross-laminated timber. Dess användning har ökat markant i Sverige och Europa de senaste decennierna och än ses ingen stagnation på efterfrågan.   Denna rapport behandlar relevanta teoretiska områden som måste tas i beaktning vid branddimensionering som exempelvis brandförloppet i en brandcell samt hur brandsäkerhetsklasser och brandtekniska byggnadsklasser bestäms och fastställs. Dimensioneringsmetoder av laster och hållfasthet i både brottgräns och i brandfallet förklaras genomgående för skapa en tydlig bild av hela branddimensioneringsprocessen. Brist på direkt information om hur hållfastheten av resttvärsnitten ska behandlas och beräknas har gjort arbetet utmanande men med hjälp från Maija Tiainen från Sweco structures Helsingforskontor har arbetet kunnat färdigställas och bli fullständigt.   Den viktigaste delen i rapporten är dock själva inbränningen och förkolningen av elementen som beräknas med hjälp av två olika metoder. Den ena återfinns i den europeiska standarden Eurokod 5: del 1-2 och den andra, som baseras på den absolut senaste forskningen gällande träkonstruktioner och brand, är hämtad från handboken Brandsäkra trähus version 3. Den senare metoden kommer ligga till grund för en uppdatering av Eurokod 5 i framtiden.   För att kunna jämföra de två metoderna och ge en nyanserad bild av dessa valdes fyra väggtyper ut som beräknades med samma förutsättningar. Det vill säga skyddade med två lager gips och utsatta för en 90 minuters ensidig standardbrand.   Resultatet visade på skillnader mellan metoderna där en tydlig och definitiv sådan var storleken på resttvärsnittet då det icke lastupptagande skiktet, , visade sig vara mycket större i beräkningarna enligt metoden i Brandsäkra trähus version 3. På grund av elementens uppbyggnad, korsvis lagda skikt där endast vartannat skikt är lastbärande, betyder detta inte nödvändigtvis att det resulterar i en skillnad gällande bärförmåga i brandfallet mellan de två metoderna.   Trots att metoden i Brandsäkra trähus version 3 är mer konservativ gällande bärförmåga och leder till ett mindre resttvärsnitt efter brand anser författarna att denna metod bör användas i väntan på en inarbetning av metoden i Eurokoden. Detta då den till skillnad från Eurokoden är utformad och framtagen för att kunna behandla CLT och då säkerheten är viktigast i sammanhanget måste brandens ökade påverkan på materialet enligt den senaste forskningen tas på allvar och tvärsnittet dimensioneras därefter. / In recent years, a growing environmental awareness have led to an increase in timber buildings and since the 1994 amendment that made it possible to build tall houses with timber structures the progress in the field have seen an substantial increase. To build an element of perpendicularly placed layers of solid-sawn lumber have proven to be an effective way to obtain a product with good strength-to-weight ratio that is ideal for use in tall timber buildings. These elements go under a lot of different names but are often referred to as cross-laminated timber and will be called CLT in this report. The use of this product have these past decades increased substantially both in Sweden and in Europe and the demand does not seem to stagnate nor decrease in the near future.   The report is comprised of relevant theoretical sections that must be taken into account when designing a structures fire protection such as the development of a fire in fire compartment, how to define and determine a structures class of fire resistance and hence required fire protection time for said structure. The basis of design in regards to loads and compressive/flexural strength of the material is thoroughly explained in order to account for the whole fire protection design processes. The lack of information regarding compressive and flexural strength of the residual cross-section was challenging but with the help from Maija Tiainen from Sweco structures Helsinki office the report could be completed.   The most important part of the report is the theory and calculation with regards to the charring depth which is calculated by two different methods. The first one is presented in the European standard Eurocode 5: part 1-2 and the other one, that is based on the latest scientific knowledge with regards to timber structures and fire, is found in the technical guide Brandsäkra trähus version 3. The aforementioned method will form the basis for the upcoming update of Eurocode 5.   In order to be able to compare the two methods four wall types was chosen and designed based on the same conditions. Namely protected by two layers of gypsum plasterboards as fire protection and exposed to a 90 minutes one-sided standard fire.   The result showed differences between the methods where a clear difference was the size of the residual cross-section due to the fact that the zero-strength layer, , was notably larger when calculating with the method presented in Brandsäkra trähus version 3. This does not necessarily affect the elements bearing capacity when calculating with the two different methods due to the elements perpendicularly placed layers where only every other layer is load bearing.   Although the method presented in Brandsäkra trähus version 3 are more conservative with regards to bearing capacity and will lead to a smaller residual cross-section the authors of this report recommend the use of said method pending incorporation into the Eurocode. The motivation for this suggestion is that the method is designed to explicitly handle CLT and since safety is the most important aspect in this context it is vital to acknowledge the apparent increased affect from a fire on the material according to the latest scientific knowledge and design the cross-section accordingly.

No / This paper presents experimental results of temperature distribution in fire in four typical types of steel-concrete composite joint (web cleat, fin plate, flush endplate and flexible endplate) with different fire-protection schemes. The test specimens were unloaded and the steelwork of each joint assembly was exposed to a standard fire condition [ISO 834, 1975: Fire Resistance Tests, Elements of Building Construction, International Organization for Standardization, Geneva] in a furnace. In total, 14 tests were conducted, including 4 tests without any fire protection and 10 tests with different schemes of fire protection. The main objective of these tests was to investigate the effects of three practical fire-protection schemes as alternatives to full fire protection of the entire joint assembly. The three alternative methods of fire protection were: (1) protecting a segment, instead of the entire length, of the beams; (2) unprotected bolts and (3) protecting the columns only. The main results of these tests are: (1) if all the steel work (excluding the bolts) in the joint assembly was protected, whether or not protecting the bolts had very little effect on temperatures in the protected steelwork other than the bolts. The bolt temperatures were higher if they were not protected than if they were protected, but the unprotected bolt temperatures in a joint with fire protection to other steelwork were much lower than bolt temperatures in a totally unprotected joint; (2) as far as joint temperatures are concerned, protecting a segment of 400 mm of the beam was sufficient to achieve full protection and (3) if only the column was protected, only the joint components that were in the immediate vicinity of the column (such as welds) developed noticeably lower temperatures than if the joint assembly was unprotected, but due to heat conduction from the unprotected steel beams, these temperature values were much higher than if the joint assembly was protected. Furthermore, the column temperatures in the joint region were much higher than the protected column temperatures.

El empleo de pilares tubulares de acero rellenos de honnigón (CFT) ha crecido en las últimas décadas, debido a su excelente comportamiento estructural, que aprovecha el efecto combinado del acero y honnigón trabajando juntos. Esta asociación ofrece una serie de ventajas que hacen de las columnas CFT una solución interesante: su alta capacidad portante o su eficiente tecnología constructiva pueden citarse entre sus beneficios ampliamente conocidos, que se completan con una elevada resistencia al fuego sin necesidad de protección externa. Tradicionalmente, se han venido utilizando secciones huecas circulares, cuadradas y rectangulares para formar estas columnas compuestas. Adicionalmente, la sección elíptica ha sido recientemente introducida dentro de la gama de secciones de acero huecas disponib les comercialmente. Su atractivo estético y su reducida intrusión visual, junto con sus ventajas estructurales asociadas a secciones con diferentes propiedades en sus ejes fuerte y débil, hacen a las secciones elípticas de gran interés para los diseñadores. En esta tesis se estudian pi lares CFT de sección tanto circular como elíptica. Pese a que el comportamiento de los pilares CFT a temperatura ambiente ha quedado bien establecido en los últimos años, en situación de incendio la degradación de las propiedades del material da lugar a un comportamiento extremadamente no lineal de estas columnas compuestas, lo que hace dificil predecir su fallo. El estado del arte en el campo del comportamiento frente al fuego de columnas CFT se revisa en esta tesis, mostrando que es necesario profundizar en su investigación para una comprensión completa del funcionamiento de tales columnas en situación de incendio. En el caso de las secciones elípticas, este trabajo constituye una investigación novedosa. El comportamiento frente al fuego de los pilares CFT se estudia en esta tesis por medio de un modelo realista tridimensional de elementos finitos. Los valores adoptados de los parámetros del / Espinós Capilla, A. (2012). Numerical analysis of the fire resistance of circular and elliptical slender concrete filled tubular columns [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/17579