The subject of this diploma thesis is a research of bituminous binder modification by fast react-ing polymer SBS. The theoretical part covers an introduction to bituminous binders, their pro-duction, chemical and physical-mechanical properties. The identification of bituminous binders and their use in bituminous mixtures is briefly described. To conclude, current modification methods are described in detail and important modifiers are introduced. In the practical part, three applied tests (softening point, elastic recovery and penetration) are described in detail. The bituminous binders tested (20/30, 30/45, 70/100, PMB 25/55-55 and PMB 45/80-50) and the fast-reacting polymer SBS are introduced. Samples with two weight percentages of SBS, 7,5% and 10%, are produced. Two mixing times, 60 seconds and 600 seconds were used to mix the bituminous binder and SBS. In conclusion, the results are evaluated and commented. Further research suggestions regarding this field are recommended.

The work deals with optimization of the technological properties of cement-sand mixtures. The main objective is to find the correct mixture of the individual components which contribute to the rapid solidification of the mixture, hence shorter dismantling. The content is also of a method of measuring and recording during the plasticity of the mixture. Also assessment of the velocity of hydration heat cement mixture in the initial stage of the solidification process in the course of the strength properties of the mixture. To assess these phenomena was used calorimetric method used for measuring hydration heat cement mixture. Further measurements plasticity mixtures and mechanical and physical methods for measuring the compressive strength with the help of a measuring instrument LRU-D.

The doctoral thesis is focused on the study, research and development of refractories with phosphate bonding. Primary motivation is preparation of phosphate-based binders that can be applied for non-shaped insulating material fabricated by “in situ” foaming. The phosphate binders based on Al2O3-H3PO4 system are one of the most common in refractory technology. The amphoteric nature of the aluminium and its oxides require the setting of Al2O3-H3PO4 binders under the higher temperatures. Application of higher temperatures is necessary to obtain the minimal manipulation strength of as-prepared green bodies. The main goal of the work is preparation of ytrium phosphate-based binders via different preparation techniques. Yttrium based binders would allow phosphate refractory preparation by standard way, i.e via reaction between binder and reactive aggregate, without structural disintegration of foamed material even before getting manipulation strength or the final firing procedure. Yttrium is more basic than aluminium and therefore more reactive in Y2O3-H3PO4 system.. Yttrium oxide is highly refractory material and sintered yttrium monophosphate has excellent properties from the thermal and corrosive stability point of view. This fact should compensate higher price of this material. Experimental part of this work studies the possibilities of binders preparation in Y2O3-H3PO4 system. The mixtures were designed to prepare binding phase Y(H2PO4)3. Products of these reactions were characterized in phase and chemical point of view. In order to study and describe setting and hardening processes of phosphate binders, the products were “in situ” analyzed by the thermal analyses and high-temperature diffraction analysis up to the 1300 °C. High temperature products were then characterized by means of phase and chemical composition and morphology.

Recently, Sustainable engineering has become a necessity due to the limited availability of virgin materials, environmental concerns, and the lack of economic resources. According to the United Nations, "Sustainable engineering is the process of using resources in a way that does not compromise the environment or deplete the materials for future generations." However, developing cost-efficient and long-term road infrastructure has always been a challenge. Therefore, novel solutions are required to extend the pavement life cycle and minimize raw materials utilization to overcome this challenge. This research focuses on integrating the waste material to produce rheological engineered asphalt mixtures as pavement material. This study utilized three wastes, which are Off-spec fly ash (OFA), Reclaimed Asphalt Pavement (RAP), and finally, a bio-oil extracted from Spent Coffee Ground (SCG). OFA is a viable source for recycling due to the quantities produced yearly and deposited in landfills. For many years fly ash has been effectively used as a partial replacement for Portland cement in producing different types of concrete, embankments, and soil stabilization. Most of the underutilized fly ash is Off-Spec. That was the motive behind adopting the OFA in this study. This study aims to investigate the fly ash's interaction with the asphalt binder as an additive rather than a filler. Few studies evaluated this hypothesis regarding fly ash as an additive. Moreover, this research's novelty comes as there is a lack of research evaluating the fly ash-asphalt physio-chemical interaction. RAP utilization in roads infrastructure became a current state of practice. Most state Departments of Transportation (DOTs) have been using RAP at a composition average of about 20% of the mix by mass. This study focuses on maximizing the utilization of the RAP content through using a bio-oil extracted from the SCG as a new promising rejuvenator. Spent coffee ground is not well recycled, and almost six million tons are sent to landfills every year. This waste was found to release methane into the atmosphere; methane is the second-most abundant greenhouse gas and has a global warming potential up to 86 times greater than CO2, which is highly harmful to the environment. In this study, the overreaching goal is to develop a green, innovative, and sustainable approach by recycling three different types of wastes (OFA, RAP, and SCGO) to achieve high-performance asphalt pavements. In addition, this study documents the science-based approach to successfully integrating these wastes as substitutes to the asphalt binder. Results show that some OFAs are associated with improved rheological performance, damage healing, and cracking resistance as an asphalt binder additive. The improvement is attributed to the level of interaction between the binder and the physical and chemical characteristics of the OFA. The use of rejuvenators further improved the aging resistance of the ash blends, suggesting high potential synergy, especially the proposed SCGO rejuvenator, which promotes utilizing it as a promising eco-friendly rejuvenator in the asphalt pavement industry. After engineering a product built by OFA and rejuvenators, these results have been validated by mixtures’ scale testing. 62% optimum RAP content is suggested to be utilized with an 11% dosage of the proposed SCGO rejuvenator as binder replacement. For the new engineered OFA/rejuvenators products, a 30% optimum RAP content is suggested to be used. Finally, Life Cycle Assessment (LCA) is conducted to evaluate the environmental potential of utilizing multi recycled materials in the Hot Mix Asphalt (HMA) industry. The results show a reduction in environmental impacts with RAP utilization and the new eco-friendly products (OFA and SCGO rejuvenator). Shifting HMA plant fuel to natural gas instead of Heavy Fuel Oil (HFO) offers considerable potential environmental benefits. Adopting the Ultrasonic Assisted-oil Extraction (UAE) as SCGO rejuvenator extraction method showed less energy and solvent consumption than the Soxhlet extraction, resulting in less environmental impacts. / Civil Engineering

Nowadays, manufacturing technologies become more and more aware of efficiency and sustainability. One of them is the so called 3D printing. While 3D printing is often linked to plastic, the truth is there are many other materials that are being tested which could have several improvements over plastics.One of these options is stone or concrete, which is more suitable the architecture and artistic fields. However, due to its nature, this new technology involves the use of new techniques when compared to the more commonly used 3D printers. This implies that it could interesting to know how much energy efficient these techniques are and how can they be improved in future revisions.This thesis is an attempt to disclose and analyze the different devices that make up one of these printers and with this information, build a model that accurately describes its behavior.For this purpose, the power is measured at many points and later it is analyzed and fitted to a predefined function. After the fitting has been done, an error is calculated to show how accurate the model is when compared to the original data.It was found that many of these devices produce power spikes due to its nonlinear behavior. This behavior is usually related to switching, and can avoided with different devices.Finally, some advice is given focused on future research and revisions, which could be helpful for safety, efficiency and quality. / Numera blir tillverkningstekniken alltmer medveten om effektivitet och hållbarhet. En av dem är den så kallade 3D­utskriften. Medan 3D­utskrift ofta är kopplad till plast, är verkligheten att det finns många andra material som testas, vilket kan ha flera förbättringar över plast.Ett av dessa alternativ är sten eller betong, vilket är mer lämpligt inom arkitektur och konstnärliga fält. På grund av sin natur inbegriper denna nya teknik användningen av nya tekniker jämfört med de vanligare 3D­skrivarna. Detta innebär att det kan vara intressant att veta hur mycket mer energieffektiva dessa tekniker är och hur de kan förbättras i framtida revisioner.Denna avhandling är ett försök att studera och analysera de olika enheter som utgör en av dessa skrivare och med denna information, bygga en modell som exakt beskriver dess beteende.För detta ändamål mäts effekten på många punkter och senare analyseras och anpassas den till en fördefinierad funktion. Efter anpassning har gjorts beräknas felet för att visa hur exakt modellen är jämfört med originaldata.Det visade sig att många av dessa enheter producerar spännings­spikar på grund av dess olinjära beteende. Detta beteende är vanligtvis relaterat till omkoppling och kan undvikas med olika enheter.Slutligen ges några råd om framtida forskning och revideringar, vilket kan vara till hjälp för säkerhet, effektivitet och kvalitet.

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<p>The dissertation offers a Multiphysics perspective in analyzing emerging metallurgical techniques. Heat transfer, structural deformation, and fluid flow associate with one another in phase-changing materials processing methods. To comprehensively analyze these aspects for an optimized final product, the authors have proposed a numerical mathematical model describing the thermal and geometric progression of the binary alloy casting process. The model is further executed in COMSOL Multiphysics, adapted in two metal manufacturing applications, resistance spot welding (RSW) and binder jet printing (BJP). </p><p>Resistance spot welding is a well-adapted metal sheeting joining technique with comparably limited modeling and simulating research. The heat transfer module and geometric deformation module are applied to the simulation of RSW to discuss the thermal gradient development of the welding zone. The model was further calculated and verified through a case study with Python. </p><p>BJP is a rapidly developing additive manufacturing method. The novel 3D printing technique brings challenges in post-processing geometric control and material selection limitations. Multiphysics simulation serves as an excellent tool in process parameters analysis and quality control. This dissertation focuses on the sintering process of BJP of binary alloy powders. Melting and solidification mathematical models were implemented in COMSOL, where the sintering shrinkage rate could be calculated. The shrinkage rate was further verified through experimental analysis of binder jet printed samples. </p><p>Microstructural analysis on sintered binder jet printed parts was performed to assess the validity of BJP to substitute the die casting method for manufacturing of valvebody. Sintering shrinkage and metallurgical analysis have been performed on the green and sintered BJP samples. After sintering, the final part achieved 98% density, and the integrity of the designed channels was preserved. The shrinkage analysis has indicated the effect of printing orientation and sintering orientation on the geometry and metallurgy of the final products. Microstructure analysis on the cross-sections of the sintered products also indicates the various defects induced from biner jet 3D printing. </p><p>The research aims to provide a systematic rheology analysis of the phase transformation process of binary alloys. The dissertation has connected the physical, mathematical modeling with 15 </p><p><br></p><p>simulative modeling through the rheological evaluation of phase-changing manufacturing techniques. The connections were conclusively verified through empirical studies, including case assessment and experimentation. The research aims to offer universally applicable models that can be applied to phase-changing metal processing techniques. </p>

The aim of this work was to systematically study how the microstructure evolution is affected by the carbon activity in WC-Ni cemented carbides. Seven WC-9.59at%Ni alloys with different carbon activity were sintered at 1500 °C. From investigating these alloys, the carbon window has been experimentally evaluated using light optical microscopy and compared to theoretical carbon window calculated using Thermo-Calc. The overall microstructure of cross sections and raw surfaces have been investigated using scanning electron microscopy. Finally, the WC grain size and distribution have been evaluated using electron backscatter diffraction. It was found that the experimental carbon window was slightly wider than the theoretical carbon window. The WC grain size increased and the grain size distribution got wider with increasing carbon activity. In addition, the largest WC grains showed the largest grain growth by increasing carbon activity. By comparing the present results of grain size and distribution of WC-Ni to previous results of WC-Co, it was found that the WC grain growth was more pronounced and more influenced by the carbon activity.

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