O cimento ósseo, utilizado para a fixação de componentes protéticos nas cirurgias de substituição articular, mais resistente às forças de compressão do que às forças de tração, tem suas propriedades mecânicas alteradas por vários fatores entre esses a formulação comercial e o método de preparação empregado. É o objetivo deste trabalho avaliar comparativamente as propriedades mecânicas à compressão de duas formulações comerciais de cimento ósseo preparadas manualmente e a vácuo, segundo as instruções do fabricante. Um conjunto de moldagem confeccionado em aço inoxidável permitiu preparar 48 corpos de prova para cada grupo experimental, totalizando 192 corpos de prova, que foram testados na Máquina Universal de Ensaios, tendo as especificações baseadas nas normas ISO 5833 e ASTM F451-86. A elaboração do diagrama tensão x deformação de cada grupo experimental analisou as propriedades mecânicas do cimento ósseo quanto ao módulo de elasticidade, tensão e deformação no limite de proporcionalidade, entre grupos de mesma formulação comercial e entre os grupos com mesmo método de mistura. Analisados estatisticamente pelo método de Variança de Kruskal-Wallis (p ≤0,001) e pelo método de Dunn's (p ≤0,05). Quanto ao módulo de elasticidade, o grupo 2M foi o que apresentou maior módulo, 1563 MPa, valor estatisticamente significante (p ≤ 0,05) em relação aos grupos 1M, 1V e 2V. Para a tensão no limite de proporcionalidade os grupos 1M (39,40 MPa) e 2V (39,65 MPa) foram os maiores valores de tensão no limite de proporcionalidade, não havendo diferença estatisticamente significante entre eles, mas essas diferenças foram significativas quando comparadas aos grupos 1V e 2M. A deformação no limite de proporcionalidade de maior valor percentual foi para o grupo 1M, 3,36%, sendo esta diferença estatisticamente significante quando comparado ao grupo 2M. Os testes de resistência à compressão do cimento nacionalizado e importado, preparados manualmente e a vácuo, mostraram não haver diferença importante entre os dois tipos de cimento ósseo, nem entre as duas formas de misturá-los. / The bone cement used for the fixation of the prosthetic components in the surgeries of joint replacement, more resistant to the compression than to the traction, has its mechanical properties altered by several factors among those the commercial formulation and preparation employee's method. It is the objective of this work to evaluate the mechanical properties to the compression of the two commercial formulas of bone cement manually prepared and using vacuum, according to the manufacturer's instructions. A molding set was made in stainless steel and it allowed for the preparation of 48 bodies of proof for each experimental group, adding up to 192 proof bodies total which were tested in the Universal Rehearsal Machine, with the specifications based on the ISO 5833 and the ASTM F451-86 regulations. The elaboration of the diagram "tension vs. deformation" of each of the experimental group analyzed the mechanical properties of the bone cement in relation to the elasticity module, tension and deformation on the proportional limit among the groups with the same commercial formula and among the groups with the same mixture method. Analyzed statistically, by Kruskal-Wallis's method of the variation (p ≤0.001) and by the Dunn’s method (p ≤0.05). Regarding the elasticity, the group 2M was the one with the highest module, 1563 MPa, a statistically significant value (p ≤0.05) in relation to the groups 1M, 1V and 2V to the tension at the limit of the proportionality, there is no significant differences among them, but these differences were relevant when compared to groups 1V and 2M. The deformation at the limit of the proportionality of the highest percentage was to group 1M, 3.36%, being this the relevant statistical difference when compared to group 2M. The resistance tests to the compression of the national and international cement prepared manually and by vacuum show that there is no important difference between the two kind of bone cement, and neither between the two ways of mixing them.

Estimating the delayed strains in concrete, namely creep and shrinkage is very important to asses the condition of the structure. Time dependent deformations in concrete, both creep and shrinkage, play a critical role in prestressed concrete structures, such as bridge girders, nuclear containment vessels, etc. These strains result in lossess, through release of prestress, and thereby influence the safety of these structures. Recognizing the role of free and bound moisture movement is the primary ingredient responsible for the development of both creep and shrinkage stains as well as the degradation of concrete under high temperature, the present study has also examined the effects of high temperature on concrete degradation, experimentally and also analytically in the same modelling framework. Fire in concretes deteriorates mechanical properties of the material and lead to col-lapse under loads. Two types of spalling occur in concrete when exposed to high temperature, namely explosive and thermal spalling. Explosive spalling occurs once the hydrostatic stress (developed due to pore pressure) exceeds the tensile strength of the concrete. Where as thermal spalling of concrete happens due to degradation of material properties (elastic modulus, compressive and tensile strength) when exposed to high temperature due to decomposition of chemical bonds that release the bound water. The present study comprises of an experimental and analytical program to assess the levels of creep and shrinkage in different concrete under various loads and environmental conditions. Deformations due to high temperature in di erent concretes forms another component of the present study. Total six concrete mixes has been studied to investigate and asses the extent of creep and shrinkage taking place in the concretes under different environmental conditions, load level and age at loading. In total six mixes, three that are self compacted concrete mixes (35MPa, 55MPa and SCC70MPa), a high volume y ash concrete mix ( 45 MPa) and two normal concrete mixes (35 MPa and 45 MPa) have been considered in this study. To study the high temperature effects, the same mixes considered in the creep and shrinkage study and in addition a heavy density concrete mix (25 MPa) is used. A normal concrete having a 28 day uniaxial compressive strength of 45 MPa after proper curing, referred to as M45 concrete, was one of the six mixes. Likewise a heavy density concrete designated as H25, corresponding to a 28 day uniaxial compressive strength of 25 MPa was another mix that was studied and was made using iron ore aggregate and iron ore sand. A concrete having high volume y ash replacing cement designated as F45 offered a 28 day strength of 45MPa. Three self-compacting concretes with uniaxial compressive strengths of 35, 55 and 70 MPa were designated as SCC35 SCC55 and SCC70, respectively is studied for creep, shrinkage and high temperature effects. F45 concrete shows lower creep strain when compared to normal M45 concrete, under similar casting, curing and testing condtions. This is due to increase in stiffness of y ash based concretes with time. Where as in shrinkage it is observed that a little higher strain takes place in F45 at initial ages than in M45 concrete mix for the same conditions. But in the later age, F45 concrete shows a decreasing rate of shrinkage strain. This is because, water to cement ratio of y ash concrete is higher than the M45 concrete. The SCC35 concrete shows higher creep and shrinkage than M35 concrete even though both the concretes have the same water cement ratio. This difference comes from the aggregate cement ratio (a/c). The lower the aggregate cement ratio, the higher the creep and shrinkage. M35 concrete has a higher aggregate cement ratio than the SCC35. Concretes exposed to higher temperature and lower humidity shows higher creep and shrinkage due to its higher rate of drying. An analytical model has been developed to simulate the drying phenomena in concrete based on poromechanics. The hydration effects of blended cements is considered while developing the model. This models prediction of degree of hydration, temperature and relative humidity is used to model creep and shrinkage in concrete. To model creep and shrinkage, micro prestress solidi cation theory is implemented and validated with the present experimental results. The model is able to predict the drying phenomena of concrete realistically. Further, a benchmark problem reported in the literature is solved through this model and validated through a comparison with the experimental results (beam detection due to creep and shrinkage). Under high temperature tests, H25 concrete shows better resistance for all the ranges of temperatures. This may be because of the hematite aggregate having a high melting point and strong interfacial transition zone (ITZ) properties between aggregate and cement mortar. The SCC70 shows poor performance against explosive spalling at both the ages (28 and 365 days) due to its lower permeability when exposed to high temperature. The intensity of explosive spalling is higher in SCC70 concrete tested at 28 days than at 365 days of age. This is because of variation in moisture content. SCC70 concrete failed due to explosive spalling at temperature of 398oC when tested at 28 days and failed at 575oC when tested at 365 days. This indicates the amount of moisture content in the concrete plays an important role while causing explosive spalling. F45 concrete shows a poor resistance against temperature beyond 500oC in its residual properties. SCC55 contains cement and y ash and shows higher residual properties when compared to normal vibrated M45 mix under similar high temperature conditions. Two geopolymers pastes prepared with y ash and metakaolin as a complete cement replacement were studied for passive re protection capability. The study shows MF70 mix (containing 70% y ash and 30% metakaolin) gives better resistance against heating than MF50 mix (50% each of metakaolin and y ash). Hence y ash geopolmer is a choice of material for passive re protection. An analytical model has been developed based on poromechanics to simulate high temperature e ects in concrete. Two type of spalling is considered while modelling the high temperature e ects of concrete, namely explosive and thermal spalling. Explosive spalling is estimated based on the hydro static stress (Biotech efficient times the pore pressure). If the hydrostatic stress increases beyond the tensile strength of concrete then explosive spalling occurs. Where as the thermal spalling is estimated based on the stresses developed due to applied mechanical and thermal loading. To validate this model, two benchmark problems from the literature have been solved and validated with the reported results. This model is able to predict pore pressure and temperatures gradients accurately, and this in turn helps to predict explosive and thermal spalling realistically in concrete under elevated temperature conditions.

This diploma thesis is divided into two parts, the theoretical and practical part. The theoretical part is to study of factors influencing the workability and bleeding of concrete. There is mentioned the production of cement and standard requirement. The task of the practical part is to assess the cements produced by the cement works Hranice and Prachovice. These cements test in terms of water separation. In combination with these cements use superplasticizing admixtures from Mapei and Stachema and determine the impact of water separation on cement pastes. Determine rheology on the cement pastes. Define influence of variations in cement composition affect the stability of cement mixtures.

The subject of this thesis are the rheological properties of cement paste with the addition of amorphous silicon dioxide. The basic rheological parameters are that describe the behavior of cement pastes in the fresh state. The work also included rheological tests including measurement principle and method of evaluation. Effect of mineral admixtures with high content of amorphous SiO2 is summarized the available scientific articles. In the experimental part, the effects of impurities with a high content of amorphous SiO2 on the rheological properties of fresh cement paste. It was tested by substitution of up to 10 % by weight of cement in the cement pastes mineral admixtures of different chemical composition, particle size and pozzolanic activity. Flow measurement was measured yield value, viscosity, and flow index. The stability of cement pastes was investigated oscillatory measurements. To complement the behavior pastes in the fresh state was determined by calorimetry. Test results were compared with those determined by reference samples and compared the effect of various ingredients.

Detta kandidatexamensarbete är en förstudie utfört på Cementa AB:s fabrik i Slite, Gotland, och grundar sig i att Cementa AB, Sveriges enda tillverkare av cement, står inför en omställning till helhetskonceptet Industri 4.0 som bygger på tekniker och principer för automation och digitalisering. Fabriken står även inför en hållbarhetsomställning, då branschen bidrar med stora koldioxidutsläpp genom sin tillverkning. Målet med kandidatexamensarbetet är att analyseravar Cementa AB står inför en Industri 4.0 omställning och även undersöka om det har någon koppling till deras hållbarhetsarbete. För att kunna avgöra utgångsläget för fabriken har studien konstruerat och använt sig av en mognadsmodell som bedömer vart företaget står inför en framtida omställning. Mognadsmodellen baseras på fem olika mognadsmodeller och innehåller dimensionerna Produktion, Teknik, Strategi, R&D, HR, Ledarskap, Kultur och Standardisering. Undersökningen av företagets mognad genomfördes med hjälp av en enkät, som distribuerades till fabrikens alla avdelningar. Svarsfrekvensen var på 82%. Enkätens frågor har svarsalternativ som är bedömda med poäng där lägst poäng innebär frånvaro av Industri 4.0 och högsta poäng innebär mognad inom Industri 4.0. Till varje dimensions mognad beräknades ett mognadsindex. Resultatet av enkäten analyserades med avseende på vardera dimensions avvikande mognadsobjekt för att belysa styrkor samt se potentialen inom varje dimension. Dimensionerna med lägst mognadsindex var HR och Strategi. Fabrikens totala mognad inom Industri 4.0 beräknas till nivån Existens som innebär att företaget har ett påbörjat arbete inom Industri 4.0 men saknar strategi, målbild och plan för vidare arbete. För att ytterligare belysa fabrikens möjligheter konstrueras en lista med de frågor som har störst potential. I denna lista belyses dimensionerna Strategi och Ledarskap som mest frekvent återkommande och med det anses arbetet med strategi och ledning fundamental för omställningens existens. Detta gäller även kopplingen till hållbarhetsarbetet, då ett tydligt fokus på hållbarhetsaspekterna kopplat med Industri 4.0-teknologier ger synergieffekter som hjälper varandra. Studien rekommenderar företaget i ett första skede att initiera en tvärfunktionell arbetsgrupp på ledningsnivå som har som uppgift att driva omställningen och fokuserar i ett första stadie på strategi och ledning. Sedan rekommenderar studien också att företaget i valfri ordning utvecklar enkäten för vidare uppföljning och kartläggning, jämföra sig med liknande fabriker, etablera samarbeten mellan företag, akademi och leverantörer, utforma en Roadmap för företaget och dess avdelningar samt fortsätta digitalisera verksamhetens system och strukturer. / This bachelor thesis is a case study that has been carried out at Cementa AB’s factory in Slite, Gotland, and targeted the Cementa AB’s future adaption to the concept Industry 4.0 which is based on techniques and principles for automation and digitalization. The factory is also facing a sustainability change, as the industry contributes to large carbon dioxide emissions through its manufacturing. The aim of the bachelor’s degree project is to analyze where Cementa AB is facing an Industry 4.0 transition and also to investigate whether it has any connection to their sustainability work. To be able to determine the starting position for the factory, the study has constructed and used a maturity model that assesses where the company is facing a future transition. The maturity model is based on five different maturity models and contains the dimensions Production, Technology, Strategy, R&D, HR, Leadership, Culture and Standardization. The study of the company's maturity was conducted by means of a survey, which was distributed to all the departments of the factory. The response rate was 82%. The survey's questions have response alternatives that are assessed with points where the lowest score means Absence of Industry 4.0 and highest score means Maturity within Industry 4.0. For each dimension maturity, a maturity index was calculated. The results of the survey were analyzed with respect to the different maturity objects of each dimension in order to highlight strengths and see the potential within each dimension. The dimensions with the lowest maturity index were HR and Strategy. The factory's total maturity in Industry 4.0 is calculated to the Existence level, which means that the company has started work in Industry 4.0 but lacks strategy, goals and plans for further work. To further clarify the factory's possibilities, a list of the issues with the greatest potential is constructed. In this list, the dimensions Strategy and Leadership are highlighted as the most frequent recurring, and with this the work with strategy and leadership is considered fundamental to the existence of the transition. This also applies to the link to sustainability work, as a clear focus on the sustainability aspects linked to Industry 4.0 technologies produces synergies that help each other. The study recommends the company, in a first stage, to initiate a cross-functional working group at management level which has the task of driving the transition and focuses in a first stage on strategy and management. The study also recommends that the company in any arrangements develops the survey for further follow-up and mapping, compares itself with similar factories, establishes collaborations between companies, academia and suppliers, design a roadmap for the company and its departments, and continue to digitize the company's systems and structures.

Purpose: The thesis investigated how local entrepreneurs in Slite perceive Heidelberg Materials Cement Sverige AB (HMCS) 's upcoming carbon capture storage (CCS) project—the thesis aimed to explore their perceptions of both enthusiasm and concern regarding the forthcoming mega-project in eco-innovation. Method: A case study based on qualitative research consisting of semi-structured interviews. Theory: Stakeholder Theory and Social License to Operate Results: Economic benefits such as job creation and increased local business activity are acknowledged by the entrepreneurs, who are also concerned about environmental impact, especially dust and transport-related pollution. Some entrepreneurs felt that HMCS has decreased its community involvement over time, and there is a need for increased engagement. Communication gaps were evident, and some entrepreneurs were skeptical about the project's benefits versus its potential disruptions. There was optimism about the potential, but entrepreneurs strongly emphasized the urgent need for improved corporate responsibility, better communication, and genuine community engagement. Conclusion: In conclusion, the thesis recommends that HMCS set a robust community engagement strategy for the upcoming CCS project. To achieve this, it will be essential to emphasize transparent communication, mutual feedback procedures, and community benefits such as job creation and infrastructure improvements. Creating a genuine commitment to corporate social responsibility can mitigate the concerns of entrepreneurs and foster trust between HMCS and its stakeholders.

In any developing country an increasingly higher demand for electricity supply exists. South Africa experienced load shedding during late 2007 and early 2008 and again in 2014 due to a supply shortfall. New power stations are being built to increase the capacity of the national power grid. However this is a lengthy process. Demand Side Management (DSM) was adopted by Eskom’s Integrated Demand Management (IDM) division. DSM is a short-term solution to stabilise the national grid in South Africa by managing the electricity demand on the consumer’s or client’s side. DSM aims to reduce the electricity consumption with immediate results in the short-term. DSM projects were successfully implemented at nine South African cement factories since 2012. Cement factories are ideal for the implementation of DSM projects for the following reasons: cement factories are energy intensive; have adequate reserve production capacity; sufficient storage capacity and interruptible production schedules. The aim of this study is to analyse the effect of DSM projects at South African cement factories. A detailed understanding of the cement production process is a prerequisite. Therefore a critical review of energy utilisation in the cement industry was conducted. Previous work done in the cement production field is evaluated to identify the possible literature shortfall on DSM projects. A set of five distinctive parameters was derived from the literature survey to quantify the possible effects of DSM projects at cement factories. The parameters are demand reduction and electricity cost; production targets; infrastructure; product quality and sustainability. One cement factory, Factory #1, was selected as a primary case study for the analysis model. Factory #1 was used to determine and quantify the effects of DSM projects at cement factories. A simulation was developed to verify the analysis model outcome. DSM projects were implemented at various factories in South Africa and the results from nine sites were used to validate the aim of this study. The study concluded that most DSM projects at South African cement factories were sustainable. Both the electricity supplier and the factories benefitted from the projects. The funding received from Eskom to implement DSM projects is a short-term initiative. However, sustainability of DSM projects is made possible in the long-term by the substantial electricity cost savings on the client’s or factory’s side. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

In any developing country an increasingly higher demand for electricity supply exists. South Africa experienced load shedding during late 2007 and early 2008 and again in 2014 due to a supply shortfall. New power stations are being built to increase the capacity of the national power grid. However this is a lengthy process. Demand Side Management (DSM) was adopted by Eskom’s Integrated Demand Management (IDM) division. DSM is a short-term solution to stabilise the national grid in South Africa by managing the electricity demand on the consumer’s or client’s side. DSM aims to reduce the electricity consumption with immediate results in the short-term. DSM projects were successfully implemented at nine South African cement factories since 2012. Cement factories are ideal for the implementation of DSM projects for the following reasons: cement factories are energy intensive; have adequate reserve production capacity; sufficient storage capacity and interruptible production schedules. The aim of this study is to analyse the effect of DSM projects at South African cement factories. A detailed understanding of the cement production process is a prerequisite. Therefore a critical review of energy utilisation in the cement industry was conducted. Previous work done in the cement production field is evaluated to identify the possible literature shortfall on DSM projects. A set of five distinctive parameters was derived from the literature survey to quantify the possible effects of DSM projects at cement factories. The parameters are demand reduction and electricity cost; production targets; infrastructure; product quality and sustainability. One cement factory, Factory #1, was selected as a primary case study for the analysis model. Factory #1 was used to determine and quantify the effects of DSM projects at cement factories. A simulation was developed to verify the analysis model outcome. DSM projects were implemented at various factories in South Africa and the results from nine sites were used to validate the aim of this study. The study concluded that most DSM projects at South African cement factories were sustainable. Both the electricity supplier and the factories benefitted from the projects. The funding received from Eskom to implement DSM projects is a short-term initiative. However, sustainability of DSM projects is made possible in the long-term by the substantial electricity cost savings on the client’s or factory’s side. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

The objective of this study is to provide an experimental performance assessment of cement borehole plugs subjected to dynamic loadings. This includes the study of dried-out plugs as well as of plugs that have remained wet throughout the testing period. Literature review indicates lack of quantitative data on plug performance under dynamic loading. Nevertheless, it shows that deep underground structures in competent rocks are safer than surface structures, openings at shallow depth, and openings in fractured rocks, when subjected to earthquakes and subsurface blasts. Flow test results indicate that wet cement seals are less permeable than Charcoal granite. Sealing performance is severely degraded when cement seals are allowed to dry. Dye injection tests show that the flow penetrates uniformly through the wet plugs, but occurs only along the plug/rock interface of the dried-out plugs. The permeability of wet and dried-out cement seals does not change significantly after the application of dynamic loads.

Cement Industry in Ethiopia is an emerging industry where only few pioneers were regulating the market. The complacent conditions have led them to be driven by transactional suppliers relationships, not that much customer focused, energy sources and environmental issues were not to the level required and information communications infrastructures and linkages were not that much developed. However, this oligopoly nature of the market is starting to vanish soon as a lot of national and multinational firms are appearing into the market. Accordingly, this report would identify the level of perception of organization on the general issues of supply chain management, mainly suppliers partnership, customer relationship, environmental issues and information communication; analyze their level of impacts and relationships on the competitive position of Cement Factories in Ethiopia.