A feasibility of rapid setting cement (RSC) as an agent of immobilization for certain elements such as fission products or radioactive materials was explored. Cerium (Ce) and cesium (Cs) have been selected as a surrogate for U and/or Pu and fission products, respectively, in this study in three phases. In Phase I, RSC was evaluated for physical properties (e.g., porosity, density, pH values, etc.) using two groups methods—the cement powder at different concentrations of Ce (2 – 10 wt%) with deionized water (DIW) and artificial seawater (ASW). The results showed that the final setting time and compressive strength of RSC in DIW and ASW solutions decreased as Ce content increased. The X-ray diffraction patterns revealed two newly identified phases, namely CeAl11O18 and Ce4.667 (SiO4)3O. The morphology of matrix samples showed that the existence of Ce distributed on the pore wall or clustered with Si, Al, Mg, K, P, Fe, and O. In Phase II, laser-induced breakdown spectroscopy (LIBS) technique together with univariate and multivariate analyses of the principal component analysis (PCA) and partial least squares (PLS) were applied to detect the surrogate elements (Ce (0.5 – 8 wt%) and Cs (0.5 – 4 wt%)) for nuclear materials captured in ceramic materials. The best calibration curves for Ce and Cs in samples were created using the peak areas of the Ce 571.8 nm line and Cs 697.1 nm line, respectively. PCA method was applied to explain 85.5 % for Ce-cement samples in DIW and 91.4 % for those in ASW. Samples with Cs indicated similar PCA trends. The PLS calibration curves for Ce and Cs samples in DIW and those in ASW were made using seven and eight latent variables (LV). In Phase III, the leaching behaviors of Ce and Cs mixture with DIW and ASW under both dynamic and static leach conditions were investigated according to the ANSI/ANS 16.1-2003 standard method. Elemental compositions were analyzed using an inductively coupled plasma-mass spectrometry (ICP-MS) for the leaching periods of 2, 7, and 24 hours and 2, 3, 4, 5, 14, 28, 43, and 90 days. Three mathematical models—first-order reaction model (FRM), diffusion model (DM), and first-order reaction/diffusion model (FRDM)—were fitted to assess the leaching parameters of immobilized radionuclides in the RSC matrix. Results showed that leaching of 140Ce and 133Cs from RSC matrices with (DIW and ASW) under both dynamic and static leach conditions was less than 20%. It was found that the leaching phenomena of 140Ce and 133Cs was dominantly controlled by FRM with a weak effect of DM, which was best fitted by FRDM. Here, the average leachability index (L) for 140Ce and 133Cs, are greater than the recommended minimum of 6 that allowed their acceptance for disposal. These studies indicated a good feasibility of using RSC with DIW and ASW for immobilizing non-radioactive Ce and Cs and RSC had a potential for applying to actual radioactive materials.

In the process of crushing concrete waste, significant amounts of fine by-products, the so called fine recycled concrete aggregates (FRCA), are generated and excluded from potential use. Limited research has thoroughly investigated the performance of concrete mixes with FRCA, very likely due to the complexity in analysing non-negligible amounts of adhered residual cement paste (RCP). Although some studies have proposed promising sustainable mix-design procedures accounting for the different microstructure when using coarse recycled concrete aggregates (CRCA), no similar approach exists for FRCA concrete. In this work, two promising procedures for mix-designing eco-efficient concrete with 100% FRCA are proposed accounting for the presence of RCP to reduce cement content in new mixtures. First, built on top of the existing procedure for CRCA mix-design, modifications to the Equivalent Volume (EV) method were introduced toconsider full replacement of fine natural sand by FRCA. Second, based on the concept of continuous Particle Packing Models (PPM), an optimized procedure was proposed to allow maximum packing density of FRCA mix linked to a given level of measured RCP content. Results verified the feasibility of producing eco-efficient concrete mixes with 100% FRCA, emphasizing the PPM mixes to report superior rheological and mechanical performance along with suitable durability-related properties. Yet, results also indicated the influence of simple or multistage crushed FRCA on the overall performance of mixes.

Este trabalho realizou o estudo do comportamento de misturas de solo arenoso e argila, estabilizado quimicamente com cimento, para aplicação em barreiras de proteção ambiental. A proposta essencial foi a utilização de um solo arenoso, proveniente da Formação Botucatu, presente em vastas áreas do território brasileiro e através de um processo de alteração, torná-lo apto à utilização em barreiras de proteção ambiental. O projeto e análise de experimentos foram realizados através da técnica de planejamento fatorial 23 composto. Foram consideradas três variáveis independentes: teor de umidade (w), porcentagem de cimento (C) e quantidade de argila (A), variando em dois níveis cada. Foi utilizado cimento Portland CP II-Z 32 e argila bentonita sódica comercial. Foram avaliados os comportamentos de fluxo e transporte de água e contamintante (KCl), realizados através de ensaios de percolação em coluna e com permeâmetros de parede rígida com carga constante e ensaios de equilíbrio em lote. Foram avaliados os parâmetros de resistência do solo com os ensaios de resistência à compressão simples (RCS) e cisalhamento direto (CD). Também foram avaliados os comportamentos de expansão e contração das misturas. Foram realizados ensaios de porosimetria por intrusão de mercúrio para verificar a alteração microestrutural das misturas. Após realização dos ensaios, as analises estatísticas permitiram avaliar os efeitos das variáveis independentes sobre as propriedades das misturas. Os fatores w, C e A se mostraram adequados para descrever o comportamento das propriedades avaliadas das misturas. Os parâmetros de fluxo e transporte se mostraram adequados para a finalidade do material. As misturas solo-cimento-argila apresentaram ganho elevado de resistência e comportamento mais estável frente a contração quando comparadas as misturas solo-argila. Foi empregado o método de superfície de respostas para interpretar o comportamento e identificar a tendência de alteração das propriedades. Com o procedimento proposto foi possível avaliar a influência dos fatores e descrever as alterações causadas pelas misturas com cimento e argila. / In this research the behavior of sandy soil and clay mixtures, chemically stabilized with cement, for application in environmental protection barriers was determined. The essential proposal was to use of a sandy soil, from Botucatu Formation, present in vast areas of the Brazilian territory and through an alteration process, make it suitable for use in environmental protection barriers. The design and analysis of experiments were performed using the 23 factorial composite technique. Three independent variables were considered: moisture content (w), percentage of cement (C) and amount of clay (A), varying in two levels each. Portland cement CP II-Z 32 and commercial sodium bentonite clay were used. Flow and transport behavior of water and contaminant (KCl) were evaluated through column percolation tests and with rigid wall permeameters with constant load and batch equilibrium tests. The soil resistance parameters were tested with the simple compression strength (RCS) and direct shear test (CD). The expansion and contraction behavior of the mixtures were also evaluated. Mercury intrusion porosimetry tests were performed to verify the microstructural alteration of the mixtures. After the statistical analysis, it was possible to evaluate the effects of the independent variables on the properties of the mixtures. The moisture, cement and clay contents were adequate to describe the behavior of the evaluated properties of the mixtures. The flow and transport parameters were adequate for the purpose of the material. The soil-cement-clay mixtures presented a high gain of resistance and a more stable behavior against contraction when compared to soil-clay mixtures. The response surface method was used to interpret the behavior and to identify the tendency of the properties. With the proposed procedure it was possible to evaluate the influence of the factors and to describe the changes caused by the mixtures with cement and clay.

Doctor of Philosophy(PhD) / Soil Stiffness is an important parameter for any geotechnical engineering design. In laboratory tests it can be derived from stress-strain curves or from dynamic measurement based on wave propagation theory. The second method is a more accurate and direct method for measuring stiffness at very small strains. Until now dynamic measurements have usually been obtained manually from the triaxial test. Attempts have been made to automate the procedure but have apparently failed due to the high level of variability in dynamic measurements. Moreover, triaxial tests of soil can be very lengthy and manual dynamic measurements can be very tedious and impractical for long stress-path tests. In this research a computer program has been developed to automate the stiffness measurement (using bender elements) based on the cross- correlation technique. In this method the program records all the peaks and corresponding arrival times in the cross-correlation signal during the test. The stiffness is calculated and displayed on the screen continuously. The Bender Element enabled to get the small strain shear modulus. An arbitrary “Chirp” waveform of 4 kHz frequency was used for this purpose. Subsequently Bender Element test results were checked by ‘Sine’ waveforms of frequencies 5kHz to 20kHz, as well as by manual inspection of the arrival time. This thesis discusses the method and some of the difficulties in truly automating the process. Finally some results from a number of stress path tests on uncemented and cemented calcareous sediments are presented. Bender elements have been used by many researchers to determine the shear modulus at small strain. Most previous studies have used visual observation of arrival time, which is time consuming and often requires some judgement from the operator. This thesis will describe the use of cross-correlation as a method for automation of Gmax measurement. Cross-correlation has been claimed to be unreliable in the past. However, it will be shown that provided several peaks in the cross-correlation signal are monitored it is possible to follow the variation of Gmax throughout consolidation and shearing. The measurement can be made at regular intervals within the software controlling a stress-path apparatus. Details of the apparatus used and practical considerations including selection of waveform and frequency are discussed. A series of drained cyclic triaxial tests was carried out on artificially cemented and uncemented calcareous soil of dry unit weights 13, 15, and 17 kN/m3 and sheared with constant effective confining stress 300 kPa. Gypsum cement contents of 10%, 20% and 30% of the dry soil weight were used. In addition a series of stress path tests were performed on Toyuora sand samples. Results will be presented for two uncemented and one cemented sand. In addition to the bender elements, all tests had internal instrumentation to monitor axial and lateral strains. Results will be presented for Toyura sand to show that the measurements are consistent with those obtained by other methods. Results will also be presented for carbonate sand subjected to a wide range of stress paths. Finally, results will be presented for the carbonate sand cemented with gypsum. The degradation of Gmax of the cemented soil subjected to variety of monotonic and cyclic stress-paths is presented. Analysis of the results includes assessment of the factors influencing Gmax for uncemented sand. Preliminary analysis indicates that in order of importance these are the mean effective stress, the stress history, void ratio and stress ratio. For cemented sand, Gmax is initially constant and independent of stress path. After yielding the modulus degrades, becoming increasingly stress level dependent and eventually approaches the value for uncemented sand. Factors influencing the rate of degradation are discussed. For the Toyuora sand samples the effects of end restraint on the stress-strain response at small strains were investigated. The conventional method of mounting triaxial specimen has the effect of introducing friction between sample and end platen during a compression test. This inevitably restricts free lateral movement of the specimen ends. Frictional restraint at the sample ends causes the formation of 'dead zones' adjacent to the platens, resulting in non-uniform distribution of stress and strain (and of pore pressure if undrained). On the other hand the specimen with 'free' ends maintain an approximate cylindrical shape instead of barrelling when subjected to compression, resulting in a more uniform stress distribution.

In the Permian Basin, strata of Leonardian age typically consist of interbedded carbonates and siliciclastics interpreted to be turbidite deposits. Happy Spraberry Field produces from a 100-foot thick carbonate section in the Lower Clear Fork Formation (Lower Leonardian) on the Eastern Shelf of the Midland Basin. Reservoir facies include oolitic- to-skeletal grainstones and packstones, rudstones and in situ Tubiphytes bindstones. Depositional environments vary from open marine reefs to shallow marine oolitic shoal mounds. Best reservoir rocks are found in the oolitic-skeletal packstones. Diagenesis occurred in several phases and includes (1) micritization, (2) stabilization of skeletal fragments, (3) recrystallization of lime mud, (4) intense and selective dissolution, (5) precipitation of four different stages of calcite cement, (6) mechanical compaction, (7) late formation of anhydrite and (8) saddle dolomite and (9) replacement by chalcedony. Oomoldic porosity is the dominant pore type in oolitic grainstones and packstones. Incomplete dissolution of some ooids left ring-shaped structures that indicate ooids were originally bi-mineralic. Bacterial sulfate reduction is suggested by the presence of (1) dissolved anhydrite, (2) saddle dolomite, (3) late-stage coarse-calcite cement and (4) small clusters of pyrite. Diagenetic overprinting on depositional porosity is clearly evident in all reservoir facies and is especially important in the less-cemented parts of the oolitic grainstones where partially-dissolved ooids were subjected to mechanical compaction resulting in "eggshell" remnants. Pore filling by late anhydrite is most extensive in zones where dissolution and compaction were intense. Finally, a porosity-permeability model was constructed to present variations in oolitic packstone- rudstone-bindstone reservoir rocks. The poroperm model could not be applied to oolitic grainstone intervals because no consistent trends in the spatial distribution of porosity and permeability were identified. Routine core analysis did not produce any reliable value of water saturation (Sw). An attempt to take advantage of wireline log data indicates that the saturation exponent (n) may be variable in this reservoir.

A considerable amount of waste is obtained as a result of edge-cutting operations during cement-bonded wood particle board (CBWPB) manufacturing. This waste material which basically contains wood chips and hydrated cement has to be disposed of and does not have any economical value. However, it can be burned in cement rotary kilns and may result in energy savings to a certain extent due to the presence of wood particles as a secondary fuel and since the hydrated cement may be decomposed and then reform clinker compounds during the calcination process. In this experimental study, the possibility of using waste CBWPB in cement manufacturing and its effects on energy consumption and cement characteristics will be investigated. The reference mix, corrective limestone, CBWPB waste and coal, were used as raw materials to prepare six different raw meals whose chemical compositions was similar to reference mix. All six raw mixes (including the reference) were calcined under the same conditions to produce clinkers. The compositions and micro structure of the clinkers obtained were comparatively analyzed by wet analysis, XRF and XRD techniques. Cements were obtained by intergrinding the clinkers with 5% (by mass) gypsum rock and standard tests were carried out on each of the cements. In addition to these, since CBWPB waste contains wood about 30% by weight, its contribution to fuel consumption during clinker production was also analyzed. The test results revealed that CBWPB waste can be used as a cement raw material since CBWPB waste has the similar chemical composition with the reference raw mix. CBWPB, which contains about 30% (by mass) wood, contributes to the heating process during calcination and results in lower amount of primary fuel requirement.

This thesis, comprising 5 separate studies, is concerned with fixation of prosthetic components in total hip arthroplasty. The results and conclusions of the studies fol-low; The initial stability of femoral revision components, the long cementless PCA stem and the Exeter standard stem cemented in a bed of impacted bone graft, was com-pared in an experimental study. The PCA stem was more stable than the Exeter stem. However, for both stems initial stability may not be sufficient to allow bone ingrowth. Initial fixation is especially vulnerable to torsion. Identical femoral stems with or without HA-coating were compared in a prospec-tive randomized clinical trial. The long-term stable fixation of a cementless Link RS femoral component was improved by application of hydroxyapatite coating to the femoral stem. In a clinical study the method of extensive impaction of morsellized bone allograft and a hydroxyapatite-coated cementless Mallory-Head acetabular component was found to be advantageous for acetabular revision in the presence of contained or acetabular wall defects. The limited contact between the HA-coated implant and living host bone did not seem to compromise long-term stable fixation. Two different cup designs were compared in a prospective randomized RSA study. At 3 years after implantation the cemented low profile Lubinus FAL cup performed as well as the cemented Lubinus Standard cup in terms of migration and polyethyl-ene wear. In a study of the relationship between radiolucent lines and migration the Lubinus FAL cup displayed more radiolucent lines in the cement bone interface than the Lubinus Standard cup but no difference in migration was found. Early appearance of such radiolucent lines represents an unspecific finding without reliable correla-tion to 3-year migration of the acetabular component.

The objective of this thesis is to investigate the photocatalytic activity in nanosized TiO2 structures. Two different structures were used for two different reaction systems. In the first part of the study, TiO2 coated on glass beads by a sol-gel procedure were used to test the photocatalytic CO2 reduction reaction with H2O and H2 in the gas phase. The results of photocatalytic CO2 reduction reaction revealed that CO2 reduction step of the overall reaction proceeds in dark / while illumination is required for water splitting reaction. In the second part of the study, Photocatalytic oxidation activity of the commercial TiO2 powders mixed with grout and plaster were studied for a potential commercial self cleaning material. A method based on gas phase benzene oxidation was developed for testing TiO2 added cement based self cleaning surfaces. This method was used to screen 15 commercial TiO2 samples with and without cement. Based on this method a commercial TiO2 sample (S9) was selected for further use. Surface of 15 commercial TiO2 samples were characterized by using NO and CO2 as probe molecules. Photocatalytic benzene oxidation experiments showed that using TiO2 on the surface lead to more effective surfaces in terms of photocatalytic activity. TiO2 was bound to surface by inorganic materials without much activity loss. This kind of amount optimization is of commercial importance.

The complex interaction between cement and chemical/mineral admixtures in concrete mixtures sometimes leads to unpredictable concrete performance in the field which is generally defined as concrete incompatibilities. Cement paste rheology measurements instead of traditional workability tests (i.e., slump cone test) can have great potential in detecting those incompatibilities in concrete before the concrete is placed, which can, in turn, avoid related workability problems and setting time as well as heat evolution abnormalities. The objectives of the present study were to examine the applicability of the dynamic shear rheometer (DSR) to measure cement paste rheology, and to identify cement and mineral/chemical admixture incompatibilities, based on the determined rheological parameters. The DSR was modified and optimized for cement paste rheology measurements. Two different modes of operations (i.e., static and dynamic methods) with the modified DSR were investigated to measure representative rheological parameters as well as to identify cement and chemical/mineral admixture incompatibility. The conventional plastic viscosity and yield stress are measured in static mode and storage modulus curve, as a function of time, is measured in dynamic mode. The rate of change of plastic viscosity (RPV) as another static rheological parameter and the modeled magnitude parameter ?, from the dynamic rheological method, showed great potentialities as acceptance criteria to identify incompatible mixtures. The heat of hydration data from isothermal conduction calorimeter tests and setting time results for the studied mixtures have strongly supported the rheology based observations as supporting tools. Based on the main tests results, the acceptance criteria were set up using the rheological parameters in accordance with heat of hydration data. This will ultimately help material suppliers, concrete producers, and other users to detect problematic combinations of concrete ingredients before a given concrete mixture is placed.

Examined in this study were some physical, mechanical, compositional and durability properties of AAC, its neighboring plasters and jointing adhesive, all of which were produced in Turkey. The compatibility of these materials inside the contemporary wall section and within historic fabric was discussed in terms of their material properties. In addition to the literature survey, laboratory studies were conducted on two types of AAC as G2 and G4, its jointing adhesive and exterior finishing layers as base coat, under coat, finish coat, water repellent finish coat / and some historical traditional construction materials of Anatolia as timber, masonry and infill brick, lime based exterior and interior plasters. The results were evaluated in terms of material properties of AAC, the compatibility of AAC and its complementary elements with each other and with the historic timber framed structures in Anatolia. It was concluded that the use of AAC in repairs of historical structures could be discussed only if the original infill is lost. In addition, its cement-plasters should be avoided from the historic fabric since they introduce salt problems to the structure. In terms of vapor permeability and modulus of elasticity, water repellent finish coat was proper finishing for AAC, and AAC, especially G4, exhibited similarities with historic infill mud brick. Further studies on other compatibility parameters were, however, necessary to decide on the compatibility of AAC with its neighboring materials. Moreover, the integrity of AAC with the historic fabric needed improvement by increasing its pozzolanicity and/or producing a new intermediary repair mortar/plaster.