In recent years, there has been a growing trend for the use of industrial by-products in the production of blended cements because of economical, environmental, ecological and diversified product quality reasons. Granulated blast furnace slag, a by-product of the transformation of iron ore into pig-iron in a blast furnace, is one of these materials which is used as a cementitious ingredient. The aim of this study is to investigate the properties of Portland slag cement (CEMII/B-S) by using separate grinding and intergrinding of granulated blast furnace slag and Portland cement clinker. For this purpose, granulated blast furnace slag was used as mineral admixture replacing 30% of the clinker. Clinker and granulated blast furnace slag were ground to four different Blaine fineness values of 3000 cm2/g, 3500 cm2/g, 4000 cm2/g and 4500 cm2/g by intergrinding and separate grinding in a laboratory ball mill. Then, eight Portland slag cement mixes and four Portland cement control mixes were prepared, in order to determine and compare 2-, 7-, 28-, and 90-day compressive and flexural strengths, normal consistencies and setting times. It was found that for the Blaine fineness values of 3000 cm2/g, 3500 cm2/g and 4000cm2/g, the 2-, 7-, 28-, and 90-day compressive strength of the interground Portland slag cements had higher values than the separately ground Portland slag cements. However, for the Blaine fineness values of 4500 cm2/g, separately ground Portland slag cement specimens had slightly higher 2-, 7-, 28-, and 90-day compressive strength values than the interground ones.

Organic soils present a difficult challenge for roadway designers and construction due to the high compressibility of the soil structure, the often associated high water table, and the high moisture content. For other soft or loose soils (inorganic soils), stabilization via cement or similar binders (a method called soil mixing) has proven to be an effective solution. To this end, the Federal Highway Administration has published a comprehensive design manual for these techniques. Organic soils, however, are not addressed therein to a level of confidence for design, as organic soils do not follow the trends of inorganic soils. This has been attributed to the high porosity, high water content, and high levels of humic acids common to organic soils. This thesis presents the findings from a literature search, laboratory bench tests, large scale laboratory tests, and concludes with recommendations for design involving soil mixing applications in highly organic soils. Laboratory tests (bench tests) were performed to assess the effect of cementitious binder type, binder content, mixing method, organic content, and curing time on strength gain. This phase involved over 500 test where in all cases, specimens with organic content higher than approximately 10% required disproportionally more cement for the same strength gain when compared to inorganic or low organic content samples. Using the findings of the bench tests, a 1/10th scale test bed was built in which soil containing approximately 44% organics was placed and conditioned with rain water. The dimensions of the bed accommodated three side-by-side tests wherein dry and wet soil mixing were performed each on one third of the bed. The remaining third of the bed was left untreated. Load tests were then performed on the three portions of the bed where the load for a simulated roadway was placed. These loads were left in place for several weeks and monitored for movement. Results showed improvement for the treated portions relative to the untreatment with virtually identical response coming from both dry and wet methods (both used identical amounts of cement per volume). The findings of this thesis suggest that the adverse effects of organic soils can be combatted where more cement content is required to bring the water / cement ratio down to acceptable levels and even more cement is required to offset the acidity. While this has been a recurring observation of past researchers, a cement factor threshold was defined by experimental data below which no strength gain was achieved. This threshold was then defined as a cement factor offset above which the measured strengths matched well with other soil types. As a result, a recommended approach for designing soil mixing applications in organic soils was developed.

Compared to the knowledge base for ordinary portland cement concrete (OPCC), relatively little information exists for calcium aluminate cement concrete (CACC), despite its existence for over 100 years. There is particularly a lack of knowledge related to early-age behavior of CACC, specifically volume change and cracking potential. To assess these early-age properties, two unique pieces of equipment were developed and employed: a rigid cracking frame and free deformation frame which enabled quantification of restrained stress generation and unrestrained autogenous deformation, respectively. These two pieces of equipment employed active temperature control and allowed a wide range of isothermal and realistic temperature conditions to be imposed upon hydrating cementitious samples. Match-cured samples (i.e. identical temperature curing to that in the frames) enabled the quantification of mechanical property development. Samples cured at discrete isothermal temperatures up to 30 °C developed tensile forces in the rigid cracking frame and exhibited shrinkage phenomena in the free deformation frame. At temperatures above 30 °C, the converse was true and significant compressive forces developed in restrained testing and expansion was observed in unrestrained testing. It was found that this was a direct result of microstructural development related to the formation of metastable phases (associated with shrinkage) and stable phases (expansion as a result of conversion from metastable to stable phases). Proper use of this material must take into account behavior associated with both types of hydrate assemblages, metastable and stable. Realistic time-temperature histories were also investigated based on field-scale concrete cast as part of this research project. It was found that volume change at earlyage was dominantly controlled by thermal history. Furthermore, it was not simply the maximum temperature reached, but the rate of temperature rise during hydration and the resulting duration of time spent at high temperature that profoundly influenced volume change and property development. The research described in this dissertation represents a significant advancement of the state-of-knowledge of this unique material and has further elucidated the role of temperature during hydration of CACC. / text

In order to test the hypothesis that fractures in outcrops are equivalent to subsurface fracture systems I compare fracture cement morphology, texture, mineralogy and geochemistry from a suite of outcrop samples from Union Springs, NY, with fractures in four cores from a currently producing reservoir in southwest Pennsylvania. Transmitted light-microscope petrography and cold cathodoluminescence of calcite of outcrop and core samples reveals a variety of cement morphologies including crack-seal and blocky fracture cement textures that are interpreted as a record multiple repeated stages of fracture opening and sealing, as well as fibrous calcite fill and other mineral phases. The stable isotopic composition of calcite fracture cements from different fracture types in cores and outcrop range from -21.5 to +4.4‰ δ13C PDB and -8.0 to -12.0 ‰ δ18O PDB and indicate calcite precipitation temperatures between 46 and 89°C. Fluid inclusion microthermometry from secondary fluid inclusions indicates trapping temperatures between 110 and 120°C. Microprobe analysis of fracture calcite cement indicates a range in Fe, Mn, and Mg composition, with subsurface and outcrop cement of similar composition. Assuming burial history predicts thermal history, isotopic compositions together with fluid inclusions suggest calcite precipitated in vertical fractures during prograde burial, during the Acadian to early Alleghanian orogenies. These findings indicate that fractures in outcrops of the Marcellus Formation can be used as a proxy for those in the subsurface. / text

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.

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The composite material of different density, where porous cement paste serves as matrix and crushed waste expanded polystyrene packages serve as inclusions, was developed. The compositions of formative mixtures and technological parameters of production for this composite material were selected and its properties were investigated. / Sukurta skirtingo tankio kompozitinė medžiaga, kurioje matrica yra poringoji cemento tešla, o intarpai - trupintos polistireninio putplasčio pakavimo taros atliekos. Parinktos minėtos kompozitinės medžiagos formavimo mišinių sudėtys, gamybos technologiniai parametrai ir ištirtos jos bandinių savybės.

Concrete, due to its low cost, durability and fire resistance, is one of the world’s most widely used construction materials. Concrete is typically reinforced with steel bars and welded wire mesh. Since the cost of steel is increasing and steel corrosion is a significant contributor to structural failure, it is advantageous to find an alternative replacement reinforcement material which can not only replace the steel, but also resist corrosion. Over the past few decades, polymeric fibres have been used as concrete reinforcement. The chemical bond between the polymeric fibre and the cementitious matrix is an important factor in the fibre’s performance as a concrete reinforcement. Despite the great importance of the chemical bonding at the polymeric fibre/concrete interface, the chemical bonding at the interface is not well understood. To investigate the chemical interactions between polymeric materials and concrete, model systems of polymeric powder/white cement and polymeric fibre/white cement were chosen, where white cement was chosen for its suitability for nuclear magnetic resonance (NMR) experiments. The chemical interactions between poly(ethylenevinyl acetate) (EVA), poly(ether imide) (PEI), and poly(vinylidene fluoride) (PVDF) polymeric powders were studied via 13C NMR spectroscopy. It was found that EVA admixture undergoes hydrolysis in a cementitious matrix and follows a pseudo-second order kinetics model up to 32 days of cement hydration. PEI was also found to undergo hydrolysis at the imide functional group in a cementitious matrix. PVDF powder undergoes dehydrofluorination in the cementitious environment, producing a brown coloured polymer which is a result of conjugation of the polymer backbone. The interfacial transition zone between fluoropolymeric powder/white cement and steel and polymeric fibres (high density polyethylene/polypropylene, poly(vinyl alcohol), PEI, PVDF, and Nylon 6.6) was studied at short range using 19F, 27Al, and 43Ca NMR spectroscopy and at long range using the scanning electron microscopy/energy dispersive spectroscopy method. It was concluded that the chemistry of polymeric fibres themselves can alter the surrounding interfacial transition zone such that the calcium silicate hydrate favours a tobermorite or jennite-like structure, which could contribute to a strong or weak interface.

It is a common observation that organizations of violence make use of moral transgression to bond new recruits to the group’s authority figures and to encourage compliance to them. The present study drew on the work of Festinger (1957), Aronson and Mills (1959) and Martens et al. (2007) and, for the first time examined this observation empirically. It was hypothesized that when participants agreed to make a moral transgression for the experimenter that they would come to view him more positively, see him as more professional and become more compliant to him, and that this would happen even more when that choice to comply was made salient. Participants were asked to place a number of bugs into a modified coffee grinder that ostensibly exterminated the bugs and then to activate the device. No bugs were killed in any condition, but participants were either led to believe that they were killing the bugs or informed that it was just a simulation. Subsequent positivity in the perception of the experimenter and how professional they considered him to be was then measured by questionnaire and compliance to him was measured in an optional data-entry task. Results yielded partial support for the research hypotheses suggesting that at least under some circumstances, agreeing to make a personal moral transgression for an authority figure leads to increases in the positivity in the perception of that figure and compliance to him and that making that choice salient enhances this effect. The implications of this finding for the understanding of the processes by which a person can become bonded to unsavory authority-figures and potential applications to community education programs are discussed; as are the limitations of this study and possibilities for future research.

In order to be sustainable, companies have to adapt in the ever–changing market and economic conditions which are often unpredictable. The adaptation to these challenges rests with employees who have to stay motivated and psychologically well. The environmental working conditions are often undesirable The objective of this study was to evaluate the psychometric performance of the Utrecht Work Engagement Scale (UWES) and the Oldenburg Burnout inventory (OLBI) within the cement factory. A random sampling approach was adopted by distributing a questionnaire for the purposes of achieving the general research objective with an availability sample (N = 187). The UWES and OLBI were administered. Exploratory factor analysis, descriptive statistics, Cronbach alpha coefficients, Pearson product–moment correlations and MANOVA's were used to analyse the data. The outcome of the study through literature review confirmed that work engagement and burnout are two important components of employee wellbeing. The factor loadings of the UWES and OLBI resulted in a two–factor structure for both the UWES and OLBI. The two factor structure for the UWES were labelled as Vigour/Dedication and Absorption. The twofactor structure for the OLBI was labelled Disengagement and Exhaustion. A small number of items were retained for the OLBI. The internal consistency of the UWES was found to be well above the acceptable level with the alpha coefficients exceeding 0,70. The internal consistency for the OLBI was found to be lower than the 0,70 level. Data analysis further showed that correlations between engagement and burnout were statistically insignificant. Data analysis also showed that there were no vi significant differences for age and gender for both engagement and burnout, however there is a significant difference in race and language with regard to engagement but none for burnout. Limitations within the study were identified and recommendations for future research were made. / Thesis (M.A. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2011.