The deterioration of the surfaces of the constructions made with mortar C/A 1: 5 of Portland cement, are produced by being exposed to the emission of toxic gases emanating from the growing automobile fleet, this problem causes alternatives to be sought in order to counteract its effect on buildings and the environment. A new method to deal this problem is the incorporation of the titanium dioxide photocatalyst (TiO2) into the Portland cement mortar, which can develop self-cleaning and air purification properties to be in contact with sunlight. This work seeks to introduce this organic component to the Portland cement mortar, used for the facade charging and structural elements, for this purpose, different percentages (5%, 7.5% and 10%) of titanium dioxide (TiO2) are added and the properties of the modified mortars making use of [1] compression tests, [2] fluidity tests, [3] absorption tests and [4] photocatalytic activity tests with which the self-cleaning capacity was verified. This study concludes that the best percentage of titanium dioxide addition is 5%, with which the Portland cement mortar is granted self-cleaning property without substantially damaging its mechanical properties.

Abstract  Aim: To determine the shear bond strength of two commercially available self-adhesive resin cements on four different materials and to analyse the degree of conversion (DC) of those resin cements.  Materials and Methods: A total of 45 embedded specimens made of four different materials were prepared for the notched-edge shear bond strength test. Ten specimens each of resin composite, glass-ionomer, zirconia and 15 of human dentine. Pillars of two different self-adhesive resin cements were luted onto these specimens. Five of the dentine specimens were treated with Katana Cleaner before being luted with Panavia. A single sample from each self-adhesive resin cement was used to determine the DC using ATR-FTIR Spectroscopy. The samples were measured uncured, right after being light cured and 10 min thereafter. Results: The highest shear bond strength values were seen for RelyX, irrespective of the material tested. This difference was statistically significant. No statistically significant difference was seen between the dentine specimens pre-treated with Katana Cleaner and luted with Panavia, compared to no pre-treatment. No statistically significant differences were found regarding DC between Panavia and RelyX.  Conclusion: The bond between the dental materials and the tooth structure is extremely important for the longevity of the restoration. The bond strength of RelyX for all materials tested were 2.1 to 37.5 times higher than that for Panavia and the differences were statistically significant. Panavia had virtually no bonding to the dentine in this study which might be due to the treatment of the dentine. The differences regarding the degree of conversion between the two resin cements were not statistically significant. However, the DC 10 min after curing was 1.3 times higher than directly after curing for both resins.

In the theoretical part, I mentioned the project management of buildings and the construction of prices in construction. In the next section I have described the building site and its water supply requirements. Finally, I have dealt with the cost of water and its consumption. The aim of the thesis was to analyze the influence of water prices on the cost of construction. I transferred this analysis to the model building in the practical part of the thesis. I determined the water consumption during construction, and then I analyzed the impact of the change in water prices on the construction cost.

In this study, the freeze-thaw performance and other engineering properties of different cementitious mixtures containing Type I/II portland cement, Type IL (10) portland Limestone cement (PLC) and Coarse Ground cement (CG-P) with or without partial replacement of fly ash (Class F) were examined. The goal was to develop a concrete mixture with better or similar freeze-thaw durability without adversely affecting other engineering properties of concrete. Crucial engineering properties reviewed include compressive strength, splitting tensile strength, workability, the degree of hydration, setting time, shrinkage and resistivity. The study was divided into two parts, one consisting of mechanical testing of engineering properties including the freeze-thaw test. The second part consisted of microstructure study which involved detection and quantification of micro-cracks/defects using μ-CT and fluorescence microscopy. The results showed that the portland limestone cement in combination with fly ash demonstrated better or similar durability in comparison to the conventional portland cement concrete mixtures.

The subject of the diploma thesis is the study of moisture resistance of macrodefect-free (MDF) cements based on calcium-aluminate cement and polyvinylalcohol used as polymer. MDF cements are perspective materials providing unique properties relative to traditional cement pastes with great potential to incoming constructional utilization. But it is known that MDF cements exhibit sensitivity to water, with swelling and reduction of strength. Therefore the work is aimed in monitoring of an organic polymer effect on the moisture resistance of MDF materials and phase changes. Aluminate cement (SECAR 51) and polyvinylalcohol/acetate copolymer have been used for the MDF cement preparation. The moisture resistance of model MDF cement samples was investigated at two different curing conditions: in the moist atmosphere and immersed in water. The influence of composition and individual curing on the properties of model MDF cement samples was observed. The characterization of MDF samples was based especially on test of flexural strength, FT-IR, EDAX and optical microscopy analyses.

This thesis explores the posibility of using of foundry filter ash for production of inorganic composite materials, that could be used primary in the construction industry. The thesis is divided into theoretical and experimental section, where theoretical section contain literature review of used materials and the experimental section summarizes the results of laboratory tests performed on tested mixture based on portland and alumina cement with various content of foundry filter ash. For comparison was also used another foundry waste - foundry sand. Prepared test bodies with dimension of 40 x 40x 160 mm was subjected to mechanical strength tests and the influence of amount of foundry waste on the strenght of the prepared mixtures was monitored. Next the thesis deals with possibilities of alkaline activation of foundry waste, where sodium water glass, sodium hydroxide and commercially supplied baucis L 160 component B were used as alkaline activator. These test mixtures were also subjected to mechanical strenght tests and the influence of amount of foundry waste on the strenght was observed too. The analysis of input materials were performed by XRF, TG – DTA – EGA and XRD powder diffraction methods. All strength tests were tested by testing equipment desttest 4310.

In theory, this work is devoted to the principles and methods of measurement of volume changes of mortars and concretes. Emphasis is placed on cement self-levelling screeds with initial shrinkage compensation. In the practical part of the work is devoted to the development of prototype measuring system designed for non-contact detection of volume changes hydrating silicate. Using the new measurement method is also practically examined the influence of boundary conditions on hydration volume changes of selected silicate binders, cement mortar and cement levelling compound based on four different connective concepts. In the calculation, this work focuses on the numerical modelling of volume changes of the examined compounds.

The thesis deals with possibilities of FBC fly ash utilization for composite cements. It focuses on thermodynamic stability of ettringite, which is produced during composite cements hydration. Specific tasks are dedicated to observation of influence of outdoor environment and influence of calciumhydrosilicate environment to stability of ettringite.

This report presents the results of analyzing the critical void ratio concept on weakly cemented sand. The study consists of drained triaxial compression tests performed on artificially cemented sands created to simulate the natural behavior. In order to carry out this study, loose samples were prepared and subjected to different confining pressures such that failure at volumetric contraction could be obtained. The triaxial test results showed that the samples exhibited similar response to drained loading as compared to previous investigations on the static behavior of naturally and artificially cemented sands. Following the empirical method of determining the critical void ratio by plotting volumetric strain at failure against void ratio after consolidation, interpolation of the data points yielded critical void ratios of 0.735, 0.722, 0.703 and 0.668 for confining pressures of 60, 70, 80 and 95, respectively. A comparative analysis was made by plotting instantaneous void ratio during the loading against axial strain and this yielded values of 0.745, 0.735, 0.715 and 0.685 for confining pressures of 60, 70, 80 and 95 respectively. However, this method depends on the test accuracies at strain levels beyond 20% where the specimen becomes severely distorted, thus, making this method unreliable to use. Utilizing the result from volumetric strain-void ratio curves, the relationship between volumetric strain at failure and confining pressure was plotted and yielded critical confining pressures of 125, 94, 78, 67 and 60 psi for void ratios after consolidation of 0.66, 0.68, 0.70, 0.72 and 0.74, respectively. From the above results, the critical state line, which shows the variation of the critical void ratio, e_crit with the magnitude of the cr1 critical confining pressure, σ₃_crit, was defined for the artificially prepared samples with one percent cement. It would be interesting to compare this result with the critical state line of uncemented samples and of samples with higher amounts of cementation. The critical state concept is very important in evaluating the undrained strength of sands from drained tests data. The reader is referred to reference 7 since this is beyond the scope of this investigation. This concept is also an important study used in determining the liquefaction potential of sands. A paper by Castro [2] reported that liquefaction can only occur in sands that are looser than the critical state. The results of consolidated-undrained static tests will indicate whether the sand is looser or denser than the critical void ratio for the appropriate confining pressure, and thus whether the sand is susceptible to liquefaction. The reliability of the parameters obtained depends on a very limited number of data points. The author suggests that more tests on a wic!er range of relative density and confining pressure should be conducted to obtain more data points where a more accurate interpolation or extrapolation could be done. However, the results presented in this report are hoped to provide useful information for further studies to be made on the analysis of critical void ratio concept in cemented sands. / Master of Engineering

Ground improvement by deep mixing (DM) is a generic term used for a number of methods in which a binding agent, often lime and/or cement, is mechanically mixed with the soil to increase its engineering properties. The inherent variability with respect to the engineering properties of the improved soil is high due to the variations in geology and the complex mixing process. High variability introduces uncertainty in estimating improved soil properties and the performance of the structure. Current design methodology deals with soil properties deterministically and the uncertainties involved are incorporated in a single value represented by a total factor of safety (FS). The chosen FS is highly dependent on the engineer’s judgment and past experience, in which both of these factors vary between different geotechnical designers. Therefore, current design methodology used in practice for DM does not deal with uncertainties in a rational way. In order to design a geotechnical system with the desired level of confidence, the uncertainties involved must be integrated in the DM design. This can be achieved by using reliability-based design (RBD) methods. The research work in this thesis is presented as a collection of three papers. In the first paper, a comprehensive statistical analysis of cone penetration test (CPT) data is described. The objective was to make a contribution to empirical knowledge by evaluating the strength variability of lime-cement columns within the group of tested columns. In the second paper, the effect of the spatial variability and statistical uncertainty with regard to the embankment’s reliability was investigated within the framework of RBD. The study in the third paper investigated the strength variability in lime-cement columns based on two test methods, namely CPT and column penetration test (KPS). In this study, the effect of different test methods on the evaluation of the design value was addressed. The main conclusions from this study can be summarized as follows. First, the probability distribution function (PDF) for the undrained shear strength of lime-cement columns can be modeled in RBD as normal or log-normal distributions. However, the use of log-normal distribution is recommended for RBD analyses. Second, the evaluated scales of fluctuation indicate ranges of 2 to 4 m and 0.2 to 0.8 m in the horizontal and the vertical directions respectively. This means that in order to fulfill the requirements of independent/uncorrelated samples for assessment of the design value, the spacing between samples must exceed the horizontal scale of fluctuation. It is therefore proposed that the spacing between individual samples should be at least 4 meters. Third, the design values evaluated using CPT and KPS were approximately the same. However, the inherent variability evaluated differs due to the larger volume tested with the KPS probe than with the CPT probe. However, this difference was not significant between the two tests. Fourthly, due to the limitation in the deterministic design in terms of dealing with uncertainties, it is recommended that RBD design should be used in parallel with the deterministic design of lime-cement column. / <p>QC 20120110</p>