In line with the current focus on utilizing side products of various production processes, this dissertation thesis analyzes the process of alkali activation of particular side products: fly ash and brick fragments. This activation produces geopolymeric materials widely used in civil engineering. The thesis aims to optimize the geopolymerization process so that the resulting geopolymer is both ecologically and economically viable. To that end, the thesis studies the course of geopolymeric reaction between the alkali activator and fly ash from: (i) the Chvaletice power plant, (ii) the Dětmarovice power plant, and (iii) biomass combustion, as well as (iv) fluid fly ash from the Hodonín power plant. All experiments of geopolymeric reaction have focused on the factors influencing the synthesis of geopolymers—that is: composition of the alkali activator, the ratio of alumino-silicate to the activator, and the impact of temperature on structure of the synthesized geopolymer. Further, the thesis analyzed the synthesized polymer’s microstructure, phase composition, resistance against corrosive conditions, and compressive strength, as well as mechanical-fracture properties of selected fly-ash geopolymers. The thesis finds that the most suitable for geopolymeric synthesis appears to be the fly ash from the Chvaletice power plant in which case the obtained geopolymers showed best properties in the studied areas. The fly ash from the Dětmarovice power plant, biomass fly ash, and fluid fly ash have failed to reach acceptable properties. Separately, the thesis studies the geopolymerization of brick body that could be suitable input for alkali activation. The geopolymers synthesized from brick fragments resulted in materials of supperior mechanical strength. A mixed use of fly ash and brick fragments failed to show a synergetic effect. Properties of the resulting geopolymers have been inferior to the properties of geopolymers produced using just fly ash or just brick body.

This diploma thesis is focused on composition and processing of cellulose fibers and their usage in cementitious composites. It describes key attributes of cellulose fibers, which has to be acquired for effective use in cement composites. There are stated effects of cellulose fibers on concrete properties, such as workability, physical and mechanic attributes and freeze-thaw resistance. In experimental part is designed a mixture with portion of cellulose fibers. There has been performed various tests to define the effect of cellulose fibers. There was designed experiment to determine its alkali resistance for fibers itself, and possible changes in microstructure of fibers were analyzed by optic and electron scanning microscope.

Work describes the relationship between structure and mechanical properties in case of hybrid mixtures. They are composed from polyurethane matrices (eventually polyurethane-urea or polyurethane-inorganic filler mixtures), different rubber fractions as filler and eventually reinforcement made from PET monofilaments. Mechanical behaviour was studied by tensile testing. Studied mechanical properties include tensile modulus, ultimate strength and strain and also specific energy need neccessary for ultimate strength achievement. Prepared materials are naturally porous. Therefore their mechanical behaviour has to be described generally for porous composites. The porosity occurence means, that it is difficult to describe them by models valid for mechanical behaviour (mainly elastic modulus) of nonporous composites. Models are also based on idealized structures on microscopic level. In case of porous composites, it is very difficult to create any idealized structure. The structure is changed with modifications of composition (change of components or their rates). These conditions have lead to utilizing of different approach how to describe the relationship between structure and mentioned mechanical properties. The chosen approach comes from knewledge about structural parametres coming from porosity. Structural parameters describe the structure on macroscopic level. They include interspace volume (volume lying between filler particles), interspace filling (how the matrix fills the interspace volume) and matrix volume fraction. Proposed parameters are used in relations, where they are fitted by exponents to interlay values of chosen mechanical properties for composites containing discrete matrix and filler. Found exponents are then described by properties of matrices to obtain relations describing properties of filled porous materials. Very similar approach was chosen for description in the case of reinforced composites. Proposed relation are potentially valid for materials containing binding matrix, infinity count of fillers and one kind of reinforcement.

The works deals with the possibilities of using non-standard fraction of fine crushed aggregate in route base layers. Goal of my thesis is research of using material from specific location. Theoretical part summarizes basic knowledge regarding bound mixtures and their normative requirements. Practical part of my thesis describes my various mixture design and following testing and determination of design properties by official and experimental tests. The conclusion summarizes the researched outputs and findings, which confirm the future possibilities of using this material in base layers.

This diploma thesis is divided into two parts, theoretical and practical. The is a review om the topic of recycled asphalt pavement and recycled concrete and their possible use in road construction in the theoretical part. The individual chapters deal with describing these materials, their production, and their use in construction layers of pavements. In the next chapters the attention is also paid to their problematic features and foreign experience using these materials in pavements. In the practical part, laboratory samples of recycled asphalt pavement and recycled concrete and their mixtures with cement are tested. The main purpose is to verify the applications of these mixtures of recycled asphalt pavement and recycled concrete in the bonded base layers of the pavement. Another purpose is to compare how these mixtures individual properties with different proportions of both components and different amounts of cement will be different. In the end, the two mixtures with the best properties was selected and the modulus of elasticity was experimentally determined for the possibility of replacing the currently used base layers and the economic evaluation of this design was made.

The influence of seven additives on the crystallization ability of polylactide (PLA), melt flow index (MVR) and mechanical tensile properties was studied. Pressed plates with a thickness of 0.8 mm were tested. Selected additives added in amounts of 0.5 and 1.0% were as follows: talc, sodium benzoate, mixtures of organic salts with amorphous SiO2 and zinc stearate, metal salt, phosphate salt, and potassium salt of 5-dimethylsulfoisophthalate (LAK-301 - nucleating agent developed for PLA). Non-isothermal crystallization measurements were performed at different cooling rates (0.3; 0.5; 0.7; 1.0 and 1.5 ° C). All nucleation agents increased the MVR of PLA except talc; the largest increase (9-fold and 24-fold) was the addition of metal salt. The additives did not fundamentally change the mechanical properties. All samples were rather brittle (the most brittle with LAK-301), the modulus of elasticity was around 1.2 GPa for all samples, the strength of PLA was increased the most by the addition of 1% talc (by 12%) and the elongation at break was increased by organic salt with SiO2. All samples with nucleating agents content of 1% were amorphous (crystalline content did not exceed 2%). Thus, the addition of reagents did not support the crystallization process during rapid cooling, even in the case of LAK-301. However, LAK-301 was acting as an excellent nucleating agent at slow cooling rates (1.5 °C / min and below). The nucleation activity of the additives decreased in the following order: LAK-301, organic salt with zinc stearate, talc, organic salt modified with amorphous SiO2 and phosphate salt. Samples with sodium benzoate and metal salt were crystallizing on cooling in several steps and it was not possible to use the method of Dobrev and Gutzow to evaluate the nucleation activity.

The theoretical part of the diploma thesis searches the production of Construction and demolition waste and their subsequent transformation into the final recyclate and its possible use in roads. Attention is focused on the use of mixed recycled material into subgrade of the pavement and the characteristics of tests that must be performed before its used to the road. The next chapters pai attention to the problematic properties of recyclates, foreign experience with the use of mixed recyclate in Construction and the possibilities of its development. The practical part verifies the suitability of mixed recycled material into subgrade of the pavement using laboratory tests. The tests are performer on individual mixtures of mixed recycled material with cement, blast furnace slag or cement dust in various percentages. The results are then compared and it is evaluated which mixtures show the best properties. Part of the practical part is also the economic evaluation of these mixtures against commonly used materials.

The master thesis dealing with problematic about durability of concrete, with use of recycled concrete and addition of silica additions. Predominant for resistance of concrete constructions is surface layer, through which aggressive gasses and liquids penetrate from surrounding environment. The most important indicator of concrete durability is ability of surface layer transmissions of aggressive substants. In experimental part will be defined the actual state of surface layer by normal testing methods. The transmissions of surface layer will be tested on concrete cubes. Tests for transmissions of air (method TORRENT), of water (method ISAT), of acid gases (dept of carbonation by quick test in 98% CO2) will be carried out and also strength tests. Assessment of positive or negative influence of additions and amount of cement on durability and mechanical properties of concrete will be discussed in conclusion.

The topic of this master's thesis is the development of composite materials based on inorganic binders for use in extreme conditions. It means especially geopolymeric or alkali activated materials (AAM) based composites. The theoretical part of this thesis summarizes knowledges about the development and use of alkali-activated materials, their structure and mechanisms of their formation. It also deals with the applicable raw materials for AAM and their exciters, which are in particular water glass and sodium hydroxide. There also have been a summary of the effects of high temperatures and chemicals on the mechanical properties of AAM and the requirements of standard EN 1504-3 for repairing materials. The task of the practical part was to develop a repair mortar for concrete structures based on AAM so that its production was as simple as possible, ie one-component materials. Gradually six recipes have been develeoped. Test specimens made from these recipes have been putted to selected tests according to the requirements of ČSN EN 1504-3.

In the theoretical part of the thesis are generally characterized hydraulically bound mixtures, their types, classification systems, manufacturing technology and the laying. There are also described experiences from abroad with the use secondary and recycled materials in hydraulically bound mixtures. The practical part deals with the experimental verification of the possibility of the use of secondary materials in hydraulically bound mixtures in construction of road infrastructure. In road laboratory Institute of road structures Brno university of technology was the five proposed mixtures, an assessment of their parameters with regard to the possibility of using these mixtures in the road sub-base layers. The work is also aimed at comparison of results elasticity modules reached laboratory testing and experimental measurements on road polygon.