|
|
Development of Historical Universal Mortar with Blended Binder
Lišovský, Martin ; Wagner,, Štěpán (referee) ; Fridrichová, Marcela (advisor)
The diploma thesis deals with development and properties of historic mortars, evolves and optimizes recipe of historicizing universal mortar with mixture binder, which have been evolves in previous phase. Binder system is based on lime hydrate and metakaolin and is modified with fast-pacing gypsum. Thesis follow up technological properties of mixtures of historicizing mortars and modifies them for current construction industry. It also follows effect of modification to phase composition of binder system and eventually rise of AFt phases.
|
|
|
Study of Preparation and Properties of Historic Mortars
Majerová, Jana ; Lang,, Karel (referee) ; Fridrichová, Marcela (advisor)
The diploma thesis is concerned with study of preparation and properties of historic mortars. In theoretical part, there is summarized the historic progress of mortars and their material composition. The experimental part is focused on proposition of mortar mixes. The diploma thesis referring to actual research on Institute of Technology of Building Materials and Components, FCE VUT in Brno. The base mixe of historical mortar came from this research. In experiment, there is the base mixe of historical mortar modified with gypsum. In the first phase of the experimental part the basic technological and aplication properties are assessed. The second phase of the experimental part is focused on the course of hydration of the binder in different environments and subseqeunt determination of the phase composition by X-ray diffraction analysis. The aim of the thesis is to determine the optimal amount of gypsum and to optimize the recipe of historical mortar.
|
|
|
Development and Propertied of Historic Masonry Mortar
Lišovský, Martin ; Kulísek, Karel (referee) ; Fridrichová, Marcela (advisor)
This bachelor’s thesis deals with development and propertied of historic masonry mortar, especially lime mortars and their modifications using pozzolan. In the recipe developed in the experimental part, metakaolin is used for the modification. The technological and application properties of mortars made from these formulations are then compared with the commercial mortar SCHWENK TM 5, which is modified by the suevite trass.
|
|
|
Effect of partial replacement of Portland cement by diatomaceous earth on selected parameters of cement mortar
Rousková, Jana ; Sedlmajer, Martin (referee) ; Rovnaníková, Pavla (advisor)
The subject of this thesis is selected parameters cement mortars with partial replacement of Portland cement diatomaceous earth. This work provides information on the basic properties of diatomaceous earth and its deposits with a focus on deposit in Borovany. From the properties is very important pozzolanic activity due to the high content of amorphous silica of this soil. The main use of diatomaceous earth is in the area filtration and is used widely as a nutritional supplement. In the building industry, diatomite can be applied as an admixture to mortar and concrete, where it can, with its abilities, improve some physical mechanical properties. In the experimental part was diatomaceous earth, in its raw and calcined form, tested as admixture for cement pastes and mortars. The main criterion for evaluating these composites was bulk density, flexural and compressive strength. It was also investigated mineralogical composition, microstructure, freeze–thaw resistance and sulfate resistance.
|
|
|
Lime Mortars Modified by Fine Ground Brick Body
Šmerdová, Ludmila ; Vyšvařil, Martin (referee) ; Rovnaníková, Pavla (advisor)
Natural pozzolanic materials played an important role in Ancient architecture. In the last decades and nowadays it is artifical pozzolan which especially finds its use as an additive to mortar and concrete to improve some, especially the mechanical properties. This master thesis deals with study of pozzolan type of fine brick powder which is a by-product of the production of calibrated bricks. Along with studying pozzolanic activity of brick powder, lime mortar with different proportions of brick powder as an additive or replacement of lime dust are investigated. What is observed is its impact on the consistency of these mortar, water absorption, strength in time or fracture-mechanical parameters of mortar. The results may indicate the possible potential use of this source of pozzolanic admixture in lime mortar and plaster which are nowadays mainly used for the restoration of facades of historic buildings.
|
|
|
Infusorial Earth - Reactive Admixture for Cement Composites
Zimmermann, Štěpán ; Žižková, Nikol (referee) ; Rovnaníková, Pavla (advisor)
The aims of this bachelor´s thesis are the properties and the use of diatomaceous earth as a partial replacement of cement in concrete. It provides information about the origin of diatomaceous earth, sedimentation of dead diatoms and variety of algae, including chemical and physical properties of the diatoms according to origin. The paper also contains information about significant deposits of diatoms, the manner and intensity of mining, including treatment of raw diatomaceous earth for further use. The main use of diatomaceous earth is in the filtration, which represents more than half of total consumption. An important factor for use in building is a high content of amorphous SiO2 and associated pozzolana activity of diatomaceous earth. The experimental part was carried out research on the influence of diatomaceous earth as pozzolanic admixtures on the properties of cement mortars. Tested specimens were obtained by adding 10% diatomaceous earth by weight of cement in the cement mortars. As admixtures were use three diatomaceous earth of different chemical composition, particle size and pozzolanic activity. The evaluated parameters were mortar density, flexural and compressive strength. The microsture of mortars were also observed. Test results were compared with those determined by reference mortars.
|
|
|
Properties of Zeolites and Their Use in Building Binders
Rousková, Jana ; Sedlmajer, Martin (referee) ; Rovnaníková, Pavla (advisor)
Zeolites, such as natural or synthetic aluminosilicates, have a wide range of applications. Their application in the construction industry tends to use zeolites as impurity type II. However, it has to prove their reactivity and affect the content of calcium hydroxide in the concrete. The aim is to determine the effect of zeolite as a partial replacement of cement in different concentrations on the mechanical properties of fine-grained concrete and consumption of calcium hydroxide.
|
|
|
Pozzolanic Activity of Silicon Dioxide
Barek, Jaroslav ; Žižková, Nikol (referee) ; Rovnaníková, Pavla (advisor)
The aim of this bachelor's thesis is to investigate and identify the present status of resources with dominant amorphous silicon dioxide content and summarize feasible test methods to assess pozzolanic activity. The use of pozzolan as a partial replacement of Portland cement reduces the carbon dioxide emitted per tonne of product and can also improve various physical properties of the resulting cementitious composites. Assessment of the pozzolanic activity of cement replacement materials is increasingly important because of the economic sustainability of cementing materials. The pozzolanic activity of wheat straw ash, silica fume, nanosilica, two diatomites, glass powder and expanded perlite have been investigated and compared using the strength activity index test, the modified Chapelle test and the pozzolanicity test in accordance with the European Standard EN 196-5. From an experimental investigation of seven different pozzolans, the following main conclusions can be drawn. In the case of an acid-base titration (determination of [OH–], the procedure specified in EN 196-5) is better to use Tashiro (mixed indicator) instead of required methyl orange, Tashiro changes color at the endpoint of a titration distinctly. Strength activity index: the procedure used was based on EN 450-1. In its current form, this procedure is misleading because of two other significant properties of the pozzolan, namely its density and its water-reducing/increasing capabilities. Based on the results of our experimental investigation, the current testing procedure is evaluated against an alternative in which the 25% pozzolan replacement for cement is performed on a volumetric basis and the volume fraction of water is held constant.
|
guest ::
