Jana Boháčová

Alkali-Activated Building Materials Based on Blast Furnace Slag and Non-Standard Aggregates

Alkali-Activated Building Materials Based on Blast Furnace Slag and Non-Standard Aggregates This paper deals with alkali activated materials based on fine grained granulated blast furnace slag. Waste aggregates from building materials and building demolition are used as the filler. Its mechanical and durability parameters are tested. Results may contribute to further alkali activated system development and research focused on practical applications in the building industry. Alkalicky Aktivované Stavební Hmoty na Bázi Vysokopecní Strusky a Nestandardního Kameniva Příspěvek se zabývá alkalicky aktivovanými materiály na bázi jemně mleté granulované vysokopecní strusky. Současně jsou v těchto hmotách jako plnivo použity odpadní suroviny jak z výroby a úpravy stavebních surovin a hmot, tak také z oblasti demolic staveb. Vytvořený materiál je testován na mechanické a trvanlivostní parametry. Výsledky mohou přispět k dalšímu výzkumu a vývoji alkalicky aktivovaných systémů se zaměřením na praktické využití ve stavebnictví.

Properties of Thermal Insulating Alkali Activated System Research and Development

Properties of Thermal Insulating Alkali Activated System Research and Development The paper deals with laboratory research and development of alkali activated system with thermal insulation properties, where, such as additive, low density materials are used. The experiment is focused on strength and heat conductivity of prepared substances. In research five kinds of mixtures were prepared. The values of compressive strength and thermal conductivity of tested admixtures qualitatively correspond to commercially available building material. Results are foundations for next lightweight alkali activated system development and research focused on practical application in building. Vývoj a Výzkum Vlastností Tepelně Izolačních Alkalicky Aktivovaných Systémů Příspěvek se zabývá laboratorním výzkumem a vývojem alkalicky aktivovaných systémů s tepelně izolačními vlastnostmi, ve kterých je jako plnivo použit materiál s nízkou objemovou hmotností. Experiment je zaměřen na pevnosti a tepelnou vodivost vytvořených hmot. V rámci výzkumu bylo připraveno pět druhů záměsí. Hodnoty pevnosti v tlaku a součinitele tepelné vodivosti u zkoumaných receptur kvalitativně korespondují s komerčně dostupnými stavebninami. Výsledky jsou základem pro další výzkum a vývoj lehčených alkalicky aktivovaných systémů se zaměřením na praktické využití ve výstavbě.

Preparation and Properties of Pressed Metakaolin and Fly Ash Based Alkali-Activated Binders

Metakaolin, fly ashes and other secondary raw materials serves as suitable input in preparation of alkali-activated binders. This work deals with preparation of alkali-activated materials based on metakaoline and fly ash. Mixtures were prepared with a minimum of mixture water, ready for pressing. Prepared specimens were tested for tensile strength and pressure strength, resistance to high temperatures, frost resistance and resistance to water and salt.

Mechanical Properties of Alkali-Activated Material with Waste Aggregate According to Porosity

Mechanical properties of alkali-activated materials are intensively studied nowadays. Great attention is paid to the economic problems and the effort to reduce the price of the finished product. This paper deals with usage of secondary raw materials from building industry used as aggregate for alkali-activated material. The mechanical and durability properties are tested and compared with porosity determined by mercury porosimetry.

Testing of Possible Use of Fine-Grained Alkali Activated Composites in the Construction Industry

Alkali-activated materials are formed by the alkaline activation of inorganic materials and are characterized by the wide range of potential use. The objective of experiment was to investigate the possibility of use fine-grained alkali activated composites in the construction industry. Selected properties of alkali-activated systems based on granulated blast furnace slag and fine-grained aggregates were determined. At the beginning of the experiment, different samples prepared of 3 types of activators were tested, basic properties (time of workability, initial and final setting time, compressive and flexural strength) and also a possibility of selected retarder use was determined. Then, samples with the best potencial to presumed use were tested in detail and a possibility use as a substitute for selected construction materials were evaluated. On the basis of determined properties, prepared composites could be used as reprofiling mortars, materials for cracks repairing or socle plasters.

Comparison of Selected Properties of Portland Cement Based Materials and Alkali Activated Materials Based on Granulated Blast Furnace Slag

Alkali activated systems are materials formed by alkali-activation of latent hydraulic or pozzolanic materials. The outcome is a polymeric structure with properties comparable to materials based on cement.The principle of the experiment is to compare selected properties of alkali-activated materials based on blast furnace slag and using various types of activator (sodium water glass, potassium water glass, DESIL AL and sodium metasilicate) to binders based on white and Portland cements of the highest quality. The samples were left for one year in environments simulating the conditions in the interior and exterior. Selected physical-mechanical properties were evaluated and compared.

Thermal Analysis Application in Study of Alkali-Activated Blast Furnace Slag

The most modern methods are used for study of alkali-activated material nowadays. Due to structure of these materials which is less structured most of these methods provide only limited information. Thermal analysis is partially applicable to alkali activated materials based on blast furnace slag. The article describes the application possibilities of thermal analysis to the study of thermal transformations of these materials and their applicability to the description of the tested structure.

Alkali Activation of Blast Furnace Slag by Various Types of Activators

Alkali-activated systems, formed by the alkaline activation are inorganic materials characterized by the potential of ecological use. The objective of experiment was to investigate the influence of different activators on selected properties of alkali-activated systems based on granulated blast furnace slag. At the beginning of the experiment, 21 different samples prepared of 12 types of activators were tested to the basic properties. Then, selected samples with the best potencial to use were tested to compressive and flexural strength, frost resistance and surface resistance to chemical de-icing substances. The initial setting time achieved 25 - 95 minutes and final setting time achieved 30 - 105 minutes, compressive strengths were in the range 40 - 100MPa, frost resistance and resistance of surface to water and defrosting chemicals were confirmed.

Thermal Insulating Alkali-Activated Materials with Lightweight Aggregate

The paper deals with laboratory research and development of alkali activated system with thermal insulating properties where low density materials are used. The experiment is focused on strength and heat conductivity of prepared substances. In research five kinds of mixtures were prepared. The values of compressive strength and thermal conductivity of tested admixtures qualitatively correspond to commercially available building material. Results are foundations for next lightweight alkali activated system development and research focused on practical application in building industry.

Thermoanalytical Study of Binders Containing Pozzolanic and Latent Hydraulic Materials

The course of hydration and the resulting structure in binders containing pozzolan and latent hydraulic materials is still widely investigated area. In this work we studied the course of hydration by calorimetry of cement with several types of different reactive admixtures. After determining the results of hydration the DTA / TG analysis of the resulting material was carried out. Qualitative comparisons of resulting products are primarily implemented.