Potential applications of volcanic aluminosilicates

The article presents the contemporary possibilities of applications of micro-and nano-particles of volcanic tuff consisting of alluminosilicates and a series of spatial phases and oxide minerals. Describes examples of existing uses occurring in tuffs feldspars and micas, and the potential application of these materials include in environmental protection, construction, cosmetics, powder metallurgy, and as fillers in plastics. It also provides the possibility of using tuffs in metal alloys strenghtening particles and dispersion. Also presented results of studies of the structure and properties of selected Filipowice tuff

Possibility of Using a Geopolymer Containing Phase Change Materials as a Sprayed Insulating Coating - Preliminary Results

Geopolymers have been known for decades and classified as inorganic polymers, characterized by high resistance to high temperatures. They can be successfully used for the thermal insulation of buildings, especially in the foamed form. The addition of phase change materials (PCMs) in such materials may also increase the heat capacity of the materials, therefore, using them for building cladding can increase the thermal comfort of the building and prevent it from overheating. This study tests the addition of PCMs to geopolymers by spraying and presents the results. Additionally, the study includes preliminary experience concerning the technology of applying these materials, along with selected test results that assess the properties of the produced coatings. The results indicate that the addition of PCMs in the amount of 15% can increase the heat capacity of geopolymer materials by about 150-180%, and the foamed geopolymer coatings produced have a thermal conductivity in the range of 0.07-0.09 W/mK

Influence on permeability and pore structure of polyolefin fiber reinforced concrete containing slag

The purpose of this study is to assess the mechanical and microscopic properties of concrete containing different dosages of polyolefin fibers and slag through tests of compressive strength, resistivity, water absorption, mercury intrusion porosimetry and scanning electron microscopy. Test results indicate that the specimens containing slag have higher compressive strength, lower absorption, lower resistivity and denser porestructures than the control and specimen made with fibers. The specimens containing slag and polyolefin fiber demonstrated better performances in fiber reinforced concrete. Scanning electron microscopy illustrates that the polyolefin fiber acts to arrest the propagation of internal cracks. Still, there are cracks and weaknesses between fiber and paste that cause harmful ions penetrated easier

Impact of Flax Fiber Reinforcement on Mechanical Properties of Solid and Foamed Geopolymer Concrete

The main objective of this study is to develop the advanced composites for civil engineering applications as material for the building industry, especially for an insulation purpose. The research processes include several steps. Firstly, the prototype elements, such as bricks and elevation elements were performed from eco-friendly composite -flax fiber reinforced geopolymer. The elements were designed to take into consideration for environment. Geopolymers are environmentally friendly, sustainable, and resource efficient, including energy demand. Next, the wall was built from these elements and exposed during the three months in a relevant environment. The main conclusion of the research is that the kind of fibers is important for the mechanical properties of the composite, including the fact that for those different fibers could be more beneficial for different raw materials, giving higher strength properties. The significant influence on the mechanical properties of the composites has the adhesion between fiber and material used as a matrix. The adhesion depends among others on the previous treatment of the fibers

SYNTHESIS OF ZEOLITES FROM INCINERATION ASH AND SLAG

The work concerns the possibility of the use of secondary waste from waste incineration processes for the production of zeolites. The study used fly ash and slag from national waste incineration plants. The test materials were subjected to hydrothermal alkaline activation in aqueous solution of sodium hydroxide, the molar concentrations of the various variants. The research revealed the usefulness of this type of material for the synthesis of zeolites –obtained sodalite. Presents the results of analyzes of the SEM / EDS and XRD for the most efficient synthesis processes

Engineering Properties of Ternary Cementless Blended Materials

A new non-cement blended materials is developed as a full replacement of cement without alkali activator. This study was conducted to explore a suitable method for activating new ternary green materials with desulfurization gypsum, water-quenched blast-furnace slag and co-fired fly ash from circulating fluidized bed combustion as non-cement inorganic binder. Test subject was included flowability, compressive strength, absorption, total charge-passed from rapid chloride permeability test, chloride diffusion coefficient from accelerated chloride migration test and SEM observation. Test results indicate that a ternary mixture containing 1% desulfurization gypsum, 60% water-quenched blast-furnace slag and 39% co-fired fly ash was a suitable development in compressive strength. The new non-cement blended materials were performed a well compressive strength, lower absorption, and lower chloride diffusion coefficient. In addition, the compressive strength decreased as the inclusion of desulfurization gypsum increased. It was concluded that using desulfurization gypsum alone decreased the setting time and compressive strength. SEM micrographs were verified the development in compressive strength originated from the C-S-H and C-A-S-H gel produced by Ca(OH)2, SiO2, and Al2O3

Development and Characterization of Thermal Insulation Geopolymer Foams Based on Fly Ash

The main purpose of the article is to present the differences in the parameters of geopolymer foams obtained in the same way, which is associated with difficulties in controlling the foaming process. Difficulties in controlling the foaming process of geopolymers are the direct reason for the lack of implementation of such materials nowadays. The article shows the results for experimental research, especially research into insulation, physical, and mechanical properties for the designated foamed materials. Microspheres (75%), sand (5%) and fly ash (20%) were used to produce foamed geopolymers. Hydrogen peroxide was the foaming agent. Heat conduction coefficients of 0.08-0.07 W/mK were obtained. The material density was obtained at the level of 363-375 [kg/m3] and the compressive strength was 520-683 [kPa]. The results showed that geopolymers can be a good alternative to conventional insulation materials, but the foaming technology should be developed so that it is stable and allows for reproducible material parameters

Green Building Materials for Circular Economy - Geopolymer Foams

This study aims to design and investigate foamed geopolymers as a green material dedicated to the circular economy. For synthesis as raw material, the main waste materials of two Polish coal mines, Wieczorek and Staszic, are applied. Additionally, various foaming methods are employed to utilize the by-product of energy production, especially the fly ash generated by the Skawina power plant. In this study, the main issues addressed are related to the selection of the most appropriate foaming agent and the optimization of the process parameters, including temperature, time, and mixture components. Hydrogen peroxide, aluminum powder, and a commercial foaming agent are selected as foaming agents in this research. During the process of sample preparation, stabilizers are applied in the form of polyglycol and cellulose. Through the conducted test, the results show that hydrogen peroxide and aluminum powder emerged as the two most optimal foaming agents

Mild therapeutic hypothermia after out-of-hospital cardiac arrest: What does really matter?

Background: Mild therapeutic hypothermia (MTH) is a recommended treatment of comatose patients after out-of-hospital cardiac arrest (OHCA). The aim of the study was to examine determinants of clinical outcome in OHCA survivors treated with MTH and variables associated with MTH induction time.Methods: Presented herein is an analysis of combined results from a retrospective and a prospective observational study which included 90 OHCA survivors treated with MTH from January 2010 to March 2018. Multivariate regression analysis was performed to determine variables associated with poor neurologic outcome (Cerebral Performance Category 3–5), mortality, and prolonged induction time.Results: At hospital discharge, 59 (65.6%) patients were alive, of whom 36 (61%) had a good neurologic outcome. Older patients (odds ratio [OR] 1.07, 95% confidence interval [CI] 1.03–1.12) with lower Glasgow Coma Scale (GCS) (OR 0.49, 95% CI 0.30–0.80) were at higher risk of poor neurological outcome. The predictors of in-hospital death included: older age (OR 1.08, 95% CI 1.02–1.13), lower GCS score (OR 0.47, 95% CI 0.25–0.85), presence of cardiogenic shock (OR 3.43, 95% CI 1.11–10.53), and higher doses of adrenaline (OR 1.27, 95% CI 1.04–1.56). Longer induction was associated with shorter cardio-pulmonary resuscitation (CPR) (unstandardized coefficient –3.95, 95% CI –7.09 to –0.81) and lower lactate level (unstandardized coefficient –18.55, 95% CI –36.10 to –1.01).Conclusions: Unfavorable neurologic outcome in OHCA patients treated with MTH is associated with age and lower GCS score. Risk factors for in-hospital mortality include age, high-dose adrenaline administration, lower GCS score and presence of cardiogenic shock. CPR duration and lactate level were predictive of prolonged MTH induction time

SMART geopolymers, an ERA-MIN project

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