Foam Glass Research Articles

ВЛИЯНИЕ АЛЮМОСИЛИКАТОВ НА СВОЙСТВА ПОРИСТОЙ СТЕКЛОКЕРАМИКИ ИЗ КРЕМНИСТЫХ ПОРОД

The article presents the results of the study of the structure, physical-mechanical and thermophysical properties of glass-ceramic materials. The charge mixture for the production of samples was obtained from siliceous rocks, kaolin, bentonite, Na2CO3 and KCl. Joint mechanochemical activation of the components was carried out in a planetary ball mill. The charge mixture obtained was fired in a muffle furnace at a temperature of 850 °C. The experimental results were obtained using the method of X-ray phase (XRF) analysis. The physical-mechanical and thermophysical properties of the samples are determined. The developed materials (in the form of blocks) have an apparent density of 308 to 409 kg/m3, flexural strength up to 3.2 MPa and compressive strength up to 13 MPa, thermal conductivity from 0.081 to 0.107 W/m∙°С, limiting operating temperature up to 890 °С inclusive. The materials obtained are superior in many respects to foam glass and glass ceramics from industrial waste. They can be used as thermal insulation in the construction of industrial and civil facilities.

Foam Glass Functionalized with Iron Compounds: A Strategic Material for Heterogeneous Photocatalysis

Foam Glass Functionalized with Iron Compounds: A Strategic Material for Heterogeneous Photocatalysis

Foam Glass Functionalized with Iron Compounds: A Strategic Material for Heterogeneous Photocatalysis

Foam Glass Functionalized with Iron Compounds: A Strategic Material for Heterogeneous Photocatalysis

The Synthesis of Surfactant Coated Glass Foam to Extract and Determine Trace Quantities of Polycyclic Aromatic Hydrocarbons in Drinking Water

The Synthesis of Surfactant Coated Glass Foam to Extract and Determine Trace Quantities of Polycyclic Aromatic Hydrocarbons in Drinking Water

Environmental Performance of the Alkali Activation for the Glass Foam from Waste Glass

Environmental Performance of the Alkali Activation for the Glass Foam from Waste Glass

SYSTEM ANALYSIS OF TECHNOLOGICAL PROCESSES

The article discusses ways to solve engineering problems in the study of technological processes using methods of system analysis. The essence of this method is to study the technology as a cybernetic system with an assessment of the" reactions” of this system to external influences formed during an active experiment. At the same time, optimization problems are solved analytically. Analytical optimization is based on two main principles. The regression equations obtained as a result of processing experimental data and testing statistical hypotheses are models that adequately describe real processes. Each of these equations is an algebraic function of several variables, to which methods of mathematical analysis are applicable, including the study of extremums of functions in partial derivatives. The next step is to develop a process algorithm and develop computer programs that allow you to select the composition and predict the properties of the product. As an engineering interpretation, it is possible to construct optimized nomograms that allow solving both direct and inverse problems; that is, predicting the result or selecting technological factors. The research methods described in the article are implemented in the study of technologies of cellular concrete, foam concrete, cement-polymer concrete and products made of mineral wool and foam glass. As an example, the article considers the optimization of the selection of the composition of fine-grained concrete reinforced with chopped glass fiber. The implementation of the developed method allowed us to determine the optimal value of the determining parameters, including the consumption of fiber and plasticizer, as well as to form a method for studying the properties of products.

Waste-to-Reuse Foam Glasses Produced from Soda-Lime-Silicate Glass, Cathode Ray Tube Glass, and Aluminium Dross

Aluminium dross is a hazardous industrial waste generated during aluminium production. It contains metallic oxides of aluminium and magnesium, other phases (aluminum nitride), and residues of fluxes and salts from the melting process of aluminium. Discarding this by-product is considered an environmental and economic challenge due to the high reactivity of dross with water or even air humidity. After removing the hazardous components from the as-received dross, one of the optional approaches is to incorporate the treated dross into construction materials. Dross is applied in several types of research as a secondary raw material source for alumina, clinker, cement or glass-ceramic production, but only a few papers focus on the usage of dross as a foaming agent for foams. Even fewer research are reported where dross was applied as a basic component of foam glasses. In this work, foam glasses were produced completely from waste materials: Aluminium dross, container (SLS) glass, and cathode ray tube (CRT) glass. The research holds several specificities, i.e., combining two industrial waste materials (CRT glass and dross), and adding an increased amount from the wastes. The physical and mechanical characteristics were examined with a special focus on the effect of the foam glass components on the microstructure, density, thermal conductivity, and compressive strength.

UNCONVENTIONAL TECHNIQUE USED TO MANUFACTURE POROUS HIGH-STRENGTH GLASS FOAM

The paper presents experimental results obtained in the manufacturing process of porous high-strength glass foam for thermal insulation in buildings made of glass waste and kaolin clay as raw materials and dolomite as a foaming agent. The paper’s originality is the use of the unconventional microwave heating technique. The best product manufactured by this technique was that sintered at 1050 ºC using 18 wt.% kaolin clay and 3.5 wt.% dolomite. The product characteristics were: the apparent density of 0.66 g·cm-3, the thermal conductivity of 0.155 W/m·K, the compressive strength of 5.3 MPa and a microstructural homogeneity with pore size between 0.20-0.50 mm.

Foam Glass Crystalline Granular Material from a Polymineral Raw Mix

The article is devoted to the development of resource-saving technology of porous granular materials for energy-efficient construction. The relevance of the work for international research is to emphasize expanding the raw material base of porous lightweight concrete aggregates at the expense of technogenic and substandard materials. The work aims to study the processes of porization of glass crystalline granules from polymineral raw materials mixtures. The novelty of the work lies in the establishment of regularities of thermal foaming of glass crystalline granules when using waste of magnetic separation of skarn-magnetite (WMS) ores and lignite clay. Studies of liquid glass mixtures with various mineral fillers revealed the possibility of the formation of a porous structure with the participation of opoka, WMS and lignite clay. This is due to the presence in the materials of substances that exhibit thermal activity with the release of a gas phase. The foaming efficiency of the investigated materials increases when combined with glass breakage. The addition of WMS and lignite clay to the glass mixture increases the pore size in comparison with foam glass. The influence of the composition of raw mixtures on the molding and stability of granules is determined. The addition of sodium carbonate helps to strengthen the raw granules and reduce the softening temperature of the mass. The composition of the molding mixture of glass breakage, liquid glass and a multicomponent additive is developed, which provides an improvement in the molding properties of the glass mass, foaming of granules at a temperature of 750 °C. Foam glass crystalline granules have polymodal porosity, characterized by a density of 330–350 kg/m3, a compressive strength of 3.2–3.7 MPa, and a thermal conductivity of 0.057–0.061 W/(m·°C). Accordingly, the developed granules have a high potential use in structural and heat-insulating concretes.

A Passive Wood-Based Building in Slovakia: Exploring the Life Cycle Impact

The aim of the study is to point out the burden of passive wood-based buildings throughout the life cycle from the environmental point of view to better understand the consequences and importance of building design in Slovakia. The analysis was carried out according to the Life Cycle Assessment methodology. The results were calculated by the CML-IA baseline method. The impacts of the product stage and operational energy use were the highest throughout the considered life cycle. Substances contributing to eleven impact categories were identified. Foundations, especially foam glass, were found to bear the majority of the impact of the overall construction materials. The normalization category showed considerable impact on marine aquatic ecotoxicity mainly due to building energy consumption over the course of 50 years. Loads connected to the replacement stage were the third highest. The study also proved high demand on elements of photovoltaics.

Predictable building enveloping based on enhanced glass foam insulation with heat reflective properties

Commercial glass foam was covered with 1–4 layers of coating containing titanium dioxide (TiO2) to study thermal efficiency and changes in the reflection and emissivity spectrum in correlation with the number of layers. The morpho-structural and optical properties of the coated foam glass were studied by X-ray diffraction (XRD), Fourier transform-infrared (FT-IR), Raman and ultraviolet-visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM) and laser microscopy. Structural characterization by X-ray diffraction revealed amorphous nature of the foam glass and the presence of rutile structure (natural tetragonal crystal structure) for TiO2. We find that the thermal reflective and heat-insulating properties are significantly improved by applying the TiO2 coating so that the functionalized foam glass presents reflectance with 84.6% higher in foam glass covered with the fourth layer compared with non-layered glass foam. It was demonstrated that the use of reflective coatings can reduce the foam glass surface temperature under hot summer conditions by 47.3% which led to the reduction of heat transfer from 55 W∙m−2 in the case of uncovered glass foam to about 28 W∙m−2 for glass foam coated with four layers of TiO2. The foam glass coated with TiO2 is an effective method to increase its thermal screen performance, reflecting a large part of the solar radiation which makes it efficient for thermal insulation of exterior parts of a building that may be exposed to solar and IR radiation, reducing heat gain in buildings.

Customizing the properties of borosilicate foam glasses via additions under low sintering temperatures with insights from molecular dynamics simulations

We computationally and experimentally investigate the impact of a series of additions to the physical and mechanical behaviors of borosilicate foam glasses sintered at low temperatures for customized engineering needs. A trend of enlarging and reducing in density and strength is shown when adding Ca(NO3)2 and Ba(NO3)2, and constantly increasing trends are found for CaSO4 and CaCO3. The molecular mechanism of the CaCO3-added foam glasses is elucidated with molecular simulations, where the enlarged strength and density are attributable to more uniformly distributed pore microstructures. The reinforcing effects of mullite fibers are explored, where a general trend of enlarging in density and strength is shown. Total porosity and volume-absorption rate are inversely correlated with strength and density, respectively, guiding a potential pathway for targeted design. By understanding the effects of pore microstructures, this study establishes a novel material process-structure-property perspective, inspiring future efforts in mass-producing low cost, high-performance environmentally friendly materials.

Surface-dependent gas equilibrium of semi-volatile organic compounds on glass, wood, and polyurethane foam using SPME-GC/MS

The surface-dependent evaporation behavior of phthalates as semi-volatile organic compounds (SVOCs) on glass, wood, and polyurethane foam (PUF) was investigated. Three phthalates of di-2-ethylhexyl phthalate (DEHP), butyl benzyl phthalate (BBP), and dibutyl phthalate (DBP) were studied to compare the amount of gases vaporized from their surfaces. A 10 mL silicate glass vial was used to compare the gas equilibrium of the phthalates after 2 h. The gases accumulated in the air were transferred to a solid-phase microextraction (SPME) column and analyzed by gas chromatography-mass spectrometry (GC-MS). As correlated with the physicochemical properties of the phthalates, including molecular weights and vapor pressure, the surface-air partition coefficients (Ksa) were found to be in the range of 101–105 m, 106–107 m, and 107–109 m on glass, wood, and PUF, respectively, implying that a significant amount of phthalates are retained on wood and PUF surfaces as compared to glass, and only a trace amount of phthalates can be volatilized into the air, especially the less volatile DEHP. The three-dimensional (3D) morphologies of glass and wood were also examined using a white-light interferometric surface profile microscope and an atomic force microscope (AFM). In contrast to smooth glass surfaces within the sub-micrometer vertical range, the wood surfaces exhibited uneven irregular structures at a height of 5–30 μm. The rough wood surfaces were found to adsorb substantial amounts of gases to prevent the effective volatilization of phthalates into the air, especially the low molecular DBP. Our results imply that wood and PUF surfaces may be superior to glass surfaces in storage and reduction of phthalates in the air, especially DBP.

Development of lightweight structural concrete with the use of aggregates based on foam glass

Lightweight concretes are increasingly being used in the construction industry, either for the overall lightweighting of the structure itself, reducing material consumption for construction and thus CO2 emissions, or for specific reasons such as improving the thermal insulation properties of the structure or acoustic properties. Today, lightweight concretes with lightweight expanded aggregates (expanded clay, agloporite) are most commonly used. This paper deals with the production of lightweight concretes lightweighted with foamed glass-based aggregates. Foamed glass is a lightweight material characterised by a very good ratio of thermal insulation and mechanical properties. Foamed glass is made of approximately 90% recycled glass waste (mostly mixed), which cannot be used in any other way, as well as water glass and glycerine. When concrete is lightened with foamed glass, these concretes achieve unique properties while conserving primary aggregate resources, avoiding landfilling of glass waste and efficiently using the waste material to produce lightweight concrete with higher added value. The paper discusses the possibilities of developing lightweight structural concretes using glass foam-based aggregates to achieve higher strength classes while reducing the weight and thermal conductivity of the concrete. As part of the research work, new types of lightweight concrete with a bulk density in the range of 1750–1930 kg/m3 and a thermal conductivity from 0.699 to 0.950 W/(m·K) were developed.

Sustainable Ways and Methods of Recycling Epoxy Fiberglass Waste

This article presents two technological ways of recycling the wastes of the production and application of products made of highly oriented fiberglass bound by the epoxy matrix. The first technology is aimed at shredding the epoxy-based products obtained by pultrusion to create fine and ultrafine powders (up to 2-10 microns) used as fillers in various composites. The second technology offers a way to obtain coarse powders with a particle size of up to 100 microns, used in the composition of heat-insulating materials and fire-retardant intumescent coatings. Proposed is the mechanical grinding of fiberglass to a finely dispersed state with subsequent heating to a temperature of 400 °C in the presence of a foaming coke and liquid glass. This technology allows the full utilization of waste from the production and application of epoxy fiberglass, such as windmill blades and parts of molded products, leading to the creation of an environmentally friendly fire-resistant and heat-insulating material in the form of plates, blocks and other products with operation temperature up to 400C, as well as fire retardant coatings for building materials and structures. By varying the content of the foaming agent and soluble glass in the composition of the intumescent mixture, one can regulate the average density, thermal conductivity and strength of the material within significant limits, achieving characteristics that exceed those of traditional heat-insulating materials. The proposed material based on recycled epoxy fiberglass is inflammable and resistant to unfavorable environmental impacts; it has high biostability and provides heat and mass transfer during the operation in buildings and structures.

Improving the shielding efficiency and weight reducing of the radio-absorbing coating by adding a matching layer

The spectra of complex permittivity of the composites consisting of rubber silicone compound and electroconductive fine-dispersed silver-coated copper powder were investigated. To enhance the effectiveness of the composite interaction with microwaves and reduction of its weight and dimensions characteristics two and three-layer constructions were produced. Matching layers were made of foam glass material with addition SiC and Fe3O4.

Aluminium dross/soda lime glass waste-derived high-quality glass foam

This work introduces for the first time the use of waste aluminium dross obtained from the aluminium industry as a foaming agent to produce sustainable foam glasses from soda-lime glass powders derived from the lapping machine. The resulting foam briquettes (8ⅹ8ⅹ8 cm3) have a crack-free, 3-D cellular structure with closed pores whose geometries varied between elliptical-, pentagonal-, and hexagonal-shaped constructions. These glass foams demonstrate a lightweight (≥0.28 g/cm3), high CCS (≤12 MPa), low thermal conductivity (0.11–0.21 W/m-K), and contain more than ∼ 85 vol.% gas bubbles enclosed between 15 vol.% impervious glass walls. These properties are in line with the requirements of the international standard for commercial glass foams, revealing their strong capability to be used in potential applications in sustainable buildings and energy efficiency in the industry.

Risk of Using Capillary Active Interior Insulation in a Cold Climate

The retrofitting of cultural heritage buildings for energy efficiency often requires the internal thermal insulation of external walls. Most of the in situ studies of capillary active interior insulation were performed in mild oceanic climate regions, and they showed an excellent performance. However, as a large part of Central–Eastern Europe belongs to a continental climate with cold winters and long periods of temperatures below the freezing temperature, the applicability of the capillary active interior insulation in cold climate was studied. The hydrothermal behaviour of the three walls was determined—each consists of one of three different interior insulations—and the original wall is made of historic regular solid bricks. Two interior thermal insulations were capillary active (aerated cellular concrete, calcium silicate) and one vapour-tight (glass foam). A hot box–cold box experiment and a steady-state model were used to demonstrate an increase in the original wall mass due to the water condensation only when the capillary active interior insulation is used. The combination of the water condensation and the low sub-zero temperature may lead to a risk of freeze–thaw damage to the original wall. The numerical simulation of the water vapour condensation for the considered walls for the Slovenian town Bled with sub-zero average winter temperatures was performed to obtain the whole temperature and moisture profile. It showed good agreement between an experimentally and numerically obtained amount of water condensation. The capillary active interior insulation proved to be unsuitable for improving the thermal insulation of buildings in cold continental climate, and only a vapour-tight system can be recommended.

USE OF MICROWAVE RADIATION FOR SEPARATION OF LIQUID GLASS HEAT INSULATION MATERIALS

The study of the thermal insulation market of Ukraine showed that the market is dominated by aerated concrete and silicates, which are used as thermal insulation materials at an average density of 300-500 kg / m3. Their disadvantages include high values of water absorption and hygroscopicity, as well as very low flexural strength, because this material does not have elasticity and the use of small bending forces leads to its cracking. Foam glass has a set of operational properties that meet the highest regulatory requirements. Foam glass is the strongest of all effective thermal insulation materials, but this material is fragile. It is sensitive to vibration - induced damage. In addition, the technology of production of foam glass is quite complex and requires high energy consumption, as a consequence, the cost of this material is high. Therefore, it was important to develop thermal insulation material with the appropriate level of performance while reducing production costs. This was achieved by using energy-saving microwave technology to swell liquid glass materials. This technology is based on the simultaneous swelling of the liquid glass granulate and the binder under microwave radiation, which, due to the volumetric heating of the liquid glass composition, allows to obtain a strong monolithic material with a rigid, homogeneous and mostly closed-porous structure. The production of thermal insulation materials is proposed to be carried out on the basis of liquid glass granulate, because the introduction of granules reduces the deformability and shrinkage of the material and prevents its cracking, increases its strength, because the granular material has a certain plastic deformation, reduces water hygroscopicity. granules swell to form a compacted shell, which slows down the absorption kinetics of water and its vapor. The monolithic granules are proposed to be carried out with a binder that foams not only due to the release of water, but also with the help of a gasifier, because this technology will allow uniform distribution of the binder in the intergranular space, thus forming a more homogeneous structure of the material, which has a positive effect on its physical and mechanical characteristics.

Loading Effect of Hollow Glass Microsphere (HGM) and Foam Microstructure on the Specific Mechanical Properties and Water Absorption of Syntactic Foam Composite

AbstractEpoxy syntactic foams (SF) filled with hollow glass microspheres (HGM) were prepared by simple resin casting method and characterization in this study. The effect of varying the amount of HGM on the specific mechanical and water absorption properties of SF composites were investigated. Five different composition of SF (SFT60-0.5 to SFT60-2.5) were compared with the neat epoxy matrix. The wall thickness of the microballoons differ because of its different percentile size distribution (10th, 50th and 90th), which reflects in its density variation. The results show that the specific tensile and flexural strength increases with an increasing filler (HGM) content. The density of SF filled with HGM reduces with increasing volume fraction of filler content. Scanning electron microscopy was done on the failed samples to examine the fractured surfaces. The water absorption capacity of the SF was also investigated as it relates to the HGM volume fraction variation. All the syntactic foam composition shows a better diffusion coefficient capacity than the neat epoxy resin. This makes it applicable in structural purposes and several marine application products such as Autonomous Ultimately Vehicle (AUV).