Taguchi-based investigation of molding methods and sintering parameters on foam glass performance

In response to the challenge of noise control during vehicle operation, this paper conducts a detailed study on the impact of partial parameters of composite structures based on porous elastic polyester foam and lightweight glass wool using acoustic simulation software and the finite element-transmission matrix coupling (FEM-TMM) algorithm. The study employs controlled variable methods to investigate the effect of individual variables on the results, deriving schematic diagrams of acoustic coefficients under various parameters and analyzing the variation patterns of sound absorption and insulation performance with different parameters. The research indicates that increasing material thickness, bending rate, and porosity can enhance sound absorption performance by 20 % to 70 %. This provides a certain direction for the multi-layer composite construction and optimization of noise reduction materials. Additionally, it demonstrates that the finite element-based transmission matrix method is applicable to the investigation of acoustic characteristics of composite structural materials, achieving selective optimization of acoustic performance in the frequency domain.

To extinguish flammable polar liquids, it is proposed to use a multicomponent fire extinguishing system consisting of one or two layers of wetted lightweight bulk materials. It has been established that wetting bulk materials leads to a significant increase in the following components of fire extinguishing action: cooling, insulation, and dilution. In addition, the introduction of water into the fire extinguishing system leads to a decrease in the concentration of vapors of polar flammable liquids above the fire extinguishing layer of bulk materials due to their absorption by water. Crushed foam glass with a granule size of 10-15 mm was selected as a bulk material for the formation of the base layer of the fire extinguishing system. To improve the insulating properties of the base layer, it is proposed to apply swollen perlite with a granule size of 1.0-1.4 mm or swollen lamellar vermiculite with a scale size of 1 × 2.5 mm to its surface. Such sizes of perlite and vermiculite particles enable them to fill the cavities between the granules of the foam glass base layer, which leads to an increase in the insulating properties of the fire extinguishing system. The following were experimentally determined: bulk density, buoyancy in methanol, ethanol, propanol-2, and acetone, moisture retention of bulk materials, and the fraction of material that spilled through the foam glass layer. The fire extinguishing capacity of the proposed fire extinguishing systems based on bulk materials in the case of extinguishing polar flammable liquids was experimentally determined. The systems based on bulk materials have a combined fire extinguishing effect by the following mechanisms of combustion termination: cooling, insulation, and dilution. It is concluded that the advantages of the proposed system in comparison with existing fire extinguishing agents for polar flammable liquids are substantiated.

Construction of an interpenetrating network structure based on skeleton reconstruction of melamine foam and ultrafine glass fiber and property investigations

Abstract This work uses lightweight geopolymers from metakaolin-based geopolymer in 70 vol% and foam glass as a lightweight aggregate in 30 vol%. The study used three foam glass collages made from glass waste and foaming at 750–775–800 °C. The thermal conductivity value range of 0.18–0.28 W m−1·K−1 of the lightweight geopolymers proves its effectiveness as a thermal insulating material. The water absorption values range from 2.83–4.06 wt%. After 21 freeze-thaw cycles at −20 °C, the weight loss range of lightweight geopolymers samples was 20.02–34.09%, and the compressive strength reduction range was 32.5–77.9%. The lightweight geopolymer with foam glass sintered at 800 °C had 20.02% weight loss and 32.5% compressive reduction lower than other samples due to strong binder-aggregate bonding.

In Ukraine, about 80 % of the existing housing stock was built with low thermal resistance of building envelopes, which leads to excessive consumption of energy resources. This necessitates thermal modernization of buildings to improve their energy efficiency. The article investigates changes in the thermal and physical characteristics of thermal insulation materials as part of building envelopes under operating conditions. The influence of the service life on the thermal properties of various thermal insulation materials is analyzed. The aim of the study is to experimentally analyze changes in the thermal and physical characteristics of heat-insulating systems common in construction throughout their service life. Traditional thermal insulation materials, such as expanded polystyrene, polyurethane foam, foam glass and basalt wool, are considered. Expanded polystyrene is an affordable and effective insulation material, but its main disadvantage is flammability. Foam glass, although a non-combustible material, requires significant energy inputs at the production stage. To evaluate the thermal and physical properties of different options for thermal insulation of wall enclosing structures, the thermal modernization of an administrative building was carried out and a set of measures for analyzing heat losses was developed. Experimental data obtained during the long-term operation of thermal insulation systems were compared. The experimental data on the distribution of heat flux density and temperature fluctuations in the section of the wall envelope insulated with different thermal insulation materials were analyzed and processed. The values of thermal conductivity coefficients for the studied thermal insulation materials were calculated. Also, the values of the thermal conductivity coefficient of thermal insulation materials were compared with the normative values and with the results of research for previous years. Bibl. 17, Fig. 6, Tab. 1.

Evaluation of the influence of pore structural parameters on the mechanical properties of foam glasses via in-situ micro-CT mechanical testing

The current study presents the development and optimisation of foam glass manufactured from recycled glass shards and expanded ground perlite, targeting enhanced structural and thermal performance for sustainable building applications. By investigating various particle size fractions (“125 μm”, “250 μm”, “500 μm”) and sintering temperatures (800–850 °C), we achieved a foam glass with superior compressive strength and uniform porosity. Notably, samples utilising a homogeneous 500 μm particle fraction sintered at 850 °C exhibited the highest compressive strength of 2.17 MPa, coupled with open porosity uniformity and stable structural matrix formation. Density values in this fraction decreased from 321 to 263 kg/m3, indicating effective foaming and well-developed open porosity that balances mechanical integrity and thermal insulation. The optimised thermal regime minimised crystalline phase formation, preserving low thermal conductivity and mechanical stability. Compared to heterogeneous composites, the homogeneous fractions demonstrated significantly improved strength-to-porosity ratios, ensuring predictable mechanical performance and competitive thermal insulation properties. These findings underline the material’s potential as a cost-effective, environmentally friendly insulation solution that meets or exceeds existing standards, with promising applications in energy-efficient construction.

Study on the feasibility of using foam glass in Engineered Materials Arresting System

A novel fenton-like catalyst for efficient degradation of tetracycline: Application of the concept of "treating the wastes with wastes".

The aim of this work was to study the physicochemical processes occurring in the raw material mixture during thermal treatment and the kinetics of its foaming, with the ultimate goal of optimizing the technological parameters for foam glass production. The primary objective was to investigate the influence of temperature-time foaming regimes on the formation of the material's structure. The experimental charge consisted of highly dispersed float glass powder and anthracite. It was determined that the formation of an optimal porous structure is achieved at a temperature of 850 °C with a holding time of 20 minutes. The obtained samples exhibited a bulk density of 0.20 g/cm³, meeting the requirements for thermal insulation foam glass. The results obtained can be utilized for further improvement of foam glass production technology through the comprehensive utilization of cullet, slags, iron ore processing waste, and high-silica rocks.

The authors investigate the impact of magnesium oxide on the dynamics of crystallisation and structural-mechanical properties of foam glass in the system "glass mass – gas – crystallites". The authors have established by methods of thermodynamic modelling, scanning electron microscopy and energy dispersive microanalysis that the introduction of MgO induces the formation of MgFe2O4 and Mg-Ca-silicates, reducing the proportion of quartz by 18%. Optimisation of MgO concentration (7.5 wt%) provided an increase in bending strength up to 86.5 MPa and microhardness up to 7.2 GPa. A systematic approach to controlling the temperature conditions of synthesis allowed us to stabilise the dissipative structures of the melt and minimise internal stresses. The results confirm the possibility of directional control of crystallite morphology (50-200 nm) to create materials with predicted thermal insulation and mechanical characteristics, according to GOST 33949-2016.

Urban glass waste is a significant by-product of residential areas, while scrap carbon fiber is a prevalent industrial by-product. This study explores an innovative approach to valorize these materials by producing foam glass (FG) for versatile applications, particularly in construction. A key challenge in FG production is enhancing its properties to meet increasingly stringent application-specific standards. The properties of FG are intrinsically linked to its porous structure, which depends on factors such as the foaming process. The oxidation of carbon fibers at high temperatures can induce a foaming effect, creating a porous matrix in the glass. This research investigates the effect of powdered recycled carbon fiber (PRCF)—an alternative method for recovering waste carbon fiber as a foaming agent for FG. PRCF was added at concentrations of 0.5%, 1%, and 1.5% by mass relative to powdered waste glass. Increasing PRCF content enhanced foaming and improved porosity, with total porosity rising from 47.18% at 0.5% PRCF to 65.54% at 1.5% PRCF, accompanied by a 50% reduction in compressive strength and a 68% decrease in thermal conductivity. The results demonstrate the feasibility of large-scale FG production with enhanced properties, achieved without substantial additional investment and by recovering two waste materials. This process supports sustainable development by promoting waste valorization and advancing circular economy principles.

In the present study, we have developed foam glass based on a waste glass of the SiO2- Na2O-CaO vitreous system, using calcium carbonate (CaCO3) which is a natural porogen very abundant in nature, 1% of which ensures the formation of a homogeneous porous structure, formed thanks to its decomposition during sintering process at 800°C. Graphite is introduced into the raw material matrix by substituting 0, 3, 9, and 15 wt% of the waste glass. To analyze the performance of the foam glass obtained, we measured several properties such as density, porosity, coefficient of absorption, reflection, and transmission of electromagnetic waves. The results clearly show that graphite has no remarkable effect on the properties of materials up to 15 wt%. Beyond this, the substitution has a significant effect on density (increasing from 0.225 to 0.64 g/cm3 ), porosity (decreasing from 91.01 to 73.59 %), and electromagnetic wave Absorption, which improves from 20 % for the sample with 0 wt % graphite (G1) to 91.37 % for the sample with 15 wt % graphite (G2).

Abstract The research of the Department of Railway Engineering and Track Management (DRETM) has long been focused on evaluating the potential application of various thermal insulating, reinforcing, or composite building materials in the construction of the sub-ballast layers. For this purpose, an experimental facility called the DRETM Test Stand was built on the campus of the University of Žilina (UNIZA), consisting of eight measurement profiles (test fields). Each measurement profile is characterized by its specific construction and material composition. The application of construction materials that have not yet been applied within the Slovak Railways network, such as extruded polystyrene, Liapor, Liapor concrete, foam concrete, and foam glass, is mainly evaluated within the individual measurement profiles. At the request of MACCAFERRI CENTRAL EUROPE, s.r.o., the drainage geocomposite MacDrain® W1071 was tested on the aforementioned test stand to assess its potential application in the sub-ballast layers. This drainage geocomposite is primarily designed to ensure drainage and separation functions within the construction of the sub-ballast layers. The article evaluates its potential use as a thermal layer to potentially increase the thermal resistance of the trackbed construction. In other words, it considers whether its application could enhance the protection of the subgrade surface of fine-grained soils not only against the adverse effects of water but also against frost.

Composite materials have found extensive applications in aerospace and other fields. Nevertheless, within these materials, invisible defects such as bubbles (air delamination), holes, and inclusions often emerge. These defects not only degrade the material’s performance but also pose significant safety hazards. As a result, it becomes essential to employ nondestructive testing (ndt) technology to detect and assess damage in composite materials. Currently, terahertz (thz) imaging has garnered substantial attention on account of its remarkable penetration ability and high resolution. In this paper, we propose a high-resolution tomography method based on thz time-domain spectroscopy technology. This method is applied for the first time to detect the actual and unknown defects in glass fiber pipes and foam core products, aiming to verify its effectiveness and practicality. The proposed method has achieved notable success in detecting genuine bubble and hole defects that elude detection by ultrasonic c-scan imaging, which is commonly used in industrial testing.

Sustainable structural lightweight concrete containing foam glass aggregates

This paper deals with heat transfer inside cellular solids (foamed glass insulation) under thermal shock and the impact of transient temperature fields on the local integrity (strength) of the structure. The Finite Element model of a three-dimensional regular, periodic structure of the foamed glass for thermal and structural analyses was built. Simulations of transient heat transfer and its effect on the stress distribution were carried out. This paper describes the main heat transfer mechanisms through the foamed glass structure. Essential factors which impact stress distribution within the structure have been identified: rapid thermal expansion effects within thermal shock, the gas pressure inside the structure of foamed glass and its change in transient heat transfer conditions. The residual gas pressure in foam glass was measured experimentally. The impact of this gas on heat transfer was evaluated. The conducted research allows for a better understanding of the behavior of closed-cell solid structures working in elevated temperatures, which allows for the design of more efficient and reliable thermal insulation systems using recycled materials for industrial applications.

In this study, we propose an optimized design using a honeycomb core coated with conductive material and nickel electroless plated glass fiber to enhance radar absorption performance in broadband and reduce radar cross-section (RCS) as a function of incidence angle, particularly for trailing edge geometry of aircraft wings. A honeycomb core coated with a conductive material displays propagation absorption performance through a conductive loss mechanism and multiple scattering. Its electromagnetic wave absorption characteristics were analyzed using coating resistance and thickness variables. The foam-based radar-absorbing sandwich composites comprised glass fiber/epoxy composite, polymethacrylimide (PMI) foam, and nickel-plated glass fiber/epoxy composite, and the design with optimized impedance and reflection coefficient through transmission line theory and genetic algorithm presented 90% wave absorption performance in a broadband frequency range. The field influence of HH and VV polarization was analyzed under high-angle incident electromagnetic wave conditions, revealing that the proposed wing trailing edge geometry radar absorber structure exhibits superior RCS performance. The results of this study indicate that the proposed wing trailing edge radar absorbing structure has the potential to significantly enhance RCS performance in complex geometries such as those found in aircraft wings.

Experimental studies of the fire extinguishing ability of systems based on bulk porous materials during acetone extinguishing were carried out. For this purpose, the experimental methodology for determining the fire extinguishing properties of such extinguishing agents, which was previously proposed for ethanol, was chosen. Crushed foam glass, granulated swollen perlite, and vermiculite were selected as bulk materials. As the bottom layer, which ensures the buoyancy of the fire extinguishing system, granular foam glass with a granule size of 10-15 mm was used. As the upper layer, which provides high insulating properties, we consider swollen perlite with a size of spherical granules with a diameter of 1-1.5 mm and swollen lamellar vermiculite with a linear size of 1×2 mm. The buoyancy of the selected bulk materials in acetone, their bulk density and moisture retention were experimentally determined. On the basis of the experimental results, the heights of the layers of dry and wetted bulk materials required for acetone extinguishing were calculated. It was found that the wetting of bulk materials leads to a significant increase in their extinguishing properties. This fact is explained by two factors: an increase in the insulating properties of perlite and vermiculite due to filling the voids between the perlite and vermiculite granules and a decrease in the concentration of acetone vapour due to its absorption by water. The introduction of water also increases the cooling properties of the fire extinguishing system. The lowest heights of fire extinguishing layers during acetone extinguishing are provided by the systems: wetted foam glass – 6.5 cm and foam glass (5.5 cm)+perlite (1 cm)+water. An expert evaluation of the complex parameter of the effectiveness of fire extinguishing agents for the selected fire extinguishing systems when extinguishing acetone was carried out. The best result was shown by wetted foam glass Further directions of research on the fire extinguishing characteristics of systems based on bulk porous materials and methods for establishing a complex parameter of the effectiveness of fire extinguishing agents are outlined.