Glass Addition Research Articles

Production of foamed glass-ceramics using furnace bottom ash and glass

This research has produced foamed glass-ceramics from coal fired power station furnace bottom ash (FBA) and soda-lime-silica glass. The as-received FBA was wet milled with different additions of glass. The resultant slurry was dried and formed into a powder. The powder was pressed and sintered at a range of temperatures with additions of a fluxing agent (sodium tetraborate decahydrate), a bubble stabilising additive (tri-sodium phosphate) and a bloating agent (calcium carbonate) and this produced foamed FBA-glass-ceramics. The effect of glass content and sintering temperature on the properties of the sintered ceramic foams are reported. A range of potential applications including thermal insulation and biological filters for water and wastewater treatment are discussed. The research demonstrates that it is possible to engineer the properties of FBA derived glass-ceramic foams by careful control of the composition and processing conditions in order to transform a problematic waste into commercially interesting materials.

Influence of red mud and waste glass on the microstructure, strength, and leaching behavior of bottom ash-based geopolymer composites

The influence of waste glass and red mud addition as alternative source of aluminosilicate precursors on the microstructural, mechanical, and leaching properties of bottom ash-based geopolymer was studied in this work through mineralogical, morphological, and spectroscopic analysis, as well as by conducting compressive strength and leaching tests. The bottom ash-based geopolymer composites were synthesized by adding a constant amount of waste glass (10% by weight) and increasing amounts of red mud (up to 30% by weight). The results derived from FTIR, 29Si and 27Al MAS NMR, and SEM–EDX revealed that adding up to 10% (by weight) red mud to the synthesis mixes leads to an increase in the degree of geopolymerization of the activated mixes. The compressive strength followed the same trend. An increase of more than 10% (by weight) red mud added to the synthesis mixes results in a significant decrease of compressive strength of the geopolymer composites. A low leachability of geopolymer composites in regard with their contaminants was revealed especially for those with good compressive strength.

Dielectric-temperature stability and breakdown strength of the Nb-doped 0.12BiAlO3-0.88BaTiO3 ceramics with B–Al–Si glass additive

[(0.12BiAlO3-0.88BaTiO3)+0.5 wt%Nb2O5]+x wt.% B–Al–Si glass ceramics (x = 0, 1, 2, and 4) were prepared by solid-state method. The effects of B–Al–Si glass additive on microstructural and electrical properties were investigated. After the adding of B–Al–Si glass, quartz appeared as a new impurity phase and the average grain size of the samples decreased (from 540 nm to 330 nm). All the samples satisfy the EIA X8R specification, meanwhile, the breakdown strength (BDS) increased (from 17 kV/mm to 29 kV/mm) with the rising glass content. The ratios of relaxation time of grain boundary to grain (τgb/τg) of the ceramics at 460 °C were calculated according to the complex impedance data. It is found that decreased value of τgb/τg suggests a weakened interfacial polarization effect after B–Al–Si glass addition, which is beneficial to the BDS performance of ceramics.

Feasibility of glass/basalt fiber reinforced seawater coral sand mortar for 3D printing

In remote islands and coastal areas, where there are no freshwater and river sand, the use of locally available seawater and marine sediments in mortar and concrete for building construction may be a better solution. Moreover, if there are no local materials for fabricating the formwork, 3D mortar/concrete printing may be considered. However, study on 3D printing using mortar/concrete made of seawater and marine sediments is still lacking. In this study, a series of mortar mixes made of seawater, coral sand, and glass or basalt fibers were produced to test their fresh and hardened properties for the purpose of developing 3D printable glass/basalt fiber reinforced seawater coral sand mortars. It was found that by adjusting the water reducer dosage, all the mortar mixes exhibited good buildability. The addition of glass or basalt fibers improved the flexural strength to some extent but slightly reduced the compressive strength. However, the flexural and compressive strengths of the printed specimens were significantly lower than those of the standard un-printed specimens. Overall, the fiber reinforced seawater coral sand mortar exhibits great potential to be applied as 3D printable cement-based material for use in remote areas.

THE INFLUENCE OF GLASS CONTAINING COMPONENT ON GYPSUM BINDER AND DRY MIX MORTAR PROPERTIES

The paper studies the properties of the gypsum binder after the addition of glass containing component (crushed granulated foam glass) and the suitability of the latter for the development of a new composition of the heat-insulated gypsum mixture.It is shown that the addition of the glass containing component (GCC) fraction of 0.14–1.25 mm in the amount of 5–15 % provides the highest strength increase of the gypsum binder. The presence of GCC fractions of 0.063–0.14 mm in the composition of the gypsum binder increases its softening coefficient from 0.42 to 0.48.The main properties of the gypsum mixture are studied after the addition of the GCC fraction of 0.063–4.0 mm in the amount of 30, 40 and 50 % of the binder mass. The initial setting of the GСС-containing mortar mixture occurs no later than in 6 minutes. The introduction of 50 % GCC significantly reduces the water retaining power to 85 %. An increase in the GСС content from 30 to 50 % in the composition of the gypsum mixture leads to a decrease in the thermal conductivity of the samples from 0.279 to 0.209 W/(m×°С). The compressive strength reduces from 15.85 to 9.273 MPa as the GСС content increases to 50 %. The adhesive strength to ceramic brick for compositions containing 30 and 40 % GСС ranges from 0.44 to 0.69 MPa.In relation to physical, mechanical and heat insulating properties, compositions containing 30 and 40 % of GСС are the most effective. These compositions can be modified by the addition of various setting retardants, water-retaining and plasticizing additives.

Research for modification of concrete with ash-containing waste of Dnistrovska PSPS (Ukraine)

The object of reseaerch is concrete samples modified with ash-containing fillers and plasticizers. As practice shows, the use of secondary resources is an important issue in the field of construction and entails significant savings. The issue is also considered from the point of view of environmental protection. The study is aimed at determining the effect of modification of concrete with ash-containing waste on the strength characteristics using the example of the hydroelectric power station of the Dnistrovska PSPS (Sokyriany district, Chernivtsi region, Ukraine). The main hypothesis of the study is the assumption that varying components such as fly ash, water glass, and superplasticizers will make it possible to obtain concrete with specified strength characteristics. To achieve the aim, the authors decided to use in the study the superplasticizer SikaPlast-520N and BETO-plast, Portland cement M400 and sands of the quarries of the Parkan and Suklei regions (Moldova). According to the plan of the experiment, studies of the influence of hardening conditions on the structure and properties of modified concrete samples were carried out. Destructive testing of samples was carried out in the laboratory directly on a hydraulic press.The results of experiments without the addition of liquid glass and the introduction of a minimum amount of fly ash and experiments with the introduction of a minimum amount of fly ash and the addition of 3 % water glass are presented. To determine the dynamics of strength gain, tests were carried out on 7, 14 and 28 days. The presented results of the study of the samples on day 7 show a gain of more than 50 % strength. This indicates the possibility of reducing the curing period of structural concrete in the formwork system. A more complete and objective idea of the quality of concrete is possible while taking into account the average strength of concrete and its homogeneity.Today, there is no unified theory that can relate the different properties of cement and filler to the final properties of a composite material. The issue of modifying concrete compositions when using fine aggregate from other quarries requires additional research. At the same time, the results of the experiment show that the use of microfillers based on wastes from the Dnistrovska PSPS provide ample opportunities not only for saving binders, but also for improving the physical, mechanical and operational characteristics of concrete.

An experimental analysis of the influence of electrolyte compositions, current density and duration of the micro­arc oxidation process on the structural­phase state and properties of VT3­1 titanium alloy

It was determined that in an electrolyte containing 1.75 g/L KOH+1 g/L Na2SiO3+2 g/L NaAlO2, with an increase in current density from 15 A/dm2 to 50 A/dm2, the phase composition of the coating changes. In the three-phase state (aluminum titanate, rutile, and amorphous-like phase), with increasing j, instead of an amorphous-like phase, a crystalline mullite phase appears. The hardness of the coating increases from 5400 MPa to 12500 MPa. It was found that, in combination with aluminum titanate, mullite is the basis for achieving high hardness in the coating. The formation of a ceramic micro-arc oxide coating on the surface of the VT3-1 titanium alloy makes it possible to reduce the dry friction coefficient by more than 5 times to f=0.09.The effect of electrolysis conditions during micro-arc oxidation of the VT3-1 alloy (titanium-based) on the growth kinetics, surface morphology, phase-structural state, and physical and mechanical characteristics (hardness, coefficient of friction) of oxide coatings was studied. It was found that the process in the mode of micro-arc discharges is stably implemented on the VT3-1 alloy in an alkaline (KOH) electrolyte with additions of sodium aluminate (NaAlO2) and liquid glass (Na2SiO3). This makes it possible to obtain coatings up to 250 μm thick. In this case, a linear dependence of the coating thickness on the time of the MAO process is observed. The growth rate of the coating increases with increasing current density. The highest growth rate was 1.13 μm/min. It was revealed that in an electrolyte containing 1 g/L KOH+14 g/L NaAlO2 with an increase in the duration of oxidation from 60 to 180 minutes, the relative content of the high-temperature phase, rutile, increases. In the coatings obtained in the electrolyte 1.75 g/L KOH+1 g/L Na2SiO3+2 g/L NaAlO2, with an increase in the duration of the MAO process, the relative content of the amorphous-like phase decreases and the content of the crystalline phase of mullite (3Al2O3·2SiO2) increases

Effect of hydroxyapatite and 45S5 bioactive glass addition on a dental adhesive resin cement

AbstractObjectiveThis study evaluates the mechanical, physical, and biological properties of resin‐based dental cement (RelyX ARC, 3M ESPE) incorporated with hydroxyapatite and 45S5 bioactive glass.MethodsBioactive glass (45S5) and hydroxyapatite (HA) were added to cement in different proportions (10 wt% and 20 wt%). Three‐point flexural strength, microhardness, surface roughness, film thickness, contact angle, and color were evaluated. Cytotoxicity in human osteoblasts culture (MG63) was evaluated. Statistical analysis was performed using one‐way and two‐way ANOVA and Tukey tests (α < 0.05).ResultsThe addition of HA and 45S5 bioactive glass reduced the flexural strength of the composite. However, the resistance value was greater than the minimum values of the ISO standard. Film thickness was below the maximum values, except for the 20% HA. The contact angle was constant at 24 hours and 14 days, except for 10% 45S5 group, which presented a significant decrease in mean contact angle. Cellular viability for all groups increased from the first to the 14th day. Additionally, the cellular viability was above 50%.ConclusionsIn vitro incorporation of 45S5 bioactive glass on resin cement resulted in a promising luting dental material with adequate mechanical properties, thin film thickness, improved wettability, and adequate biocompatibility.

Assessment of fiber distribution characteristics in the hybrid fiber reinforced concrete – An experimental study

Assessment of fiber distribution characteristics is critical in the determination of the mechanical properties of the Fiber Reinforced Concrete (FRC). In this study an experimental investigation was carried out to ascertain the Fiber distribution characteristics (Fiber dispersion coefficient and Fiber orientation factor) of the M30 grade Mono Glass FRC (MGFRC), Mono Steel FRC (MSFRC), Graded FRC (GrFRC), Hybrid FRC (HyFRC) and Hybrid Graded FRC (HyGrFRC). Two lengths of glass fibers and two lengths of steel fibers were blended into the concrete to obtain MGFRC, MSFRC, GrFRC, HyFRC, and HyGrFRC mixes. An image analysis technique using an optical microscope was used to determine the dispersion coefficient and orientation factor of all the mixes, as mentioned earlier. Effect of fiber length, fiber type and fiber grading on the fiber distribution characteristics of the FRC mixes were discussed. The fiber distribution characteristics were improved by the addition of glass and steel fibers, where glass fibers enhance the dispersion coefficient, and steel fibers enhance the orientation factor. Graded FRC specimens exhibited better fiber distribution than Mono FRC specimens. HyGrFRC specimens showed better fiber distribution characteristics when compared to HyFRC specimens, and this may be due to the more uniform distribution of fibers without clumping in HyGrFRC mixes due to the grading of fibers. From this study, it can be inferred that the blending of graded glass and graded steel fibers in a hybrid form into the concrete have shown a remarkable enhancement in the fiber distribution characteristics.

Microstructural and Dielectric Responses of Calcium Copper Titanate Added Soda-Lime Glass for High Frequency Devices

The microstructures and dielectric responses of calcium copper titanate (CCTO) ceramics with soda-lime glass addition was investigated. The addition of soda lime glass was varied from 0-5 wt.% by solid-state reaction. The dielectric properties of CCTO indicated that dielectric constant was increased while dielectric loss was decreased after glass addition. The SEM micrographs showed the grain size of CCTO was decreased while the grain boundaries area of CuO + glass were increased after the addition of soda-lime glass. Both XRD patterns of CCTO and CCTO-soda lime glass sintered samples showed the formation of CCTO phase with minor peaks of CuO phase, respectively. These results indicated that soda-lime glass addition gave a significant effect on the microstructural and dielectric responses of CCTO ceramics.

OBTAINING OF HYDRO-INSULATION MATERIALS, PENETRANTS AND OTHER DEFICIENT LOW- TONNAGE PRODUCTS FROM PETROLEUM


 
 
 
 Hydro-insulation of building constructions, different purpose structures is one of the most important and urgent problems of the present day. Currently concrete, ferroconcrete, metal and wooden materials are used for this purpose. Materials of this kind are not produced in the South Caucasian region. Their import, transportation, clearance by the customs and other expenses significantly increase the cost of buildings and makes it unprofitable to use them. Excreted from petroleum products – paraffins and cerezines, petrolatum, luminophores and various purpose binders, can become profitable basis for obtaining of moderm hydroinsulation materials. Their inclusion in modern hydroinsulation compositions will help to increase quality of these materials and to decrease their cost. By mixing of the goudron obtained as a result of rectification of oil pipeline sediments with milled secondary tyre casting, liquid glass, quarz sand and several additives – new hydroinsulation material was obtained.
 
 
 

3D mesoporous bioactive glass/silk/chitosan scaffolds and their compatibility with human adipose‐derived stromal cells

AbstractHuman adipose‐derived stem/stromal cells (hASCs) have been popularly studied as cell‐based therapy in the field of regenerative medicine due to their ability to differentiate into several cell types. In this study, in order to improve the mechanical strength and bioactivity of scaffolds for bone tissue engineering, three types of mesoporous bioactive glasses with different shapes and compositions were dispersed in the silk fibroin/chitosan (SF/CS)‐based scaffolds, which were fabricated with a combination of freezing and lyophilization. The characteristic and physical properties of these composite scaffolds were evaluated. The biocompatibility was also assessed through hASCs in vitro tests. Both Alamar Blue® and Live/Dead assay® revealed that the spherical mesoporous bioactive glass doped scaffolds enhanced cell viability and proliferation. Furthermore, the addition of spherical mesoporous bioactive glass into SF/CS scaffolds encouraged hASC osteogenic differentiation as well. These results suggested that this composite scaffold can be applicable material for bone regeneration.

Characterisation and disposability assessment of multi-waste stream in-container vitrified products for higher activity radioactive waste

Materials from GeoMelt® In-Container Vitrification (ICV)™ of simulant UK nuclear wastes were characterised to understand the partitioning of elements, including inactive surrogates for radionuclide species of interest, within the heterogeneous products. Aqueous durability analysis was performed to assess the potential disposability of the resulting wasteforms. The vitrification trial aimed to immobilise a variety of simulant legacy waste streams representative of decommissioning operations in the UK, including plutonium contaminated material, Magnox sludges and ion-exchange materials, which were vitrified upon the addition of glass forming additives. Two trials with different wastes were characterised, with the resultant vitreous wasteforms comprising olivine and pyroxene crystalline minerals within glassy matrices. Plutonium surrogate elements were immobilised within the glassy fraction rather than partitioning into crystalline phases. All vitrified products exhibited comparable or improved durability to existing UK high level waste vitrified nuclear wasteforms over a 28 day period.

Long-Term Behavior and Durability of Alkali-Activated Clay Mortars.

The need to increase the durability of clay-based materials, due to their inherent low strength and vulnerability in contact with water, led researchers to examine different options. In this paper, clay mortars were produced using four different activating solutions. Alkali hydroxides, alkali carbonates, and alkali silicates activating solutions were used. Interest is given to long term properties while their behavior to wetting–drying and freeze–thaw cycles is recorded. In total, the results of the experiments indicated the positive effect of the potassium metasilicate on mechanical characteristics presenting, however, low performance at wetting–drying. The combination of sodium metasilicate with sodium hydroxide solution has also presented a positive effect on both mechanical and physical properties. In contrast, sodium carbonate acted better in enhancing physical properties and granting water-resistant abilities. Moreover, the performance of the specimens mixed with water–glass addition presented excellent volume stability and low mass loss in durability tests.

Glass-Ceramic Foams from Alkali-Activated Vitrified Bottom Ash and Waste Glasses

Both vitrified bottom ashes (VBAs) and waste glasses are forms of inorganic waste material that are widely landfilled, despite having some economic potential. Building on previous studies, we prepared glass-ceramic foams by the combination of VBA with either soda-lime glass (SLG) or borosilicate glass (BSG). Suspensions of fine powders in weakly alkaline solution underwent gelation, followed by frothing at nearly room temperature. Hardened “green” foams were sintered, with concurrent crystallization, at 850–1000 °C. All foams were highly porous (>70%), with mostly open porosity. The glass addition was fundamental in both gelation (promoting the formation of carbonate and silicate hydrated phases) and firing steps. While SLG addition enhanced the viscous flow sintering, without a significant impact on the crystallization of gehlenite, the main crystalline phase from the devitrification of VBA, BSG addition caused a reactive sintering, with remarkable changes in the phase assemblage. The glass addition generally also allowed lower sintering temperatures and yielded products with excellent crushing strength. However, only specific conditions resulted in the complete immobilization of pollutants (e.g., Cr3+ ions).

An in vitro assessment of the physical properties of manually- mixed and encapsulated glass-ionomer cements

ObjectivesThe last decade has seen a variety of modifications of glass-ionomer cements (GICs), such as inclusion of bioactive glass particles and dispensing systems. Hence, the aim was to systematically evaluate effect of mixing modes and presence of reactive glass additives on the physical properties of several GICs.Materials and methodsThe physical properties of eight commercial restorative GICs; Fuji IX GP Extra (C&H), KetacTM Fill Plus Applicap (C&H), Fuji II LC (C&H), Glass Carbomer Cement and Equia® Forte Fil, capsulated versus manually mixed were assessed. 256 cylindrical specimens were prepared for compressive strength and microhardness, whilst 128 disc-shaped specimens were prepared for biaxial flexural strength tests. Fluid uptake and fluoride release were assessed. Data were analysed using one-way ANOVA and Games-Howell post-hoc tests (alpha = 0.05).ResultsBoth encapsulated GIC/RMGICs exhibited significantly improved mechanical properties in comparison to manually mixed equivalents, which in turn showed higher fluid uptake and early fluoride release (p < 0.05). The glass carbomer cement exhibited improved mechanical properties post ageing and evidence of mineral deposits were apparent in the microstructure.ConclusionsThe mixing mode and inclusion of reactive glass additives in cements had a statistically significant effect on physical properties of the selected GICs-RMGICs.

Production of a novel poly(ɛ-caprolactone)-methylcellulose electrospun wound dressing by incorporating bioactive glass and Manuka honey.

Wound dressings produced by electrospinning exhibit a fibrous structure close to the one of the extracellular matrix of the skin. In this article, electrospinning was used to fabricate fiber mats based on the well-known biopolymers poly(ɛ-caprolactone) (PCL) and methylcellulose (MC) using benign solvents. The blend fiber mats were cross-linked using Manuka honey and additionally used as a biodegradable platform to deliver bioactive glass particles. It was hypothesized that a dual therapeutic effect can be achieved by combining Manuka honey and bioactive glass. Morphological and chemical examinations confirmed the successful production of submicrometric PCL-MC fiber mats containing Manuka honey and bioactive glass particles. The multifunctional fiber mats exhibited improved wettability and suitable mechanical properties (ultimate tensile strength of 3-5 MPa). By performing dissolution tests using simulated body fluid, the improved bioactivity of the fiber mats by the addition of bioactive glass was confirmed. Additionally, cell biology tests using human dermal fibroblasts and human keratinocytes-like HaCaT cells showed the potential of the fabricated composite fiber mats to be used as wound dressing, specially due to the ability to support wound closure influenced by the presence of bioactive glass. Moreover, based on the results of the antibacterial tests, it is apparent that an optimization of the electrospun fiber mats is required to develop suitable wound dressing for the treatment of infected wounds.

Effect of Waste Glass Addition as a Replacement for Fine Aggregate on Properties of Mortar.

A responsible approach towards sustainable development requires the use of environmentally friendly, low-carbon, and energy-intensive materials. One positive way is to use glass waste as a replacement for fine natural aggregate. For this purpose, the effects of adding glass cullet to the mechanical properties of mortar were carried out. The glass aggregate made from recycled post-consumer waste glass (food, medicine, and cosmetics packaging, including mostly bottles), were used. This experimental work included four different contents of fine glass cullet (5, 10, 15, and 20 wt.% of fine aggregate). The compressive, flexural, and split tensile strengths were evaluated. Moreover, the modulus of elasticity and Poisson coefficient were determined. The addition of glass sand aggregate increases the mechanical properties of mortar. When comparing the strength, the obtained improvement in split tensile strength was the least affected. The obtained effect for the increased analysed properties of the glass sand aggregate content has been rarely reported. Moreover, it was determined that by increasing the recycled glass sand aggregate content, the density of mortar decreased. In addition, the relationships between the properties for mortar containing glass sand aggregate were observed.

Assessing the modification efficiency of waste glass powder in hydraulic construction materials

In this paper, the effects of waste glass powder on reaction kinetics, gel characteristics, as well as workability and mechanical property of two typical binding systems: Portland cement system and alkali activation system, are investigated. The commercial silica fume was used as a comparative supplementary cementitious material. The results show that waste glass incorporation improves the workability, while silica fume presents an obvious negative effect. Both waste glass powder and silica fume delay the early age reaction to some degree, but the reduction is less significant for waste glass. The addition of waste glass shows limited effect on the typical gel structure in Portland cement system; while in alkali activated system, silica fume incorporation results in more polymerized Si–O structure than waste glass. Thermal analysis indicates that waste glass powder exhibits relatively lower reactivity than silica fume in Portland cement system, but very similar reactivity in alkali activated system. Mixes containing waste glass show comparable but slightly lower compressive strength than the ones with silica fume addition, but a better balance between performance and cost is achieved. The microstructure characterizations further confirm the beneficial effect of waste glass powder in producing cementitious binding materials.

Densification Behavior, Microstructure, and Property of ZnO with Multi-Oxides Glass Addition at Different Sintering Temperatures

Zinc Oxide (ZnO) mixed with various amount of glasses were sintered at different temperatures. The densification behavior of zinc oxide with glass addition and its microstructure and dielectric constant sintered from 900° to 1200°C have been investigated. A unique glass composition contained GeO2, MoO3, and V2O5 (GMV) was designed to act as the sintering aid to enhance the densification and to adjust the dielectric constant of ZnO. The effect of sintering temperature on the densification behavior and dielectrics properties of ZnO was investigated by dilatometer, x-ray diffractometer, scanning electron microscopy and LCR meter. The glass additive formed a thin continuous liquid phase and rearranged ZnO particles into a dense microstructure at relatively low temperature. The dielectric constants of glass added ZnO ceramics were found to vary with the glass concentration and sintering temperature.