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The work was devoted to the study of the recycling of household glass waste by the electric pulse method. Cullet and glass containers were considered as the object of research. Cullet and used glass containers are considered suitable for recycling among solid household waste. The treatment of solid household waste was carried out with the formation of electrical discharges in an inhomogeneous environment (glass fragments and glass products in an aqueous environment). The experiments were carried out at different values of pulse discharge voltage (from 12 kV to 37 kV), capacitor bank capacity (from 0.4 to 1.2 µF), number of pulse discharges (from 250 to 1,000) and frequency (from 0.3 Hz to 2 Hz). The dependence of the output of the finished product on the parameters of electric pulse discharges has been revealed from the research results. According to the main results of the research work, it was found that as the parameters of electric pulse discharges increase, the yield of the finished product increases. The data made it possible to assign effective parameters for processing cullet and glass products using the electric pulse method. The granulometric composition of the powder material obtained by this method has been determined. A product with a diameter of the largest fraction of 5-8 mm and a diameter of a small fraction of 0.4 mm and 0.7 mm was obtained. The results of the experiment can be used in research on saving natural resources, energy conservation and solving environmental problems of solid waste recycling. Powdered glass is used as a thermal insulator and decorative material in construction. In addition, crushed glass is used in the production of concrete as an additional raw material. [ABSTRACT FROM AUTHOR]

Optical fiber with YPO4:Pr3+ nanocrystals (NCs) is presented for the first time using the glass powder—NCs doping method. The method's advantage is separate preparation of NCs and glass to preserve luminescent and optical properties of NCs once they are incorporated into optical fiber. The YPO4:Pr3+ nanocrystals were synthesized by the co-precipitation and hydrothermal methods, optimized for size (< 100 nm), shape, Pr3+ ions concentration (0.2 mol%), and emission lifetime. The core glass was selected from the non-silica P2O5-containing system with refractive index (n = 1.788) close to the NCs (no = 1.657, ne = 1.838). Optical fiber was drawn by modified powder-in-tube method after pre-sintering of glass powder—YPO4:Pr3+ (wt 3%) mixture to form optical fiber preform. Luminescent properties of YPO4:Pr3+ and optical fiber showed their excellent agreement, including sharp Pr3+ emission at 600 nm (1D2–3H4) and 1D2 level lifetime (τ = 156 ± 5 µs) under 488 nm excitation. The distribution of the YPO4:Pr3+ NCs in optical fiber were analyzed by TEM-EDS in the core region (FIB-SEM-prepared). The successful usage of glass powder—NCs doping method was discussed in the aspect of promising properties of the first YPO4:Pr3+ doped optical fiber as a new way to develop active materials for lasing applications, among others. [ABSTRACT FROM AUTHOR]

The emergent secondary phases and surface altered layer (SAL) during the aqueous corrosion of borosilicate glass have a great impact on its chemical durability. However, the formation and evolution of these structures are still unclear. Here, by studying the borosilicate glass altered at 90 °C in pore water, the water in pore space between glass powders, the formation of secondary phases could follow two ways: 1. the consumption of aqueous ions forms analcime, zeolite, calcium silicate and barite at the surface of glass; 2. the reorganization of silica aggregates leads to smectite within the SAL. Small-angle X-ray scattering and cross-sectional scanning electron microscopy results show that the release of soluble elements and the formation of smectite within the SAL significantly increase the porosity of SAL. Furthermore, the layer containing smectite reorganizes inwardly and the crystallinity of smectite is gradually increased over time. The observations of transmission electron microscopy reveal that the dissolution of glass potentially goes through an interface-coupled dissolution-reprecipitation process. [ABSTRACT FROM AUTHOR]

In Ethiopia, scraps of high-density polyethylene (HDPE) pipes and crushed glass bottles are largely considered waste and are not being recycled or reused. In this study, it is aimed at experimentally processing HDPE scrap and mixing it with waste glass powder to produce a composite material with the potential to become a matrix and reinforcement material for pipes. Six samples were produced with varying percentages of the reinforcement and matrix. Their mechanical and physical properties were measured according to composite standards. The compounding mechanism and chemical reactions were properly performed for each sample and crosslinking between all materials was characterized. The theoretical density of the samples was determined using the rule of mixture. After conducting all experiments, a composite sample with 27.645 MPa of tensile strength, 22.061 MPa of tear strength, an increase in hardness, an average actual density of 1.1195 g/cm3 and an increase in abrasion resistance capability was selected. This study demonstrates the potential for recycling HDPE scraps and waste glass powder into a composite material with desirable mechanical and physical properties for use in the production of pipes. The experimental results indicate that the waste HDPE and glass powder can be effectively processed and utilized as a cost-effective and sustainable alternative to virgin materials for the production of composite materials. The use of waste materials in this manner can not only reduce the environmental impact of industrial waste but also create new opportunities for the recycling and repurposing of waste materials. Furthermore, the resulting composite material can offer improved mechanical properties such as tensile strength, tear strength and abrasion resistance, compared to traditional materials. This study provides valuable insights into the development of sustainable composite materials and offers a promising avenue for future research on the recycling and reuse of waste materials. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of an experimental borosilicate glass on the mechanical and optical behavior of 5Y-PSZ zirconia and comparing it to commercial glaze and as-sintered. Disc-shaped specimens of a 5Y-PSZ (Zpex Smile) were prepared and sintered (1550 °C, 2 h). The zirconia discs were randomly divided according to the surface treatment: as-sintered (C), commercial glaze (G), and experimental borosilicate glass (SL). Glaze and experimental glass powders were mixed with building liquids and applied to zirconia with a brush. G specimens were fired at 950 °C and SL at 1200 °C. An extended dwell time of 20 min was applied to both groups. Biaxial flexural strength, roughness (Ra and Rz), translucency (TP 00), color alteration (ΔE 00), Vickers hardness, fracture toughness, residual stresses, and x-ray diffraction analyses were conducted. Statistical analyses were performed with Weibull statistics, Kruskal-Wallis, or ANOVA tests (α = 5%). SL yielded the highest flexural strength (799.35 MPa), followed by G (662.34 MPa), and C (485.38 MPa). The fracture origin of SL specimens was in the bulk zirconia, while G and C showed fractures starting at the surface. As-sintered reached the highest fracture toughness and hardness. Glaze and borosilicate glass provided surface compressive stresses. Borosilicate glass application led to phase transformation (t→m). SL and G showed the lowest roughness. TP 00 and ΔE 00 were similar among groups. Borosilicate glass improved strength without harming the optical properties of third-generation zirconia. Toughness and roughness provided by the experimental glass were similar to those from commercial glaze. • Experimental borosilicate glass improved the flexural strength of 5Y-PSZ. • Borosilicate glass application led to phase transformation (t→m) of 5Y-PSZ. • Glaze and borosilicate glass produced similar translucency and color alteration. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the mechanical properties and ion release from a commercially available resin-modified glass ionomer cement to a formulation reinforced by the addition of short glass fibres at various percentages. Methods: Three experimental groups were prepared by adding a mass ratio of 10%, 15% and 20% of short glass fibres to the powder portion of the cement from a capsule (GC Fuji II LC), while the control group contained no fibres. Microhardness (n = 12), fracture toughness, and flexural, compressive and diametral tensile strength (n = 8) were evaluated. To study ion release, readings were obtained utilising fluoro-selective and calcium-selective electrodes after 24 h, 7 days and 30 days (n = 12). The spatial distribution of fibres within the material was evaluated through scanning electron microscopy. The data were analysed using one-way ANOVA with a Bonferroni adjustment. Results: The findings suggest that elevating fibre weight ratios to 20 wt% results in improved mechanical properties (p < 0.05) in microhardness, flexural strength, diametral tensile strength and fracture toughness. In terms of ion release, a statistically significant difference (p < 0.001) was observed between the groups at the conclusion of 24 h and 7 days, when the fluoride release was much higher in the control group. However, after 30 days, no significant distinction among the groups was identified (p > 0.05). Regarding calcium release, no statistically significant differences were observed among the groups at any of the evaluated time points (p > 0.05). SEM showed the fibres were homogeneously incorporated into the cement in all experimental groups. Conclusions: Resin-modified glass ionomer enhanced with short glass fibres at a weight loading of 20% showcased the most favourable mechanical properties while concurrently maintaining the ability to release fluoride and calcium after a 30-day period. [ABSTRACT FROM AUTHOR]

Although experimental research demonstrates the feasibility of processing glass via selective laser melting (SLM), achieving SLM precision manufacturing of fused silica is still a challenging but promising field. Therefore, a numerical model was developed in this work to predict the densification kinetics of glass powder monolayer under SLM, which provided a simulation tool for the optimization design of processing parameters. To be particular, the relative neck diameter and density of the powder bed under SLM were calculated using a cluster model to simulate the degree of consolidation, from which the thermal diffusivity of the powder bed was determined and the corresponding results of heat transfer were obtained through the numerical model implemented by using finite difference method (FDM). The experimental results for the SLM of glass with different processing parameters from other references validated the simulation results with a prediction error of less than 2%. Hence, the effects of processing settings, such as the influence of particle size and preheating temperature, could be accurately investigated by using this numerical modelling method. It was found that using powders with smaller particle sizes and setting a higher preheat temperature could improve the manufacturing quality of the obtained glass parts. From the densification results of the numerical modelling, we also introduced a novel optimization criterion, which could be utilized to optimise the processing parameters and fabricate the high-purity glass parts via SLM. [ABSTRACT FROM AUTHOR]

In this study, trivalent rare-earth ion (Eu3+, Gd3+, and Yb3+)-substituted silicate-based bioactive glass scaffolds were prepared by robocasting method using sol–gel-derived bioactive glass powders for tissue engineering applications and cancer therapy. The structural, morphological, and mechanical properties of the prepared scaffolds as well as their in vitro bioactivity in simulated body fluid (SBF) were investigated in detail. In addition, an anticancer drug (5-FU) adsorption and release behavior of the scaffolds was studied as a function of time. In vitro, cytotoxicity and alkaline phosphatase activity were investigated using human skin fibroblast BJ and osteosarcoma SaOS-2 cells. Results showed that using lanthanide ion-containing (0.5, 1, 3, and 5 wt%) sol–gel-derived bioactive glass powders it was possible to successfully fabricate periodic, mesh-like patterned robocast glass scaffolds. All of the scaffolds prepared in the study sintered at 675 °C showed an amorphous structure. The compressive strength of scaffolds was in the range of 8.8 MPa to 13.6 MPa and the highest strength values were obtained in the Yb3+-containing scaffolds. Hydroxyapatite formation was obtained for the scaffolds immersed in SBF for 28 days. The fluorouracil adsorption amount was calculated to be ~ 25% for all types of scaffolds and the cumulative drug release was in the range of 20–25% depending on the dopant concentration. Results of the in vitro cell culture experiments revealed that all of the scaffolds fabricated in the study were not cytotoxic to fibroblast and osteosarcoma cells for up to 7 days under in vitro conditions. An increase was obtained for the ALP activities for both types of cells as the incubation time was increased. [ABSTRACT FROM AUTHOR]

The main objective of this paper research is a comparative study on the effect of the glass powder (GP) substitute from collected and recycled glass waste, as a fine partial cement replacement on the mechanical performance and durability of high performance concrete (HPC) and ordinary concrete (OC). For this two cement dosing were used of 400 kg/m3 to formulate OC and 450 kg/m3 to formulate HPC, and GP as considered binder like cement and not as fine addition, hence binder represent the sum of cement with GP (L=C+GP) with which will be made our two concretes formulation. Two ratios were used for the Water/Binder (W/B), the first W/B=0.35 for the HPC and the second W/B=0.5 for the OC, this ration is very important to fix the concentration of superplasticizer. A percentage of 10% and 20% substitution of cement CPA without additions noted CEM I 52.5 by the glass powder with fineness of 3600 cm 2/g are used. The evaluation of the compressive strength was followed from 7 to 365 days in order to study the behavior of the GP at different ages affected by the cement dosing and the ratio W/B compared to the reference concrete without GP for the two concretes HPC and OC. At 28 days the strengths of concretes with GP is affected by the replacement of a quantity of cement since the two reference concretes were superior but beyond this age an inverse behavior is noticed such that results obtained at age of 365 days seem to be advantageous in terms of savings in the quantity of cement used by interpreting the compressive strength, and the decrease in quantity of water in the mixtures offers a remarkable difference between the two concretes studied by using 20 % of GP as replacement of cement. [ABSTRACT FROM AUTHOR]

Biocomposite materials are widely implemented in various applications in clinical dentistry and orthopedics since it is possible to combine multiple materials by relying on their compatibility. Ceramic-based materials have osteogenic and osteoconductive features owing to their inorganic constituents with dental and bone tissue. β-tricalcium phosphate (β-TCP) and bioactive glass have excellent biocompatibility, bioresorbability, and bioactivity. In this study, β-TCP and BG powders were fabricated by spray pyrolysis (SP) and spray drying (SD). These fabrication methods are suitable for the mass production and synthesis of spherical particles. At first, β-TCP and BG spherical particles were synthesized by SP and characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electronic microscopy (SEM). After that, these powders were granulated with the different weight ratios of β-TCP/BG = 100/0, 75/25, 50/50, 25/75, and 0/100 by SD. The resulting granulation powders were characterized using XRD, FT-IR, and SEM to investigate phase compositions and microstructures. In addition, cytotoxicity was investigated using the MTT assay. [ABSTRACT FROM AUTHOR]

The challenge posed by weak soil, characterized by low bearing capacity and shear strength, is significant in civil engineering, impacting road construction, structural foundations, and irrigation systems. Recycling non-biodegradable waste, especially glass waste, presents a promising solution for environmental sustainability and cost-effectiveness in construction. This study aims to improve the geotechnical properties of weak soils by stabilizing them with Waste Glass Powder (WGP) and exploring novel construction applications. The experimental investigations determined the optimal incorporation of glass powder into soil samples, ranging from 2% to 10% by dry weight. Geotechnical tests, including sieving analysis, Atterberg limits determination, California Bearing Ratio (CBR) tests, and Unconfined Compressive Strength (UCS) assessments, were conducted to assess the effect of glass powder addition. At a 10% glass powder content, the Plasticity Limit (PL), Liquid Limit (LL), and Plasticity Index (PI) were 18.4%, 33.9%, and 15.5%, respectively. The addition of glass powder significantly improved CBR values, reaching peaks of 10.5% (soaked CBR) and 22.3% (unsoaked CBR). Moreover, UCS increased to 135.6 kN/m² with 8% glass powder, decreasing slightly to 120.8 kN/m² with 10% glass powder. These findings highlight waste glass as a viable additive for enhancing the engineering properties of weak soils, promoting sustainable construction practices. [ABSTRACT FROM AUTHOR]

This study aimed to develop accurate models for estimating the compressive strength (CS) of concrete using a combination of experimental testing and different machine learning (ML) approaches: baseline regression models, boosting model, bagging model, tree-based ensemble models, and average voting regression (VR). The research utilized an extensive experimental dataset with 14 input variables, including cement, limestone powder, fly ash, granulated glass blast furnace slag, silica fume, rice husk ash, marble powder, brick powder, coarse aggregate, fine aggregate, recycled coarse aggregate, water, superplasticizer, and voids in mineral aggregate. To evaluate the performance of each ML model, five metrics were used: mean absolute error (MAE), mean squared error (MSE), root mean squared error (RMSE), coefficient of determination (R2-score), and relative root mean squared error (RRMSE). The comparative analysis revealed that the VR model exhibited the highest effectiveness, displaying a strong correlation between actual and estimated outcomes. The boosting, bagging, and VR models achieved impressive R2-scores in the range of 86.69%–92.43%, with MAE ranging from 3.87 to 4.87, MSE from 21.74 to 38.37, RMSE from 4.66 to 4.87, and RRMSE between 8% and 11%. Particularly, the VR model outperformed all other models with the highest R2-score (92.43%) and the lowest error rate. The developed models demonstrated excellent generalization and prediction capabilities, providing valuable tools for practitioners, researchers, and designers to efficiently evaluate the CS of concrete. By mitigating environmental vulnerabilities and associated impacts, this research can significantly contribute to enhancing the quality and sustainability of concrete construction practices. [ABSTRACT FROM AUTHOR]

The use of waste as supplementary cementitious materials (SCMs) in concrete is already widespread, with glass waste being an increasingly used option. The utilization of glass waste as a partial substitute for cement in small proportions has shown satisfactory outcomes. Nevertheless, substituting cement in high proportions requires further investigation. Experimental research was carried out on the mechanical and durability properties of concrete with the replacement of cement by glass powder (GP), at a high volume equal to 50%. Binder content (cement plus GP) varied from 300 to 500 kg/m3. The results are promising regarding the use of the high volume of GP in high-performance concretes. The specimens with 500 kg/m3 of binder (50% of which was GP-G250) achieved almost 55 MPa at 28 days. The specimen with the lowest resistance was G150, with 32 MPa. This result may be related to the high pozzolanic activity index of the used GP. The specimens with GP showed satisfactory performance regarding chloride migration, with diffusion coefficients always below those of the reference specimens. The G250 concrete showed a reduction of 58%. Regarding open porosity, concretes with 50% GP had a lower porosity than the reference concretes. The smallest reduction (21%) occurred in the G150 concrete. The reduction in porosity provided by the fineness of the GP may be the main cause of this high performance. Concerning capillary absorption, the GP concretes have a reduction that varies between 47% for G150 and 67% for G250. This fact may be related to the existence of a larger quantity of larger-sized capillary pores in the reference concretes. [ABSTRACT FROM AUTHOR]

In this paper, an innovative infill wall is proposed and examined experimentally and parametrically. The proposed wall has an innovative design and is constructed with lightweight concrete strengthened by waste glass. The proposed wall not only demonstrates robust performance against out-of-plane loading, but also exhibits exceptional behavior under elevated temperatures. Additionally, the necessary equations used to predict the wall's behavior are also presented. The results reveal that glass powders affect weight loss. During the initial temperature application, ranging up to 600 °C, specimens with 0% and 8% glass powder experienced maximum and minimum weight loss, respectively. At 200 °C, glass powder concentrations below 4% caused a reduction in compressive strength, f c ′ , while concentrations between 4% and 8% led to an increase in f c ′ . Consequently, the optimal glass powder volume was determined to be 6% for specimens under varying temperature conditions. The out-of-plane loading tests indicated that although the wall was exposed to heat up to 800 °C, the resistance did not decrease significantly. Given its role as a non-load-bearing wall without the application of gravity, this innovative structure is anticipated to perform admirably in fire scenarios during seismic events. [ABSTRACT FROM AUTHOR]

Recycling economy and the re-utilization of solid waste have become important parts of sustainable development strategy. To improve the utilization rate of waste glass, glass powder high-strength cementitious material (GHSC) was prepared by replacing part of the cement in the cementitious material with ground waste glass powder. Firstly, the effect of glass powder particle size on the flexural and compressive strength of GHSC was investigated by the gray correlation method, and the optimal grinding time was obtained. Additionally, the effect of the magnitude of steam curing temperature and the length of steam curing time on the compressive strength and flexural strength of GHSC was investigated, and the mechanism of the effect of the curing regime on the strength was explored by examination of the microstructure. Finally, to simplify the curing process of GHSC, the effects of Ca(OH)2 and Na2SO4 as excitation agents on the compressive strength and flexural strength of GHSC at different dosing levels were compared. The results showed that glass powder with a particle size of less than 20 μm would improve the compressive strength and flexural strength of the specimen. Steam curing can significantly improve the flexural strength and compressive strength of GHSC specimens. At a steam curing temperature of 90 °C for a duration of three days, the compressive strength and flexural strength of GHSC increased by 76.7% and 98.2%, respectively, compared with the standard curing specimens. Ca(OH)2 and Na2SO4 as excitation agents significantly enhanced the compressive and flexural strengths of GHSC under standard curing conditions. [ABSTRACT FROM AUTHOR]

The Te-based glass powder exhibits distinctive characteristics such as a low melting temperature and high chemical stability, rendering it a focal point of research in the realm of glass powder applications for solar cells. In this investigation, a pioneering Ge-containing Te-based lead-free glass powder was synthesized, and the influence of GeO2 content on critical parameters such as glass transition temperature (Tg), high-temperature fluidity, high-temperature wettability, acid and alkali resistance, as well as the network structure of the glass, was systematically explored. At an optimal GeO2 content of 8%, the glass powder displayed the lowest Tg (437°C), accompanied by a subdued crystallization reaction. The high-temperature fluidity and wettability exhibited favorable characteristics, indicating that the inclusion of GeO2 in the glass powder resulted in an enhanced interface contact. Building upon this foundation, techniques to augment the Ag+ content within the glass powder were investigated, along with the interaction between Ag+ and the SiNx anti-reflection layer or silicon on the surface of crystalline silicon solar cells. It was discerned that the Ag+ content in the glass powder significantly influences the deposition of silver microcrystals on the surface of crystalline silicon, thereby impacting the contact resistance of the solar cell. Then influences the series resistance and photoelectric conversion efficiency of the solar cell. [ABSTRACT FROM AUTHOR]

The widespread use of flat electric heaters in equipment and household appliances requires the search for simpler and cheaper technologies for their production. This paper proposes a method for producing an electrically conductive coating (NiAl) and an electrically insulating layer (glass ceramics) in one stage: self-propagating high-temperature synthesis in a thermally coupled (Ni + Al)/(PbO2 + B + Al2O3 + glass) powder mixture. The combustion wave front propagation process is investigated, and the effect of layer thickness along with the ratio of the PbO2 + B + Al2O3 + glass powder mixture components on the wave front propagation velocity and the wave front temperature is described. It is revealed that the wave front of the exothermic process expands when a PbO2 + B mixture is added to the bottom layer. The addition of this mixture makes it possible to reduce the NiAl layer thickness and ensure the formation of a uniform dielectric coating. The phase composition and microstructure of the coating are studied. Optimal ratios are determined for layer thicknesses and the composition of the powder mixture of the layers. The fundamental possibility of forming an electrically conductive and dielectric coating by the method of self-propagating high-temperature synthesis in one stage is shown. [ABSTRACT FROM AUTHOR]

• Produced added-value glass-ceramics without using chemical additives. • Predicted the crystallisation behaviour of the glass-ceramics. • Anorthite was formed and transformed into wollastonite in glass-ceramics. • The incorporation of waste glass densified and refined the pore structure. Disposal of waste glass and incinerated sewage sludge ash (ISSA) in landfills is a waste of resources and poses significant environmental risks. This work aims to recycle waste glass and ISSA together to form value-added glass-ceramics. The physical and mechanical properties, leaching behaviour, and microstructure of the glass-ceramics produced with different proportions of waste glass powder (WGP) and ISSA were investigated. Thermodynamic calculations were performed to predict the formation of crystalline phases and the phase transformation involved. The results showed the potential of WGP and ISSA as raw materials in glass-ceramics production. WGP effectively densified the microstructure of the glass-ceramics by forming a viscous phase. As WGP content increased, the total porosity of glass-ceramics decreased whereas the density increased, accompanied by the formed anorthite transforming into wollastonite. The incorporation of WGP densified and refined the pore structure of the glass-ceramics, thereby improving the mechanical properties and reducing the water absorption. The glass-ceramics produced with a 50:50 blend of WGP and ISSA exhibited the highest compressive strength of 43.7 MPa and the lowest water absorption of 0.3 %. All fabricated glass-ceramics exhibited innocuous heavy metal leaching. The co-sintering of ISSA and WGP can produce additive-free glass-ceramics, characterized by reduced energy consumption and notable heavy metal immobilization capacity. These materials hold promise for utilization in construction as building materials. [ABSTRACT FROM AUTHOR]

Despite numerous studies conducted on the potential of waste materials as cement substitutes, the resistance of mortars comprising such blended cementitious materials against acidic environments has seldom been investigated. This paper presents an investigation into the potential of waste glass powder (WGP) as a replacement for cement in enhancing the mechanical, and durability of cementitious materials subjected to acidic environments. The study examines the impact of WGP on the resistance of mortar to hydrochloric acid solution attack, with specimens containing 0%, 5%, 10%, 15%, 20%, 25%, and 30% WGP produced as cement substitutes. The tests were conducted on the cement mortar and paste after water curing for 7, 14, 28, 42, and 56 days. Initially, the pozzolanic activity index assessment, fresh density, water absorption, and compressive strengths during water curing times were evaluated. Subsequently, the performance of mortars, when subjected to hydrochloric acid solutions, was assessed, including mass loss, residual compressive strength, visual inspection, and microstructure features during 8 weeks of immersion in hydrochloric acid. The results of the study indicated that the incorporation of WGP led to improved hydrochloric acid resistance in the mortar. Furthermore, an increase in WGP content resulted in a reduced reduction in compressive strength against hydrochloric acid attacks as the ages progressed. The study revealed that the mortar containing 5% WGP as a cement substitute had the highest compressive strength compared to other specimens, and using 10% WGP as a supplementary cementitious material was comparable to the control mixture. Finally, the x‐ray diffraction pattern indicated that the specimen containing 5% WGP had a lower intensity of portlandite peaks than the reference specimen. [ABSTRACT FROM AUTHOR]

Ultra-high-performance concrete (UHPC) is a high-tech concrete whose excellent mechanical and durability characteristics are ascribed to the homogeneity and high packing density of its matrix. However, due to the high contents of cement and silica fume usually necessaries for achieving this packing density, UHPC's final cost and carbon-footprint are far higher than standard concretes. Therefore, over the last few years, the spotlight of UHPC's research has focused sharply on the analysis of locally available supplementary cementitious materials as partial replacement of cement and silica fume. This article presents an investigation to analyze the effect of rice husk ash (RHA) as partial substitution of cement in a previously optimized mixture of recycled-glass-UHPC by means of several statistical tools. Cementitious materials employed in this research involved silica fume, limestone powder, recycled glass powder and ordinary Portland cement (OPC). Based on the results, it can be concluded that RHA addition in the optimized glass UPHC yields to a significant decrease in the workability of concrete and a slight decrease of compressive strength. Results also demonstrated the high interaction between the RHA and water contents, which could be ascribed to the water absorption and internal curing provided by RHA particles. [ABSTRACT FROM AUTHOR]

Laser‐driven phosphor‐converted white‐laser diodes are supposed to be next‐generation high‐brightness lighting sources for their unparalleled photoelectric efficiency and light quality, yet a significant obstacle hitherto has resided in the shortage and serious laser‐induced luminescence saturation of red emitters. Here, a hot‐pressing synthesis route to obtain high‐performance red‐emitting cordierite (Mg2Al4Si5O18:Eu2+) ceramic is developed, which enables the in situ formation of bulk specimens with high crystallinity (>90%) from the counterpart glass powders. A preeminent saturation threshold of 21 W mm−2 is realized in a red‐emitting Mg2Al4Si5O18:Eu2+ ceramic film converter. More importantly, the luminous exitance reaches 209 lm mm−2, which is 5 times that of commercial red phosphor‐converted‐LED, indicating breakthrough progress in the comprehensive light‐emitting performance of red converters. This work innovates the solid‐state synthesis of laser bulk converters from glass to meet the demanding requirements of advanced warm white laser lighting. [ABSTRACT FROM AUTHOR]

Glazed backplane glass is one of the most important assembling materials for photovoltaic module. The reflectivity of glazed backplane glass is related to the power generation efficiency of photovoltaic modules. The reflective coating of backplane glass is made of TiO2, glass powder, varnish and other glaze materials, and it is prepared via high-temperature calcination. Because TiO2 reserve is limited and expensive, the development of low-titanium coated backplane glass is one of the important methods to reduce the cost of photovoltaic modules. Therefore, low-titanium glazed backplane glass was synthesized by replacing TiO2 with low cost sub-titanium powder. The effect of the amount of sub-titanium powder on the reflectivity of backplane glass was studied. Acid resistance, alkali resistance, salt and boiling immersion of low-titanium glazed backplane glass were also investigated systematically. It was found that the low-titanium glazed backplane glass presented excellent tolerance similar as the glazed backplane glass. [ABSTRACT FROM AUTHOR]

Tissue engineering faces an intriguing challenge in creating biomaterials for cartilage repair. Within the category of biopolymeric scaffolds, hydrogels made from polysaccharides are particularly suitable for regenerating cartilage tissue. In this paper, a new formulation of biocompatible alginate-based hydrogel for joint cartilage regeneration was investigated. An alginate-dendrimer hydrogel obtained by covalently grafting alginate with polyamidoamine generation 5 dendrimer. 58S bioactive glass was synthesized through sol–gel procedures and was added to the hydrogel before cross-linking. The obtained hydrogel is an innovative system with sustained drug-releasing properties and improved mechanical behavior in comparison to the alginate matrix. For instance, the tensile and compressive modulus of the fabricated composite hydrogel increased from 0.035 to 0.072 MPa and 0.17 to 0.40 MPa respectively. Whereas the degradation ratio decreased from 0.26 to 0.09% by the addition of polyamidoamine and bioactive glass. The developed hydrogel also showed better properties in in-vitro studies such as swelling and degradation. MTT assay showed no toxicity and revealed the biocompatibility of prepared hydrogel. The MTT test, also performed better adhesion of cells by the addition of bioactive glass powder. The composite hydrogel loaded with tetracycline hydrochloride showed more sustained drug-release behavior and excellent antibacterial properties compared to bear alginate hydrogel. Therefore, the Alginate/polyamidoamine/bioactive glass hydrogel can couple the well-known bioactive properties of 58S bioactive glass with good biocompatibility of alginate-dendrimer hydrogels, opening new approaches in the field of tissue engineering. [ABSTRACT FROM AUTHOR]

The objective of this research is to find the optimal ratio of glass power (GP) and municipal incinerated bottom ash (MIBA) for producing environmentally friendly interlocking paving blocks. To achieve this, 15 different ratios of mortar samples, sized 5 × 5 × 5 cm, were produced using a 1:3 cement-to-aggregate ratio and a 0.5 water-to-cement ratio. GP was used to substitute cement at 0, 10, and 20% by weight, while MIBA was used to substitute aggregate at 0, 10, 20, 30, and 40% by volume. The samples were divided into two groups and cured with water for 28 and 90 days. Physical testing was performed on the mortar samples after curing. The results show that at 28 days of curing, BA10 and BA20 had compressive strengths of 42.28 and 40.92 MPa respectively, which is higher than the standard for interlocking concrete block (40 MPa) according to TIS 827-2531. At 90 days of curing, GP10BA10, BA10, GP10, GP10BA20, GP20, BA20, and BA30 had compressive strengths of 47.62, 43.63, 43.51, 43.48, 42.73, 42.40, and 40.40 MPa respectively, which also meets the TIS standards. [ABSTRACT FROM AUTHOR]

Utilizing waste materials in producing ultra-high-performance concrete (UHPC) represents a highly effective approach to creating environmentally sustainable concrete using renewable resources. This study focused on incorporating ground glass cullet (GP) at various replacement levels in UHPC production. Additionally, plastic bottle fibers (PBFs) were derived from discarded plastic bottles and employed in the mix. The replacement levels for GP spanned from 0% to 40%. Single-use plastic bottles were transformed into strip fibers, both with and without the inclusion of microsteel fibers, at varying contents of 1.1% and 2.2% (volume-based). A single-fiber test was conducted on PBFs under different strain rates. The introduction of optimal GP content had a profound positive iMPact on compressive strength. Incorporating 2.2% plastic strips induced strain hardening behavior, while further inclusion of microsteel fibers resulted in substantial enhancements in mechanical properties. Two types of microsteel fibers were employed, characterized by different aspect ratios of 65 and 100. The optimum GP content was identified as 10%. Moreover, the UHPC mix achieved superior compressive strength, exceeding 140 MPa when composed of 1.3% (volume-based) microsteel fibers with an aspect ratio of 65 and 2.2% PBF (volume-based). Notably, mixtures featuring microsteel fibers with a higher aspect ratio demonstrated the highest flexural strength, exceeding 8000 N in the presence of 2.2% PBF. Longer microsteel fibers exhibited adequate slip properties, facilitating strain transfer and achieving a strain-hardening response in conjunction with plastic bottle fibers. These findings illuminate the potential for harnessing hazardous waste materials to improve the performance and sustainability of UHPC formulations. [ABSTRACT FROM AUTHOR]

Using melt-derived LD glass powders and 5–20 M NaOH solutions, porous lithium disilicate (Li2Si2O5, LD) glass–ceramics were prepared by the cold sintering process (CSP) associated with the post-annealing technique. In this novel technique, H2O vapor originating from condensation reactions between residual Si–OH groups in cold-sintered LD glasses played the role of a foaming agent. With the increasing concentration of NaOH solutions, many more residual Si–OH groups appeared, and then rising trends in number as well as size were found for spherical pores formed in the resultant porous LD glass–ceramics. Correspondingly, the total porosities and average pore sizes varied from 25.6 ± 1.3% to 48.6 ± 1.9% and from 1.89 ± 0.68 μm to 13.40 ± 10.27 μm, respectively. Meanwhile, both the volume fractions and average aspect ratios of precipitated LD crystals within their pore walls presented progressively increasing tendencies, ranging from 55.75% to 76.85% and from 4.18 to 6.53, respectively. Young's modulus and the hardness of pore walls for resultant porous LD glass–ceramics presented remarkable enhancement from 56.9 ± 2.5 GPa to 79.1 ± 2.1 GPa and from 4.6 ± 0.9 GPa to 8.1 ± 0.8 GPa, whereas their biaxial flexural strengths dropped from 152.0 ± 6.8 MPa to 77.4 ± 5.4 MPa. Using H2O vapor as a foaming agent, this work reveals that CSP associated with the post-annealing technique is a feasible and eco-friendly methodology by which to prepare porous glass–ceramics. [ABSTRACT FROM AUTHOR]

Trace element diffusion is a powerful tracer of kinetic magmatic processes such as recharge and fluid exsolution. However, the dependence of diffusivities (D) on melt water contents is poorly quantified, and most trace element diffusivities were determined in water-free melts unrealistic for most natural magmatic systems. Here, we investigate the diffusion of the alkali trace elements Li, Rb, and Cs as a function of water content in rhyodacite, high-silica rhyolite, and peralkaline rhyolite. For the diffusion experiments, homogenous hydrous glass cylinders were produced from trace element-doped and undoped powdered glass with 1–8 wt% H 2 O. Glass cylinders with the same water content but different trace element concentrations were paired along polished contact surfaces. Diffusion experiments were conducted between 720 and 1100 °C at 100–700 MPa for 5–25 min using gas pressure vessels or a piston cylinder apparatus. Resulting diffusion profiles were analyzed by LA-ICPMS and evaluated by a Monte Carlo iterative fitting procedure for full error propagation. At a given experimental temperature, measured log 10 D values increase linearly with melt water content, with one order of magnitude increase for Li, two orders for Rb, and three orders for Cs from least hydrous (1 wt%) to wettest (8 wt%) experiment, due to a linear decrease in activation energies. Variations in major element composition only have a minor effect. We illustrate the impact of differential diffusion in hydrous silicic magmas on their trace element budget by coupling our data to a two-phase mechanical model of channelized fluid transport in magmatic systems. Quantifying water-dependent diffusivities provides an important tool to track the exsolution, mass and rate of fluid transport within long-lived shallow mushy magma reservoirs in the Earth's crust. [ABSTRACT FROM AUTHOR]

The antioxidant activity of Mn as additive in a 45S5 type glass system with and without P 2 O 5 was studied by mimicking the activity of catalase (CMA) and superoxide dismutase (SOD) enzymes. Glasses were melted either under oxidizing or reducing atmosphere (N 2 /H 2) to compare the processing influence on the Mn oxidation state. Thermal (DTA) and optical (UV–Vis) characterizations of the glass powders were carried out to obtain further insight into the structural role of Mn. A correlation of in vitro apatite formation between Tris buffer solution and Simulated Body Fluid (SBF) was performed to optimise Mn substitution, where a decrease in apatite formation was observed by increasing Mn content. Despite this, glasses with up to 1.0 mol% MnO did not show any delay in apatite formation and maintained their CMA and SOD activity. The antioxidant effect of Mn can be attributed to the interconversion Mn2+ ↔ Mn3+ occurring on the glass surface through a heterogeneous catalysis. P 2 O 5 plays an important role in the antioxidant effect of the glass, possibly by charge balancing Mn ions and forming more stable units compared to those formed with Ca and Na. The amount of Mn2+ is predominant in the glass network with respect to Mn3+ in all synthetized glasses. Moreover, glass melting in a reducing atmosphere further avoided Mn oxidation. [ABSTRACT FROM AUTHOR]

Dichromatic phosphor-in-glass films (PiFs) are recognized as ideal color converters for high-quality laser lighting, but photon reabsorption among multiple phosphor degrades the luminescence performance. Therefore, there is urgent to design a suitable PiF structure to alleviate this problem. Herein, the green-emitting phosphor YAGG:Ce and the orange-yellow-emitting phosphor GdYAG:Ce are mixed with silicate glass powder respectively, and print on the sapphire plate with high thermal conductivity (TC) to prepare spatially separated structure PiF (SS-YG PiF). Under the excitation of blue LD with power of 6.15 W, the luminous flux (LF) of SS-YG PiF reaches 1020.4 lm, and the corresponding luminous efficiency (LE) reaches 165.92 lm/W and CRI∼80. Notably, the perfect white light color coordinates (0.3354, 0.3253) are obtained at 6.15 W. In addition, SS-YG PiF has a lower surface temperature and a higher TC (9.89 W m−1K−1), reflecting the excellent luminescence performance and thermal properties of SS-YG PiF. [ABSTRACT FROM AUTHOR]

In order to promote the sustainable use of resources and reduce the waste of waste glass and tailings resources. The present study focuses on a fluorite mine as the research subject, utilizing coarse tailings, fine tailings, cement substitute-curing agent, and recycled waste glass as the primary raw materials. It investigates the changes in compressive strength of coarse tailing with varying sand- binder ratios and glass content at 3-day, 7-day, and 28-day intervals when the filling slurry concentration is set at 77% and the ratio of coarse tailings to fine tailings is maintained at 2:1. The findings indicate that there is minimal impact on the compressive strength of test blocks when using a sand binder ratio of 4:1 and a glass sand content below 10%. However, once the glass sand content exceeds 10%, a significant decline in compressive strength occurs. Scanning electron microscope (SEM) images reveal ettringite crystal formation in test blocks with both 0% and 25% glass sand content due to high levels of Na2O in the glass sand. This leads to internal expansion within test blocks resulting in reduced strength. Notably, when using a sand-binder ratio of 8:1 along with a glass sand content of 25%, early strength characteristics are observed for test blocks. Furthermore, incorporating glass sand has little influence on late-stage strength for backfill when employing either an 8:1 or 12:1 sand-binder ratio. Based on this experiment conducted under conditions including mass concentration of 77%, the optimal waste-glass-to-mine-tailings-filling-sand-binder-ratio is determined as 8:1with a corresponding glass content of 25%. [ABSTRACT FROM AUTHOR]

Cementitious composites' performance degrades in extreme conditions, making it more important to enhance its resilience. To further the adaptability of eco-friendly construction, waste materials are increasingly being repurposed. Cementitious composites deteriorate in both direct and indirect ways due to the facilitation of hostile ion transport by water. The effects of using eggshell and glass powder as partial substitutes for cement and sand in mortar on the water-absorption capacity were investigated using machine learning (ML) modeling techniques such as Gene Expression Programming (GEP) and Multi Expression Programming (MEP). To further assess the importance of inputs, sensitivity analysis and interaction research were carried out. The water absorption property of cementitious composites was precisely estimated by the generated ML models. It was noted that the MEP model, with an R2 of 0.90, and the GEP model, with an R2 of 0.88, accurately predicted results. The sensitivity analysis revealed that the absorption capacity of the mortar was most affected by the presence of eggshell powder, sand, and glass powder. GEP and MEP model's significance lies in the fact that they offer one-of-a-kind mathematical formulas that can be applied to the prediction of features in another database. The mathematical models resulting from this study can help scientists and engineers rapidly assess, enhance, and rationalize mixture proportioning. The built models can theoretically compute the water absorption of cement mortar made from eggshell powder and glass powder based on varied input parameters, resulting in cost and time savings. [ABSTRACT FROM AUTHOR]

The use of red mud in the geopolymer production is an attractive method for managing this waste. However, the processing steps usually applied, such as drying and grinding, can significantly increase the material processing costs, and consequently increase the cost of the final product. In this study, geopolymers were developed using red mud "in natura" (non‐processed slurry) and glass waste powder. Parameters including SiO2/Al2O3 ratio (4, 5, and 6), NaOH solution (6, 8, and 10 M) and curing duration (10, 28, and 56 days), were examined to understand the extent and degree of geopolymerization. Compressive strength tests were performed along with the analysis of their microstructural characteristics using quantitative x‐ray diffraction (QXRD) analysis based on Rietveld's refinement method, scanning electron microscopy (SEM), and thermal analysis (TG and DTA). As a result, higher SiO2/Al2O3 ratios and NaOH solution concentrations generally lead to greater compressive strength, which ranges from 9.7 to 43.1 MPa. Microstructural and compositional analyses demonstrated that the final products consist of an amorphous geopolymer binder, crystalline phases originating from raw RM and a neoformed phase, Garronite. This study showed that the RM without any processing step displays a high potential in the geopolymer production. [ABSTRACT FROM AUTHOR]

To tackle carbon emissions from cement production and address the decline in concrete's mechanical properties due to the substitution of cement with solid waste (glass powder) and natural mineral admixture (zeolite powder) materials, we employed glass powder and zeolite powder to create composite cementitious materials. These materials underwent alkali activation treatment with a 4% NaOH dosage, replacing 50% of cement to produce low-carbon concrete. Nanoindentation tests and mercury intrusion porosimetry (MIP) were employed to uncover the micro-mechanical properties and influencing mechanisms of alkali-activated low-carbon concrete. The results indicate a notable enhancement in the indentation modulus (19.9%) and hardness (25.9%) of alkali-activated low-carbon concrete compared to non-activated concrete. Simultaneously, the interfacial transition zone thickness decreased by 10 µm. The addition of NaOH led to a reduced volume fraction of pores (diameter >100 nm) and an increased fraction of pores (diameter < 100 nm), thereby reducing porosity by 2.6%, optimizing the pore structure of low-carbon concrete. The indentation modulus, hardness and volume fraction of the hydrated phase derived from Gaussian fitting analysis of the nanoindentation statistics showed that NaOH significantly improved the modulus and hardness of the hydration products of low-carbon concrete. This activation resulted in decreased LDC-S-H gel (low-density hydrated calcium silicate Ca5Si6O16(OH)·4H2O) and pore content, while the HD C-S-H gel (high-density hydrated calcium silicate Ca5Si6O16(OH)·4H2O) and CH (calcium hydroxide crystals Ca(OH)2) content increased by 13.91% and 23.46%, respectively. Consequently, NaOH influenced the micro-mechanical properties of low-carbon concrete by generating more high-density hydration products, reducing pore content, enhancing the pore indentation modulus and hardness, and shortening the interfacial transition zone. This study offers novel insights into reducing carbon emissions and promoting the use of solid waste (glass powder) and natural mineral admixture (zeolite powder) materials in concrete, contributing to the advancement of sustainable construction practices. [ABSTRACT FROM AUTHOR]

This paper investigates the effects of powder waste glass (PWG) at 10%, 15%, and 20 wt.% replacement of cement on the flow characteristic, setting time, compressive strength, water sorption, rate of the heat of hydration, cumulative heat of hydration; alkali-silica reaction (ASR), and microstructure characteristics of the resulting paste and mortar mixtures. A total of eight cementitious mixtures including two control mixtures have been investigated in this experimental program to evaluate the effect of PWG on the fresh and hardened state characteristics of paste and mortar mixtures. Test results show that the incorporation of PWG in the cementitious mixtures results in significant enhancement of their microstructure, increase in compressive strength, improvement in moisture barrier characteristics, and considerable reduction in the rate of the heat of hydration and cumulative heat of hydration. Up to 20 wt.% replacement of cement with fine PWG is seen to be innocuous from the standpoint of ASR. Furthermore, the use of PWG in paste results in delaying the initial and final setting times and increases the flow characteristic of the mortar mixture. [ABSTRACT FROM AUTHOR]

• Cooling on AZ31 alloy allows the deposition of HVOF HAp/S53P4 composite coatings. • Cracking and delamination occur during HVOF deposition if cooling is not controlled. • Hydrogen evolution on the AZ31 surface in SBF can be modulated depending on the HAp/S53P4 coating thickness. • Constituent phases on the coating do not have influence on hydrogen evolution behaviour. Bioactive thermal spray coatings produced via high-velocity oxygen fuel spray (HVOF) from hydroxyapatite (HAp) and bioactive glasses (BG) have the potential to be employed on temporary implants due to the ability of both HAp and BG to dissolve and promote osseointegration, considering that both phases have different reaction and dissolution rates under in-vitro conditions. In the present work, 75% wt. HAp - 25% wt. S53P4 bioactive glass powders were HVOF-sprayed to obtain HAp/S53P4 BG composite coatings on a bioresorbable AZ31 alloy. The study is focused on exploring the effect of the stand-off distance and fuel/oxygen ratio variation as HVOF parameters to obtain stable structural coatings and to establish their effect on the phases and microstructure produced in those coatings. Different characterization techniques, such as scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy, were employed to characterize relevant structural and microstructural properties of the composite coatings. The results showed that thermal gradients during coating deposition must be managed to avoid delamination due to the high temperature achieved (max 550 °C) and the differences in coefficients of thermal expansion. It was also found that both spraying distance and oxygen/fuel ratio allowed to keep the hydroxyapatite as the main phase in the coatings. In addition, in-vitro electrochemical studies were performed on the obtained HAp/S53P4 BG composite coatings and compared against the uncoated AZ31 alloy. The results showed a significant decrease in hydrogen evolution (at least 98%) when the bioactive coating was applied on the Mg alloy during evaluation in simulated body fluid (SBF). [ABSTRACT FROM AUTHOR]

The Al-7xxx series alloys exhibit exceptionally high strength, superior corrosion resistance, and excellent finishing characteristics. These qualities make them a common choice for manufacturing automotive and aerospace components. To further improve the mechanical and structural properties of these alloys, they are often reinforced with alloy powders. This study focuses on Alumix 431, an alloy of Al-7xxx series, combined with glass powder obtained from the grinding of waste glass. The primary aim of this research is to evaluate the use of glass powder as a reinforcement material in metallic alloys, such as aluminium alloys, with a particular emphasis on utilizing waste materials. The effect of glass powder on the surface and structural properties of Alumix 431 were investigated. A homogeneous mixture was obtained by blending the alloy with 15% (wt) glass powder. This mixture was then subjected to a shock pressure of 0.6 tons and underwent a heat-treatment process at 650 °C in a furnace for a 1 hour. The physical properties of the composite material-including hardness, density, surface topography, and microstructure-were characterized using optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction analysis. The addition of glass powder to the alloy led to enhanced hardness and density. The maximum hardness and bulk density values were achieved with the Alumix 431-15% GP alloy, measuring 41.846 N/mm² and 2.451 g/cm2, respectively. Conversely, the lowest values for apparent porosity and water absorption found to be 2.293% and 0.935%, respectively. Furthermore, the study identified the formation of various phases, such as Al2CuMg, diopside, cristobalite, between Alumix 431 and the glass powder. [ABSTRACT FROM AUTHOR]

By analyzing the interaction of different glass powders with Al powder and Zinc oxide, the effect of the wetting property of glass powders on the surface morphology of aluminum paste and the adhesion between aluminum paste and Zinc oxide substrate is discussed. The effect of wetting property for different glass powders on Al and Zinc oxide is analyzed by a high-temperature contact angle tester, and the contact angle-temperature and extension radius-temperature curves are determined during the wetting process of the glass powders. The microstructure of the cross-section of the glass powders and of the substrate, and the surface morphology of the aluminum pastes are analyzed by a scanning electron microscope. Adhesion between the aluminum paste and the Zinc oxide substrate is analyzed by a vertical tensile strength meter. The results show that the wetting property of glass powder is an important factor affecting the adhesion and surface morphology of the paste, and it plays a role in preventing excessive oxidation of aluminum paste during sintering at high temperatures. [ABSTRACT FROM AUTHOR]

Transparent oxyfluoride glass-ceramics (GCs) containing NaLuF 4 nanocrystals doped with Er3+ have been prepared by combination of glass melt-quenching and spark plasma sintering (SPS) of glass powders. The parameters, such as temperature, pressure, particle size and holding times were optimized to obtain the densification of the powdered samples together with the desired transparency. The major advantage of this technique is the shorter times (few minutes) compared with those used for the preparation of these GCs by conventional heat treatments (more than 10 h). SPS presents an important inconvenient, which is the carbon contamination coming from graphite punch, this has been improved using Pt foils. The structural study indicates the presence of nanocrystals corresponding to the crystalline phase α-NaLuF 4 , with a crystal size between 26 and 31 nm. The optical characterization, which includes near infrared emission and infrared-to-visible up-conversion, confirms the incorporation of Er3+ ions in the nanocrystals. The longer lifetimes of the 4I 11/2 and 4I 13/2 levels together with the enhancement of the upconverted green and red emissions (as well as the weak blue emission) in the SPS-GCs samples, if compared with the precursor glass, indicates the presence of Er3+ ions in a crystalline environment. Possible energy conversion mechanisms for the green and red emissions based on the temporal behavior of the upconverted luminescence are discussed. [ABSTRACT FROM AUTHOR]

New Hydroxyapatite-Bioactive Glass composites, xHA-(1-x)BG (x = 25, 50, and 75 wt %), are developed using HA and BGMS10 glass powders co-milled up to 2 h prior to Spark Plasma Sintering (SPS). Ball milling (BM) promoted the consolidation of HA-rich powders, whereas hindered the densification of 25HA-75BG samples. HA crystallite size is reduced from > 200 nm (unmilled) to 60 (x = 25 %) or 88 nm (x = 75 %) when using 2 h milled mixtures. Glass crystallization occurred in 75HA-25BG samples processed by SPS at 950 °C: a negligeable effect in the amount of the residual amorphous phase (12.3–13.3 wt %) is produced by BM, while changes are observed in the relative content of crystalline phases, with SiO 2 increases from 8.5 to 13.1 wt %, whereas α- and β-CaSiO 3 correspondingly decrease. Superior Young's modulus and Vickers hardness (130 GPa and 726, respectively) are obtained in HA rich products. Biological tests evidenced that the milling treatment does not determine negative consequences on cells viability. [ABSTRACT FROM AUTHOR]

CaO-Al 2 O 3 -B 2 O 3 (CAB) glass-ceramics with varying Al 2 O 3 content were fabricated using the melting method including melting and quenching of mixture of raw materials. The obtained glass powder was pressed into the desired shape and sintered for measurement. At 900 °C, the crystallinity initially increased and then decreased with increasing Al 2 O 3 content. The highest crystallinity of 62.29 % was obtained when the Al 2 O 3 content was 0.5 mol%, and exhibited excellent dielectric properties: ε r = 4.35, Q × f = 53,085 GHz, and τ f = –33.95 ppm/°C. The variation of dielectric properties with increasing Al 2 O 3 content is attributed to the crystallinity process. The crystallization process of CAB system was determined by crystallization activation energy, the lowest value of 302.085 kJ/mol corresponds to the highest crystallinity. The crystallization, dielectric properties and sintering behavior of CAB system indicate that CAB system prepared by melting method have promising prospect as new LTCC glass-ceramics. [ABSTRACT FROM AUTHOR]

Silica, a principal component of waste glass powder (GP) reacts with calcium hydroxide to form the hydration products, and the process is affected by the fineness of GP and the percentage of cement replaced. This study investigates the structural behavior of concrete incorporating GP in reinforced concrete members by 0%–25% (by weight) replacement of cement with GP along with 0%–0.45% addition of glass fibers (GFs). The compressive and tensile strengths, strength activity index (SAI), and failure mode of treated concrete mixtures have revealed the optimum values as 15% replacement of cement with GP with 0.3% of GF. In the second stage of experiment, reinforced concrete beams were cast at various percentages of GP and GF to investigate the load–deflection response. It was observed that the beam specimen treated with GP exhibited considerably less mid‐span deflection (14.8 mm) at failure as compared to the control beam (with no GP and GF) which failed at 29.4 mm. The beam specimen treated with GP only showed significant degradation in stiffness after the peak load due to the fact that a part of GP remains unreacted and acts as a filler. Moreover, the beam specimen cast at optimum percentages of GP (15%) and GF (0.3%) showed large mid‐span deflection and higher failure load as compared to the control beam. These results suggest that the partial replacement of cement with GP should be accompanied by the addition of fibers to avoid unwanted brittle responses of GP concrete, with the additional advantage of reducing the non‐biodegradable waste. [ABSTRACT FROM AUTHOR]

The stabilisation of expansive clay subgrades using recycled glass (RG) was proposed, as a sustainable ground improvement technique. Previous studies mainly focused on using RG powder with contents up to 10%, while the current study utilised sand-size particles and up to 40% RG content. Physical properties, compressibility, strength characteristics, and long-term climatic effects on the volumetric behaviour of stabilised clay were investigated. Volumetric responses of stabilised clay were analysed through a constitutive model developed for environmentally stabilised clay. The experimental results revealed that the plasticity of mixtures decreased by 30% as RG content increased to 40%. By using larger RG particles, the strength and bearing capacity increased by about 45% and 130% with the addition of 25% RG. However, adding about 6% of glass powder was sufficient to increase the strength and bearing capacity to about 100% and 200%, respectively. The swell-shrink results suggested that the maximum swelling was achieved in the second cycle in which the clay classification was converted from medium to high expansive clay. The experimental results were also compared and discussed with corresponding data collected from the literature. The outcomes of this study advance the prediction and understanding of the mechanical behaviour of RG-stabilised clay. [ABSTRACT FROM AUTHOR]

CaCl 2 can dissolve in the silicate glasses, and thus, using the CaCl 2 -bearing glass for the preparation of glass-ceramic could be a potential method for treating CaCl 2 -bearing wastes. In this work, two kinds of glass powders, CaO-MgO-Al 2 O 3 -SiO 2 and CaO-MgO-Al 2 O 3 -SiO 2 -CaCl 2 , were sintered at 825–850 ℃ to prepare the glass-ceramic. Besides, a low-pressure (19.1kPa) hot-pressing sintering technology was applied to reduce the porosity and pore size of the glass-ceramic. The addition of CaCl 2 (5 wt%) reduced the polymerization degree, glass transition temperature, crystallization peak temperature, and crystallization activation energy of the glass. Augite was the main crystalline phase of the glass-ceramic, and the addition of CaCl 2 promoted the precipitation of anorthite. The glass-ceramic prepared from the Cl-containing glass always exhibited a higher bending strength than that obtained from the Cl-free glass. When sintered at 825 ℃ for 8 h, the glass-ceramic showed the highest bending strength of 171 MPa. [ABSTRACT FROM AUTHOR]

The use of glass powder instead of cement as an auxiliary cementitious material can better alleviate environmental problems and energy problems. This experiment studies the influence of the fineness of glass powder and the substitution rate on the performance of mortar, to guide the actual project. The study found that with the increase of the substitution rate, the initial setting time becomes longer, the finer the fineness, the longer the initial setting time, but the difference between P-60 and P-90 decreases with the increase of the substitution rate. With the increase of substitution rate, the compressive strength of 7, 28 and 90 d increased first and then decreased. When the substitution rate was 5%, the compressive strength reached the maximum, but the 7 d compressive strength of P-30 with 5% substitution rate decreased slightly. With the increase of substitution rate, the cumulative hydration heat decreased gradually. The difference between P-60 and P-90 was not significant. Similar to the cumulative hydration heat, the hydration heat flow per gram of cement decreased gradually with the increase of substitution rate. It can be seen from nanoindentation that fineness and substitution rate have little effect on the properties of hydration products. With the increase of substitution rate, the total porosity decreases first and then increases. The porosity of glass powder mixed with P-30 is the largest, followed by P-60 and P-90, but the difference between the total porosity of P-60 and P-90 is not significant. In practical engineering, these two factors need to be considered in combination. [ABSTRACT FROM AUTHOR]