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Foam glass, an inorganic insulation material, is primarily manufactured from recycled glass or sand combined with a foaming agent. During fabrication, gas bubbles are generated in the softened glass, causing it to expand and form a cellular structure. Critical parameters such as cell size, type (closed or open cells), distribution, and uniformity significantly influence the physical and chemical properties of foam glass, ensuring sustained thermal efficiency. This research aims to produce foam glass exclusively from waste materials, thereby promoting the circular economy by utilizing container glass, cathode ray tube (CRT) glass, and aluminium dross. A comprehensive microstructural analysis, employing computer tomography and scanning electron microscopy, elucidated key properties including density, thermal conductivity, and water absorption. The manufactured foam glass exhibited lightweight characteristics, with a density ranging from 0.15 to 0.18 g/cm³. Additionally, the foam glass demonstrated low thermal conductivity (between 0.038 W/m·K and 0.05 W/m·K), which can be attributed to the heterogeneous distribution of cells that effectively reduce heat convection. This property makes foam glass an excellent thermal insulator. Furthermore, both high-absorption (open porosity) and low-absorption (closed porosity) foam glasses were successfully produced. [ABSTRACT FROM AUTHOR]

Discarded cathode-ray tube (CRT) glass is considered harmful waste because it contains poisonous lead. Hence, a study on the disposal of CRT glass and the potential risk of lead leaching is needed. This work performs the research on the panel-funnel glass separation method, an important step for CRT glass recycling. In the thermosol method, moderate temperatures of 565 ∼ 572 °C and 5 ∼ 7 min holding time are suitable for a complete panel-funnel glass separation. The acid etching method can achieve panel-funnel glass separation with low energy consumption by using a 10 wt% nitric acid solution as an agent. Panel-funnel glass can be quickly separated by a mechanical cutting method within four minutes and achieve a high glass recovery. A glass size of 2–10 mesh, a rotary shaking speed of 240 rpm, and a retention time of 120 h can accelerate the lead leaching of 133.34 mg/L from CRT glass in the leaching solution at pH 4.93. This work gives a systematic exploration into panel-funnel glass separation and lead leaching from CRT glass, which is potentially beneficial for CRT glass waste recycling, management, and disposal.

The construction industry is the major contributor of CO 2 emission around the globe. The rapid advances in the electronics industry have transformed the disposal of cathode ray tube glass waste (CRT-WG) into a prominent environmental concern. Recycling of CRT glasses as building materials can help in the production of sustainable construction. Numerous previous studies have documented that CRT-WG can be utilized either as a component of fine aggregate or binder material as it provides a cleaner solution and reduce carbon emission. Under this cleaner production and low CO 2 emission perspective, this paper provides a thorough review of the previous studies on the utilization of CRT glass as a partially and fully substitute of sand and cementitious material in mortar production and propose an application of CO 2 based circular economy model for reduce carbon emissions. This paper summarized the fresh, mechanical and durability properties of mortar incorporating treated and un-treated CRT-WG with different mineral additives and w/b ratios. Furthermore, this research explores the optimal proportions of CRT glass that can be use as replacements for sand and cement powder to make eco-friendly and sustainable low carbon mortar suitable for both structural and non-structural applications. More particularly, this review emphasizes the benefits, the need for additional research, and the drawbacks of CRT-WG use in construction building. Overall, this study proposes that incorporating CRT glass into building materials through a low CO 2 based circular economy offers significant potential advantages. This study will help in optimization of CRT glass in concrete mix design in combination with waste materials for sustainable construction. • Carbon neutrality concrete is the future of construction industry. • Optimum utilization of CRT glass in combination with waste materials can help in developing sustainable concrete. • CRT glass as building materials can helps in production of sustainable construction. • Proposed a CO 2 -based Circular Economy model for sustainable, low carbon concrete. [ABSTRACT FROM AUTHOR]

The center of attention of current research lies on utilizing E-waste cathode ray tube (CRT) glass as reinforcement to develop copper hybrid surface composites through friction stir processing route. Pure copper is taken as base material which is reinforced with different volume % of CRT glass (5, 10 & 15) and fixed amount (2%) of BN. The particle size of the reinforced CRT and BN particles are 30 µm and 10 µm respectively. The developed surface composite was characterized for microstructure through optical microscope and scanning electron microscope, density, micro hardness, tensile properties and wears behavior. The analysis confirms the presence of reinforcements in the matrix and also evidence for recrystallization. Density of the MMC is found decreasing while the hardness increases with addition of CRT & BN. The tensile and yield strength of unprocessed Cu is superior to that of MMC whereas it enhanced with raise in reinforcement content. Wear resistance of Cu depicts incremental trend with respect to reinforcement's addition. Scanning electron microscope was used to understand the worn out surface morphology and wear mechanism. Corrosion results depict that increase in CRT addition decrease the corrosion current density of surface composite. [ABSTRACT FROM AUTHOR]

The effect of the process atmosphere composition on the foam formation of cathode-ray tube (CRT) glass containing graphite and MnO 2 was studied using in situ environmental scanning electron microscopy at high temperature (HT-ESEM). When compared to He+4% H 2 , O 2 or air, water steam facilitates glass grain sintering. This is probably due to the formation of hydroxyl groups at the glass grain surface that locally decrease the glass viscosity. We have shown that increasing the steam pressure from 50 Pa to 750 Pa decreases both sintering and foaming onset temperatures by approximately 100 °C, favouring the formation of closed pores in viscous glass. At high temperature, the presence of water steam or oxygen promotes foam formation, while the presence of a reducing atmosphere (He+4%H 2) limits glass melt foaming. A synergetic effect of O 2 and H 2 O on the onset temperature of glass sintering and foam formation is evidenced. [ABSTRACT FROM AUTHOR]

Cathode ray tube (CRT) panel glass is processed into glass foams by using carbon and Mn 3 O 4 as foaming agents. We investigate the foaming ability and foaming mechanism of the mixture by varying the composition and the temperature. Carbon load of 5 wt% inhibits the sintering of the glass powder, while 2 wt% carbon promotes the coalescence of pores during foaming. Carbon load of ≤0.4 wt% is suitable for achieving low density foams (0.15–0.23 g cm-3) with closed pores (75–100%). Foaming is initiated by the reaction between carbon and Mn 3 O 4 and this is the main source of melt expansion. Reduction of cations in the glass melt, including Mn3+ dissolved from Mn 3 O 4 , makes an important contribution to the melt foaming at >800 °C. The main gaseous product is CO 2 (67–95 vol%). CO appears above 800 °C and the concentration increases with temperature. [ABSTRACT FROM AUTHOR]

The growing amount of waste materials and the shortage of landfill space highlights the urgency for alternative ways to recycle and reuse waste materials. Recycle and reuse waste materials would indirectly contribute to reducing the landfill space required for their disposal. This paper attempts to compare the physical and mechanical properties of byproduct material (steel slag) and waste material (Cathode Ray Tube (CRT) glass) that could potentially be used as substitutes for natural aggregates in the construction of road pavements. This paper discusses the feasibility of utilizing recycled steel slag and CRT glass which meet the test requirements for natural aggregates utilized for pavement construction. The study method for laboratory work was carried out following the American Society for Testing and Materials (ASTM) specifications. Physical and mechanical testing's, i.e. specific gravity, water absorption, soundness and Los Angeles abrasion tests, were carried out to determine the suitability of using steel slag and CRT glass in the construction of road pavements. Test results indicate that steel slag and CRT glass can be used as substitutes for natural aggregates due to their satisfactory physical and mechanical properties. It can be concluded that the use of steel slag and CRT glass as a replacement for natural aggregate resulted in the sustainable management of road base paving application. [ABSTRACT FROM AUTHOR]

The current work presents an experimental investigation and multi objective optimization of material and WEDM machining features for better surface finish (Ra) and material removal rate (MRR) for a newly made-up Mg/BN/CRT Hybrid MMC. Powder metallurgy route is followed for composite fabrication by reinforcing silica rich E-waste CRT panel glass powder of different particle sizes (10, 30 & 50 μm) at different weight percentages (5, 10 & 15%) and a fixed quantity of 2% Boron Nitride. Reinforcement weight percentage and size, pulse ON time, pulse OFF time and wire feed are considered as process parameters to design the WEDM experiments through Taguchi based orthogonal array technique. Based on the ANOVA results it is revealed that pulse ON time and reinforcement wt. % has higher influence over Ra and MRR when compared to any other parameters considered. The predicting ability of the developed mathematical models for MRR and Ra is found superior and it predicts similar values as that of experimental results. Multi objective optimization carried over through TOPSIS selects the optimal parameter for multi response and the TOPSIS recommended optimum parameter set delivers higher MRR (22.34 mm3/min) and reduced Ra (2.87 μm). [ABSTRACT FROM AUTHOR]

The performance of reinforced concrete beams in the presence of cathode-ray tube (CRT) glass waste is examined. Four concrete mixes containing 0%, 10%, 20%, and 30% CRT glass waste as partial replacement of sand were prepared. The compressive and flexural strength as well as the modulus of elasticity of concrete were determined. Reinforced concrete beams with varying amounts of CRT glass were prepared and the three-point bending test was conducted. The load-deflection curve as well as the strain distribution along the depth of the beams were determined. Concrete containing CRT glass showed an increase in compressive strength, flexural strength, and modulus of elasticity especially at 10% replacement level. The load carrying capacity of reinforced concrete beam is higher when 10% of sand is replaced with CRT glass compared to the control beam and the beams with 20% and 30% CRT glass substitution. The failure mode of the reinforced concrete beams is flexural failure, and the failure pattern is similar for all beams. Strain distribution showed a better ductility at control beam where the deflection was higher than the other beams at the same load. Numerical analysis was conducted, and comparison was made with the experimental results. The comparison showed the accuracy of the software used, where the results of maximum load capacity and maximum deflection were very similar, and the difference did not exceed 5%. In addition, the tensile damage generated by the numerical analysis was very similar to that obtained by the experimental study.

• Research of micro TiO 2 and CRT glass application in pervious concrete paving flags. • Testing of surface, mechanical and durability properties and the infiltration rate. • Testing of flag's ability to reduce the transport of pollution driven by rainwater. • CRT glass reduced wear resistance while TiO 2 reduced the USRV value of flags. • CRT glass can be used in pavement structure and micro TiO 2 is photocatalytic active. In the subject of pavement engineering, real-life conditions must be recreated using carefully selected materials and techniques. This is especially true for the evaluation of non-standard, waste materials prior to their usage in pavement structure. The objective of this study is to ascertain the effects of partial cement replacement with cost-effective micro TiO 2 and full fine aggregate replacement with CRT (cathode ray tube) glass on the characteristics of pervious concrete paving flags and their capacity to reduce pollutants carried by rainwater. Within the research, standard test methods for paving flags characterisation are used (EN 1339) along with some new and innovative research approaches to environmental impact assessment simulating real-life conditions. Results indicate a high influence of used materials on pervious concrete properties, both separately and combined. When applied separately, CRT glass and TiO 2 exhibited reduced bending strength; however, when put together, bending strength improved. TiO 2 decreased the unpolished slip resistance value (USRV) of flags while CRT glass reduced wear resistance. Although the infiltration rate was greatly improved, neither component had a substantial impact on water absorption. Environmental impact assessment results support the safety of use of both materials in paving flags. Finally, by using CRT glass and micro TiO 2 , innovative, environmentally friendly, and cost-effective paving product can be produced for sustainable development improvement within pavement engineering. [ABSTRACT FROM AUTHOR]

Disposal of waste CRT glass is now an urgent environmental protection issue. We collected waste CRT glass from monochrome and color television sets, analyzed their chemical compositions using X-ray fluorescence, and studied the leaching characteristics of Pb in the glass using sulfuric and nitric acids and acetic acid buffer leaching toxicity tests. The results showed that the order of the Pb leaching levels was color panel glass < monochrome glass < color funnel glass. The average Pb concentrations leached in sulfuric and nitric acids from color funnel and panel glasses and from monochrome funnel and panel glasses did not exceed the regulatory limits for Pb according to the China Identification Standards for Hazardous Waste-Identification for Extraction Toxicity. Only the average concentration of Pb leached in acetic acid buffer from color funnel glass exceeded the regulatory levels for Pb while those from other glasses were lower than 1 mg/L. Monochrome panel and funnel glasses and color panel glass can be disposed off as common industrial solid waste or co-disposed off with municipal solid waste. Color funnel glass, however, should be managed and disposed off in strict conformity with the requirements for hazardous waste disposal. [ABSTRACT FROM AUTHOR]

The influence of alumina oxide on the crystallization of silica-strontium-barium glass from cathode ray tube (CRT) was studied by means of thermal analysis. Thermal characteristics of glasses such as the transition temperature T , the crystallization temperature T and thermal stability parameter were determined by DTA/DSC method. The crystallization ability of the obtained glasses was also determined independently by the gradient furnace technique. The crystalline phase was determined by the X-ray diffractometry. The microstructure of the samples was studied by SEM technique. The linear expansion coefficients of glasses as a function of temperature were measured. Analysis of the local atomic interactions in the structure of glasses was used to explain the course of the crystallization. The effect of AlO content on the CRT glass composition was studied by FTIR and solid-state F MAS-NMR spectroscopy. [ABSTRACT FROM AUTHOR]

The amount of electronic waste (e-waste) is rapidly increasing due to economic growth and the advancement of information technology. End-of-life (EOL) cathode ray tube (CRT) TVs and computer monitors make up the greatest proportion of the total mass of e-waste. Because of international trade in secondhand CRT TVs and monitors and the toxic substances contained in them, the EOL fate of CRTs is an emerging concern in developing countries. In this study, the recycling and treatment techniques of EOL CRT TVs/monitors were investigated in three Southeast Asian countries (Indonesia, the Philippines, and Vietnam). The current recycling methods of CRT TVs/monitors in Japan and China were also reviewed for comparison. The process flows and destinations of materials or parts at both formal and informal recycling sites were compared. Among the three countries, only one formal facility in the Philippines has automated processing equipment for CRTs. CRT glass handled by informal sectors was illegally dumped or disposed of with regular municipal solid waste. Some waste CRT glass was also informally recycled as glass materials or exported to China. A number of recommendations are made to improve recycling conditions at both formal and informal recycling sites. [ABSTRACT FROM AUTHOR]

With more and more cathode ray tube (CRT)-based sets reaching their end-of-life or being replaced, how to deal with the CRT glass has become a global concern due to its high lead level. There is a pressing and ongoing need to develop new recycling methods for CRT glass. In this work, the alkaline leaching of CRT funnel glass in the sulfur-containing medium (S and NaS) was probed. The effects of alkaline concentration, S/Pb molar ratio, temperature and leaching time were investigated. The results showed that the recovery rate of both Si and Pb increased with increasing alkaline concentration; however, it decreased again when the concentration was higher than the critical value 6 M. The recovery rate of Pb in both media decreased with increasing S/Pb molar ratio. As a comparsion, the recovery rate of Si did not change significantly. The extraction of Si and Pb, especially Si, tightly depended on the temperature. They also increased with extending of time, however, they tended to decrease when the reaction time exceeded 8 h. The optimal condition was determined as: alkaline concentration 6 M, S/Pb molar ratio 1.0:1, temperature 180 °C and leaching time 8 h. [ABSTRACT FROM AUTHOR]

Discarded cathode-ray tube (CRT) glass is considered harmful waste because it contains poisonous lead. Hence, a study on the disposal of CRT glass and the potential risk of lead leaching is needed. This work performs the research on the panel-funnel glass separation method, an important step for CRT glass recycling. In the thermosol method, moderate temperatures of 565 ∼ 572 °C and 5 ∼ 7 min holding time are suitable for a complete panel-funnel glass separation. The acid etching method can achieve panel-funnel glass separation with low energy consumption by using a 10 wt% nitric acid solution as an agent. Panel-funnel glass can be quickly separated by a mechanical cutting method within four minutes and achieve a high glass recovery. A glass size of 2–10 mesh, a rotary shaking speed of 240 rpm, and a retention time of 120 h can accelerate the lead leaching of 133.34 mg/L from CRT glass in the leaching solution at pH 4.93. This work gives a systematic exploration into panel-funnel glass separation and lead leaching from CRT glass, which is potentially beneficial for CRT glass waste recycling, management, and disposal. [ABSTRACT FROM AUTHOR]

In the last decades, electronic goods have become a part of our life, as a technical support for different fields, either social, comunication, travel, transportation. The end-of-life electronics are also, a part of our social resposibilities and this matter has to be managed in an ecological manner and taking into account the economical implications. Annually, the amount of WEEE collected in EU increases, as a response of the joined efforts of all the factors involved: producers, collectors, local authorities, electronic waste recyclers. A sustainable management of waste electronics, with focus on CRT wastes, has become a real challenge for the recyclers, due to the hazardous components included -- different types of activated glass with lead content. The aim of this study is to reveal some economic and ecological figures involved in the WEEE management in EU. Content of this study can be used by the recyclers and producers, in order to find the proper way to approach the CRT waste management, to obtain the best results of recycling. [ABSTRACT FROM AUTHOR]

Panel (P) and funnel (F) glasses from Cathode Ray Tube (CRT) have been used to obtain glass foams by a simple and economic processing route, consisting of direct heating the glass powders at relatively low temperatures (650-750 °C) using different foaming agents (FA) such as egg shells, calcite, dolomite. Mixtures in different proportions of P and F glass powders were tested and the effects of composition and heat treatment temperature on the foaming behaviour were evaluated. Glass foams featuring apparent density and compressive strength values of 0.29 g/cm³ and 2.34 MPa, respectively, could be produced from a P/F ratio=1 with added 3 wt% of egg shells upon heat treating at 700 °C for 15 min. The P/F ratio was found to strongly influence the foaming behaviour and, consequently, the physical properties of the final foam glass. The relative performance of other foaming agents under a given set of experimental conditions revealed to be dependent on the type of glass (composition and thermal properties). [ABSTRACT FROM AUTHOR]

• The reduction of lead leachate of alkali-activated materials is studied. • High particle size of CRT glass reduces leachate of alkali-activated materials. • Funnel CRT glass has less applications at this moment and it is landfilled. Alkaline activation is an interesting manufacturing process from an environmental point of view as it allows the use of waste containing amorphous SiO 2 and Al 2 O 3 as starting material, such as glass, bottom and fly ashes. However, the presence of heavy elements in these waste materials can limit their use since they are released during the dissolution stage and not always enter totally in the new structure formed. In this work, the feasibility of using glass from Cathode Ray Tubes (CRT) with a high particle size to reduce lead leaching has been studied. [ABSTRACT FROM AUTHOR]

Abstract: The cathode ray tubes (CRTs) glass of discarded computer monitors and television sets are identified as hazardous materials due to its high content of lead, however, nowadays appropriate CRT glass remediation technologies are insufficient. This research work studies the feasibility of CRT glass (MG, G) use in the mortar as natural river sand fine aggregate replacement. Fly ash (F) and ground granulated blast-furnace slag (GGBFS) as mineral admixture were used to replace 25% Portland cement. The effect of MG, G on the fresh mortar behavior and properties of mortar containing different mineral admixtures were investigated, the results showed higher initial slump flow diameter values and better slump flow preservation. Higher mechanical properties of mortar were observed when natural river sand (R) was replaced by MG, G, while the presence of the MG, G in mortar enhanced drying shrinkage and alkali-silica reaction (ASR) expansion values. [Copyright &y& Elsevier]

Abstract: The leaching behavior of cathode ray tube (CRT) funnel glass containing 23 mass percent of Pb in 0.001N HCl, distilled water, and 0.001N NaOH at 90°C was investigated using a static method. The weight loss and leached amount of each component was measured and surface changes observed by SEM. The leaching mechanism is discussed. In acid solution, the leached amount of Pb showed t 1/2 dependence, that is, diffusion-controlled dependence, which is common in lead silicate glasses. In water and basic solutions, the leached amount showed saturation after higher initial dissolution than in acid and the deposition of many particles on the surface was observed. The amount leached was less for Pb than other components. The deposited particles formed a protective layer, which suppressed the dissolution of the glass. This dense layer must be formed as a result of a high initial dissolution rate. [ABSTRACT FROM AUTHOR]

Abstract: In the present work, the feasibility to substitute feldspar raw material in a porcelain stoneware body with Panel Cathode Ray Tube (CRT) glass was investigated. A standard batch and a composition, where 35wt.% Na-feldspar was substituted by CRT glass, were sintered at different temperatures in the range of 1000–1250°C. The degree of the densification was studied by evaluation of the closed and total porosity, while the sintering rate was estimated by non-isothermal dilatometric measures. The variation of the crystalline phase composition was evaluated by XRD analysis. From the preliminary study other ceramic samples with different percentages of CRT glass (i.e. 2.5, 5 and 10wt.%) were prepared and fired in industrial kiln. The sintering parameters, the microstructure and the mechanical properties were measured and compared with the standard composition. [Copyright &y& Elsevier]

Abstract: The feasibility to prepare foamed glass specimens by using waste TV monitor (panel) glass as starting material under hydrothermal hot-pressing (HHP) conditions, followed by a conventional heating of the compact, was investigated. Hydrothermally hot pressed glass compacts were preliminarily prepared at a constant temperature of 200°C, with a loading pressure of 20MPa and two different water contents (5 and 10wt%), for reaction intervals between 0.5 and 2h, employing a glass particle size <38μm. After the powder densification stage, firing of the compacted disk glass was conducted over a temperature range of 650–850°C for 1h. Microstructural observations conducted by SEM showed the formation of a new glass phase which incorporates water, this phase was formed during the glass densification stage at 200°C for 2h, with a water content of 10wt%. The lowest apparent density achieved on these glass compacts heated at 700°C for 1h was 0.36g/cm3. This value is similar to that of other foamed glasses that have close cell network and low thermal conductivity (0.0021W/cm/°C). [Copyright &y& Elsevier]

• An effective utilization of e-waste plastics and glasses in construction products is reviewed. • Potential use of e-plastic in cement and concrete composites are discussed. • Performance of cementitious composites with e-glass and e-fibre are reported. • The e-waste has great potential to use as construction material. The exponential development of the electronic industry and changes in people's lifestyle have increased the discarding rate of waste electronic appliances and electrical equipments rapidly. The disposal of electronic waste (e-waste) has become a serious challenge to developing and developed countries as toxic substances and heavy metals present in e-waste could harm human health and the atmosphere. From the perspective of environmental concerns, it is necessary to properly dispose or reuse e-waste in any forms to prevent pollution. In recent years, a growing number of studies are primarily associated with utilization of e-waste as construction materials. This paper provides a critical and comprehensive review of different types of e-waste which can be utilized as source material in the form of binder, fine/coarse aggregate, and fibre in the mortar, concrete, and precast products. More specifically, this review highlights the positive aspects, future research needs, and limitations of using e-waste in construction. Overall, it is suggested that e-waste offers huge potential benefits when it is utilized in construction products, thereby reduces e-waste management problems and saves the earth from environmental pollution. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper presents novel research on a fluidized bed combustion (FBC) fly ash-based geopolymer as a contribution to the problem of FBC fly ash disposal, and a proposal for a new geopolymer composition—an environmentally friendly material that is possible to use in construction. Geopolymer samples of various composition (containing FBC fly ash as the main raw material, metakaolin and CRT glass as additional components, and sodium silicate and sodium hydroxide as activators) were subjected to flexural and compressive strength tests. An investigation on the effect of the demolding time was carried out on one selected mixture. The test showed that both the composition and the demolding time have a decisive influence on the basic mechanical properties. A mixture containing FBC fly ash to metakaolin in a mass ratio of 3:1, removed from the mold after 14 days, was found to be the best in terms of the mechanical parameters expected from a material that could be used in construction, e.g., for the production of precast elements. According to the results obtained, FBC fly ash is a promising and environmentally friendly raw material for the production of geopolymer, with good mechanical properties and low density. Moreover, a high compressive strength can be obtained by curing the geopolymer at ambient temperature. [ABSTRACT FROM AUTHOR]

Geopolymers can be treated as an environmentally friendly alternative for concrete and enables utilization of various wastes. This paper focuses on the possibility of application of discarded cathode ray tube (CRT) glass inside a metakaolin-based geopolymer in the form of an aggregate, providing an ecological method of recycling of this hazardous material. The main goal of this paper was to develop an optimal composition of a new geopolymer and to describe its behavior under varying curing conditions. A geopolymer made of different mixtures was subjected to flexural and compressive strength tests. The density, mass loss, temperature changes, and metals leaching were determined as well. The results demonstrated that neither the content of CRT glass nor the curing regime has a significant influence on the mechanical behavior. However, the strength of the geopolymer containing 50% CRT glass by mass increased with time in contrast to a geopolymer with a higher CRT glass content. The development of temperature inside the mixture was dependent on the amount of metakaolin. The concentration of toxic metals in an aqueous extract decreased considerably after the encapsulation of CRT glass inside the geopolymer. The presented results indicate that discarded CRT glass can be considered an aggregate for a metakaolin-based geopolymer. The new material shows high strength and makes the CRT glass safe for the environment. [ABSTRACT FROM AUTHOR]

The performance of reinforced concrete beams in the presence of cathode-ray tube (CRT) glass waste is examined. Four concrete mixes containing 0%, 10%, 20%, and 30% CRT glass waste as partial replacement of sand were prepared. The compressive and flexural strength as well as the modulus of elasticity of concrete were determined. Reinforced concrete beams with varying amounts of CRT glass were prepared and the three-point bending test was conducted. The load-deflection curve as well as the strain distribution along the depth of the beams were determined. Concrete containing CRT glass showed an increase in compressive strength, flexural strength, and modulus of elasticity especially at 10% replacement level. The load carrying capacity of reinforced concrete beam is higher when 10% of sand is replaced with CRT glass compared to the control beam and the beams with 20% and 30% CRT glass substitution. The failure mode of the reinforced concrete beams is flexural failure, and the failure pattern is similar for all beams. Strain distribution showed a better ductility at control beam where the deflection was higher than the other beams at the same load. Numerical analysis was conducted, and comparison was made with the experimental results. The comparison showed the accuracy of the software used, where the results of maximum load capacity and maximum deflection were very similar, and the difference did not exceed 5%. In addition, the tensile damage generated by the numerical analysis was very similar to that obtained by the experimental study. [ABSTRACT FROM AUTHOR]

Cathode Ray Tube (CRT) glass belongs to the group of wastes which are hard to be recycled due to their toxic metals content. Geopolymers are relatively new environmentally friendly materials which allow for the use of different types of wastes within their matrix. The following paper combines both issues and presents a new geopolymer mixture containing discarded CRT glass as a replacement for an aggregate. The main goal of the paper is to describe the basic mechanical behavior of the new type of metakaolin-based geopolymer and to discuss different factors influencing it. After the preliminary research, the mixture containing 50% of CRT glass was chosen for further tests. However, according to results, CRT glass content has no evident influence on flexural or compressive strength. Summarizing the second part of the research, it was decided that the following parameters are optimal from the mechanical, economic and environmental points of view: metakaolin to CRT glass ratio 1:1 (by mass), CRT glass of size up to 4 mm, curing at the room temperature, sodium hydroxide concentration 10 mol/L. According to the authors, the presented geopolymer is a promising building material. Further tests shall be done to describe new material more precisely. [ABSTRACT FROM AUTHOR]