Types Of Powders Research Articles

Effect of Moisture Content Difference on the Analysis of Quality Attributes of Red Pepper (Capsicum annuum L.) Powder Using a Hyperspectral System.

The variety of characteristics of red pepper makes it difficult to analyze at the production field through hyperspectral imaging. The importance of pretreatment to adjust the moisture content (MC) in the process of predicting the quality attributes of red pepper powder through hyperspectral imaging was investigated. Hyperspectral images of four types of red pepper powder with different pungency levels and MC were acquired in the visible near-infrared (VIS-NIR) and short-wave infrared (SWIR) regions. Principal component analysis revealed that the powders were grouped according to their pungency level, color value, and MC (VIS-NIR, Principal Component 1 = 95%; SWIR, Principal Component 1 = 91%). The loading plot indicated that 580-610, 675-760, 870-975, 1020-1130, and 1430-1520 nm are the key wavelengths affected by the presence of O-H and C-H bonds present in red pigments, capsaicinoids, and water molecules. The R2 of the partial least squares model for predicting capsaicinoid and free sugar in samples with a data MC difference of 0-2% was 0.9 or higher, and a difference of more than 2% in MC had a negative effect on prediction accuracy. The color value prediction accuracy was barely affected by the difference in MC. It was demonstrated that adjusting the MC is essential for capsaicinoid and free sugar analysis of red pepper.

Electrode experimental study of optimal tourmaline powders for filtration enhancement

AbstractTourmaline (TM) has received extensive interest in the purification field due to its unique spontaneous polarization. In this paper, the effects of three sizes of purified TM samples on the air filters were studied. The electrode performance of TM samples was investigated using piezoelectric and pyro‐electric experiments. The results show an electrode from the 0.074 mm separated TM had the superior property. Three types of TM powders with the highest B2O3% content were adhered to the filter to evaluate the filtration performance. Elbaite 0.074 mm with 9.34 B2O3% content had the optimal filtration efficiency when the pressure drop increased slightly. The Rietveld method was used to refine the samples X‐Ray diffraction patterns to obtain the crystal structure. The electrostatic adsorption caused by the TM spontaneous polarization contributes to improving the filtration property of the filter materials.

Characterization of Virgin, Re-used, and Oxygen-reduced Copper Powders processed by the Plasma Spheroidization Process

Fabrication of parts with high mechanical properties heavily depend on the quality of powder deployed in the fabrication process. Copper powder in three different powder types were spheroidized using radio-frequency inductively coupled plasma (ICP) spheroidization process (TekSphero-15 system). The characterized powders include virgin powder as purchased from the powder manufacturer, powder used in electron beam powder bed fusion (EB-PBF) process, and reconditioned powder, which was used powder that underwent an oxygen-reduction treatment. The goal of spheroidizing these powder types was to evaluate the change in powder morphology, the possibility of enhancing the powder properties back to their as-received conditions, and assess oxygen reduction of the powder lots given their initial oxygen contents. Also, to investigate the impact of re-spheroidization on powder properties, the second round of spheroidization was performed on the already used-spheroidized powder. The impact of powder type on powder sphericity and particle size distribution was evaluated using the image analysis of scanning electron microscope (SEM) micrographs and laser diffraction, respectively. The spheroidized powder showed higher sphericity and more uniform particle size distribution overall. Depending on the powder collection bin, second round of spheroidization affected the powder sphericity differently. The possibility of deploying the plasma spheroidization process as an alternative oxygen-reduction technique was also investigated through tracking the powders’ oxygen content using inert gas fusion method before and after the spheroidization. The plasma spheroidized powder showed less oxygen content than the hydrogen-treated powder. The second round of spheroidization caused no change in oxygen content. The correlation between oxygen-reduction and created cracks was discussed and compared between plasma spheroidization and hydrogen-treatment. The plasma spheroidization process created a powder with higher sphericity, uniform particle size, and less oxygen content.

Electrostatic powder spreading for metal powder bed fusion applications

Typical powder bed fusion processes spread each layer of powder by pushing it across the build area with a spreader bar or roller. While simple, these methods require good flowing powder and do not have the ability to place more than one powder type per layer. This naturally limits the ability to incorporate more than one material onto each powder layer in powder bed additive manufacturing processes. Here we demonstrate electrostatic powder spreading, a method to deposit a powder layer without mechanical contact with the previous layers. Electrostatic powder spreading (ESPS) uses an electric field formed between a powder container and a counter electrode to move powder particles from the container to the powder bed. We show that the rate at which powder is deposited can be controlled by adjusting the strength of the electric field. Correspondingly, the deposited layer thickness is controlled by the strength of the electric field and the recoating speed. To demonstrate the feasibility of ESPS for laser powder bed fusion powder spreading, nearly fully dense (> 99.8%) coupons were built in a commercial L-PBF machine using the ESPS setup. Finally, we achieve 2D patterning of a single layer by using an array of electrodes and switching the applied electric field on and off. ESPS represents a method to produce an arbitrary patterned multi-material powder bed without complicated powder removal steps and easy implementation into existing L-PBF machines. Furthermore, ESPS presents an opportunity to build parts with 3D gradients in material properties.

Viscosity transition from dilute to concentrated cementitious suspensions: the effect of colloidal interactions and flocs percolation

The current paper deals with the effect of powder type and chemical admixtures on the rheological properties of mineral suspensions. The plastic viscosity of calcite, cement, and fly ash suspensions with or without superplasticizers (SP) and hydration retarders was characterized in a wide range of solid volume fractions. The results show that the plastic viscosity of suspensions increases with the decrease in particle size, and strongly decreases with the presence of superplasticizers. Besides, for reactive suspensions, hydration retarders decrease the plastic viscosity of the suspension, while competitive adsorption occurs when adding retarders to suspensions containing SP, leading to an increase in the plastic viscosity. Based on the experimental results, a relative plastic viscosity, i.e., the ratio between the total plastic viscosity and the theoretical viscosity contributed by the hard-sphere, is proposed to assess the effect of the contribution of colloidal forces. Moreover, the solid volume fraction of flocs in colloidal suspensions before percolation is identified by comparing the measured plastic viscosity with the Krieger-Dougherty model. Finally, a theoretical approach to determine the percolation packing fraction of minerals powders is further proposed.

Low-cost VIS/NIR range hand-held and portable photospectrometer and evaluation of machine learning algorithms for classification performance

In this study, the electronic design of a low-cost and portable spectrophotometer device capable of analyzing in the visible-near infrared region was established. The design of C#.NET-based user-friendly device control software and the development of machine learning algorithms for data classification as well as the comparison of the results were presented. When the spectrophotometer design and implementation studies are reviewed in the literature, two groups of subjects become prominent: (i) a new device fabrication, (ii) solution approaches to current problems by combining commercial portable spectrometer systems and devices with artificial intelligence applications. This work encompasses both groups, and a supportive approach has been followed on how to transform the theoretical knowledge into practice in device development and supportive software with the help of machine learning approaches from design to production. Three commercial spectral sensors, each with six photodiode arrays, were adopted in the spectrophotometer. Thus, 18 features belonging to each sample were acquired in the optical spectral region in the 410 nm to 940 nm band range. The spectral analyses were conducted with 9 different food types of powder or flake structures. A Support Vector Machines (SVM) and Convolutional Neural Network (CNN) approaches were employed for data classification. As a result, SVM and CNN achieved 97% and 95% accuracies, respectively. Moreover, we provided the spectral measurement data, the electronic circuit designs, the API files containing the artificial intelligence algorithms and the graphical user interface (GUI).

Performance of Ordinary and Self-Compacting Concrete with Limestone after Freeze–Thaw Cycles

Freeze–thaw resistance is a significant issue in the durability of concrete; however, it is not widely discussed in the context of limestone addition to concrete. The present study aims to compare the effect of the addition of different types of limestone powder on the frost resistance of ordinary and self-compacting concrete. Three types of limestone powder were added to concrete in an amount of 15% and 30% cement weight. Compositions with and without the air-entraining admixture were prepared in each instance. Research included tests of consistency, air content, air void distribution, compressive strength and freeze–thaw resistance after 100 and 200 freeze–thaw cycles. The obtained results indicate that in the case of both aerated and non-aerated concrete mixtures, weight loss and the decrease in strength after 100 freeze–thaw cycles did not exceed the allowable range. Concretes with limestone powder did not significantly differ in frost resistance from reference concretes. The type of limestone had an effect on the effectiveness of admixtures, as well as the compressive strength and freeze–thaw resistance of concretes without an air-entraining admixture.

Biological Effects and Toxicity of Compounds Based on Cured Epoxy Resins.

The aim of this work was to investigate selected biological and toxicity properties of cured epoxy resin-based compounds based on a bisphenol A epoxy resin, cold-cured by a polyamide and containing two types of metal powders (aluminum and copper). This study involved cytotoxicity analysis, pH measurements, absorbance measurements and sterilization. The cytotoxicity analysis was conducted to determine the harmful degree of the cured epoxy resin. Aimed at identifying toxic agents in cured compounds, the cytotoxicity analysis involved absorbance measurements in an entire wavelength range. Cytotoxicity and absorbance results demonstrated that the extracts of all the tested resin samples had no cytotoxic effects on the cells of living organisms. The absorbance values obtained over the entire wavelength range did not point to the formation of aggregations, which proved that no toxic agents harmful to living organisms were extracted from the resin samples. Based on the results obtained, it can be concluded that all tested compounds, based on epoxy resins, which are also used as adhesives in various applications, are essentially safe materials when using such formulations in a cured state.

Fire Extinguishing Performance of Chemically Bonded Struvite Ceramic Powder with High Heat-Absorbing and Flame Retardant Properties.

Struvite is a chemically bonded ceramic product in the pipeline of a sewage treatment plant. In order to explore the fire extinguishing potential of struvite, a new type of struvite ultrafine dry powder with excellent performance was prepared by a simple process, and its fire extinguishing performance and mechanism were analyzed in depth. Under the same process conditions, the refinement degree (D50 = 5.132 μm) and the specific surface area (BET = 25.72 m2/g) of ultrafine struvite were larger than those of NH4H2PO4 (D50 = 8.961 μm, BET = 13.64 m2/g), making struvite more suitable for fire extinguishing. Besides, the pyrolysis process of struvite was relatively concentrated and absorbed more heat in a short time. Its heat absorption (458.4 J/mg) was higher than that of NH4H2PO4 (156.4 J/mg). Water, ammonia, and PO· were released during the pyrolysis of struvite, which effectively reduced fire temperature, diluted oxygen concentrations and captured free radicals. At the same time, the final products were magnesium orthophosphate and magnesium pyrophosphate, which formed a dense flame-retardant ceramic layer with good thermal insulation and environmental protection functions. In these cases, the fire extinguishing mechanism of struvite was determined to have three stages: the cooling effect, the asphyxiation effect, and the chemical effect. Correspondingly, the fire extinguishing time of struvite was three seconds faster than that of ammonium phosphate under 0.2 MPa based on the local oil basin test.

Lithium doped biphasic calcium phosphate: Structural analysis and osteo/odontogenic potential in vitro.

Biphasic calcium phosphate (BCP) is generally considered a good synthetic bone graft material with osteoinductive potential. Lithium ions are trace elements that play a role in the bone-remodeling process. This study aimed to investigate the effects of lithium ions on the phase, crystal structure, and biological responses of lithium doped BCPs and to identify improvements in their osteogenic properties. Lithium-doped BCP powders with different doping levels (0, 5, 10, and 20 at%) were synthesized via the co-precipitation method. We found that the four types of lithium-doped BCP powders showed different phase compositions of hydroxyapatite and β-tricalcium phosphate. In addition, lithium ions favored entering the β-tricalcium phosphate structure at the Ca (4) sites and calcium vacancy sites [VCa(4)] up to 10 at%. This substitution improves the crystal stabilization by filling the vacancies with Ca2+ and Li+ in all Ca sites. However, when the concentration of Li ions was higher than 10 at%, lithium-induced crystal instability resulted in the burst release of lithium ions, and the osteogenic behavior of human dental pulp stem cells did not improve further. Although lithium ions regulate osteogenic properties, it is important to determine the optimal amount of lithium in BCPs. In this study, the most effective lithium doping level in BCP was approximately 10 at% to improve its biological properties and facilitate medical applications.

In-situ monitoring of powder bed fusion of polymers using laser profilometry

Process monitoring allows for unique opportunities to capture information at intermediate layers during fabrication for part qualification, but also to improve process robustness by identifying issues before yield or quality is reduced. An industrial-grade laser profilometer has been integrated for the first time in a commercial polymer laser sintering machine and used to monitor powder bed quality and potentially qualify parts during production. Powder layer quality was measured in different conditions and changed drastically as a function of recoating speed, preheating temperature but also particle shape. The effective layer thickness was obtained for the first time in PBF of polymers, and gradually increased with the layer count until reaching a plateau at the nominal layer thickness. Powder layer density could be calculated as well and lies between 34 and 65 %, depending on the powder type and layer count. Finally, curling increased with decreasing preheating temperature, ranging from 70 µm to 350 µm i.e. until collision with the recoater. Based on the measured degree of curling, mitigation strategies could be integrated using a closed-loop feedback control. Effective process monitoring such as the one provided with laser profilometry may enable the development of new materials featuring more complex processing conditions, but also larger machines where thermal uniformity might be an issue.

Simultaneous modeling prediction of three key quality attributes of tablets by powder physical properties

Tensile strength (TS), solid fraction (SF), and tablet weight variability (TWV) are all key quality factors to be considered during the tablet manufacturing process. For predicting them, a novel powder texture measurement methodology was proposed to study the texture attributes of 32 types of powders, and 10 types of unknown powders were used to validate the model. Principal component analysis (PCA) was used to classify the powders. Standard least-squares models were constructed to predict the TS and SF of tablets using texture properties as independent variables, with model R2 values of 0.9188 and 0.8672, respectively. Moreover, due to the advantages of decision trees in classification performance and computation time, multi-node decision trees were constructed, and the approximate range of the TS and SF can be quickly predicted by using only 2-4 key texture attributes. Partial least squares-discriminant method (PLS-DA) algorithm was used to determine whether TWV was qualified by using texture and other physical attributes of powders. In conclusion, the constructed models predicted TS, SF, and TWV well and provide an effective reference for facilitating the development of tablet formulation for direct compression (DC).

Mechanism of Different Mechanically Activated Procedures on the Pozzolanic Reactivity of Binary Supplementary Cementitious Materials

In this study, a type of fly ash and iron tailing powder were used as a binary supplementary cementitious material (SCM) and two different mechanically activated procedures, named coalescent activation and separated activation, were carried out to improve the pozzolanic reactivity. Then, three binary supplementary cementitious materials were used to replace 30 wt% of ordinary Portland cement to develop cemented mortars, and the compressive strength, hydration products, and micro-structure were studied. The experimental results indicated that the activated supplementary cementitious materials increased the compressive strengths of the mortars by 5.4% and 13.2%, negligibly changed the hydration product types, and impacted the quantity only. The application of SCMs also prolonged the setting time and decreased the hydration rate, profiting the application. Simultaneously, the micro-pore structure was ameliorated, and the porosity decreased. Therefore, comprehensively considering the improved mechanical behavior and inexpensive cost, the activated binary SCM can be considered an ecological and economical admixture, especially for the coalescent activation procedure.

Statistical Approach to Design Zn Particle Size, Shape, and Crystallinity for Alkaline Batteries

The modern alkaline primary battery is composed of a highly alkaline, gelled electrolyte-zinc powder anode dispersion (slurry), a cellulose-based separator, and an electrolytic manganese dioxide (EMD) cathode pellet – typically arranged in a cylindrical cell geometry. This battery system has its origins in the 1950s and thus has had decades to be researched and matured and it is known that the limiting performance of this battery system is concentrated at the slurried zinc anode. This had led many researchers to focus on the anode for improvement with most previous engineering efforts targeting enhanced performance, capacity, and stability of this material. Due to the various material fabrication processes involved with manufacturing industrial zinc powder, there exists an array of unique zinc particle size, shape, and crystallinity combinations that distinguish industrial zinc powders from one another. These industrial zinc powders are typically produced through trial-and-error processes using existing “rules of thumb”. Consequentially, it is possible that something has been missed and a data-driven approach could elucidate the optimum combination of zinc particle properties.In this study, we investigate the effect of Zn particle size, shape, and degree of crystallinity on the achievable capacity and corrosion current. Various types of zinc powders were sieved into size fraction ranges and chemically and thermo-chemically treated to control their crystallinity. The procedure for producing zinc powders of various sizes, shapes, and crystallinities led to a 64-powder Zn matrix that was then electrochemically analyzed by linear sweep voltammetry to determine the corrosion current and galvanostatically discharged to determine the achievable capacity. These experiments were done in a newly-designed, custom-built electroanalytical cell that will be described in the talk. Following the data collection, a 4k factorial statistical analysis was performed. This analysis identified which of the controlling variables have a statistically significant influence on the achievable capacity and corrosion. The statistical model was also able to provide guidance regarding the preferred particle shape. This information can be used to develop actionable procedures for battery manufacturers to create cells that are more stable, longer lasting, and have higher energy densities.

Li Pre-Doping of SiO Electrodes Using Li-Naphthalenide Solution for Next-Generation Batteries

SiO is regarded to be one of the promising anode materials to replace graphite in lithium-ion batteries (LIB) because of its higher specific capacity than graphite and better cycle stability than Si [1]. However, the large irreversible capacity is a serious problem which consumes charged capacity in vain during initial cycles. Therefore, Li pre-dope to dose Li to SiO beforehand has been proposed. In this study, our previous achievement on Li pre-doping to Si electrodes was much helpful. The highlights of the achievement are as follows [2, 3]. Li-naphthalenide (Li-NTL) was selected as a Li pre-doping agent.Li pre-doped capacity was much dependent on the solvent of Li-NTL solution.2-methyltetrahydrofuran (MeTHF) delivered the largest pre-doped capacity. Hence, we conducted this study on Li pre-doping to SiO electrodes by referring to the achievement on Si electrodes.SiO electrodes coated on Cu foil consisted of SiO, Ketjen Black, and polyimide binder in the ratio of 80 : 5 : 15 (m/m). Two types of SiO powder with an average particle size of 5 μmφwere used: carbon-coated SiO denoted as C-SiO and bare SiO which were purchased from OSAKA Titanium technologies Co., Ltd. We adopted 0.5 M NTL/MeTHF as a standard pre-doping solution based on our result of Li pre-doping to Si. SiO electrodes were confined in an air-tight cells with the pre-doping solution for 24 h to be pre-doped. The electrodes were taken out of the cells, rinsed in DMC, and used to assemble coin cells with Li counter electrodes, separators and electrolyte solution of 1.0 M LiPF6 / EC + DMC (1:1, v/v) + 10 wt% FEC. All of these processes were conducted in an Ar-filled glove box. Discharge/charge cycle test mode was constant-curent at 0.1 mA cm−2 between 0.02 and 1.5 V at 30 °C. Figure 1 shows charge/discharge performance of C-SiO electrodes with and without Li pre-doping. In Figure 1a, the OCV of the Li pre-doped electrode was as low as 0.2 V, which was much lower than that of the electrode without pre-doping, exceeding 2.0 V, and the charge capacity was nearly missing. However, the discharge capacity was not less than that of the electrode without pre-doping. This result reveals that SiO can be pre-doped effectively by Li-NTL/MeTHF, which is the same as Si. Figure 1b shows dQ/dV analysis results, in which the anodic curves for the with and without pre-doping are nearly identical. However, almost no cathodic curve is observed for the with pre-doping as shown in Figure 1a, while a sharp peak at 0.46 V assigned to formation of L x SiO y is observed for the without pre-doping [4]. A dashed curve inserted in the Figure 1b is the cathodic curve for the second cycle of the with pre-doping to complement the missing first cycle one. This curve shows no peak at 0.46 V and suggests formation of L x SiO y during pre-doping. We further analyzed the pre-doping reaction to elucidate the mechanism based on the result shown above. The detail of the results will be shown and discussed in our presentation.[1] M. N. Obrovac, V. L. Chevrier, Chem. Rev., 114, 11444 (2014).[2] M. Saito et al., s of PRiME 2020, A02-0410 (2020).[3] M. Saito et al., J. Electrochem. Soc., 166, A5174 (2019).[4] C. P. Grey et al., J. Am. Chem. Soc., 141, 7014 (2019). Figure 1

Effect of Ti and TiC additions on the microstructure and wear resistance of high chromium white irons produced by laser directed energy deposition

Laser directed energy deposition (L-DED) is an additive technology that offers a rapid solution for repairing mining components made of High Chromium White Iron (HCWI) on site. However, the refined carbide morphology from the rapid cooling in L-DED is detrimental to the wear resistance of the repairs. In this study, two types of powder (Ti powder and TiC powder) were added to improve the wear resistance of L-DED HCWI. The Ti powder addition promoted the formation of in-situ TiC while the TiC powder addition resulted in coarse ex-situ TiC and fine in-situ TiC in the as-deposited microstructure. The addition of both powders destabilised the austenitic matrix (γ-Fe). The wear resistance was investigated by a high stress abrasion test using silica sand (softer than M7C3) and a pin-on-disk wear test using a ruby pin (significantly harder than M7C3). The best wear results were achieved with 6.55 wt% Ti powder addition. This destabilised γ-Fe in the as-deposited microstructure which underwent strain-induced martensite formation during the high stress abrasion wear testing, improving the wear resistance of the alloy. The addition of TiC powder improved the wear resistance in the high stress abrasion test due to the increase in the fraction of carbide. In the pin-on-disk wear test, the alloys with TiC powder addition performed better than the cast sample because a greater amount of γ-Fe matrix in the microstructure provided a better combination of hardness and ductility.

Optimization of Densification Behavior of a Soft Magnetic Powder by Discrete Element Method and Machine Learning

Densification of amorphous powder is crucial for preventing magnetic dilution in energy-conversion parts owing to its low coercivity, high permeability, and low core loss. As it cannot be plastically deformed, its packing fraction is controlled by optimizing the particle size and morphology. This study proposes a method for enhancing the densification of an amorphous powder after compaction, achieved by mixing three types of powders of different sizes. Powder packing behavior for various powder mixing combinations is predicted by an analytical model (i.e., Desmond’s model) and a computational simulation based on the discrete element method (DEM). The DEM simulation predicts the powder packing behavior more accurately than the Desmond model because it incorporates the cohesive and van der Waals forces. Finally, a machine learning model is created based on the data collected from the DEM simulation, which achieves a packing fraction of 94.14% and an R-squared value for the fit of 0.96.

Differential regulation and preventive mechanisms of green tea powder with different quality attributes on high-fat diet-induced obesity in mice.

Tea powder has been reported to have some physiological functions. However, there is no report on whether there are differences in the active ingredients of tea powder with different qualities and whether there are different prebiotic mechanisms. This study was aimed to investigate the effects of different qualities of tea powder on preventing obesity from different aspects, namely antioxidation, inflammation, lipid-lowering, and intestinal flora, using an obesity mouse model. The results showed that all three types of tea powder with different qualities could reduce body weight and decrease serum TC, TG, and LDL-C. However, tea powder with different quality attributes exhibited diverse modulatory effects and mechanisms. Tender tea powder contained more tea polyphenols, and it had a better effect on improving oxidative stress. Tender tea powder significantly decreased the abundances of Blautia, Bilophila, and Oscillibacter, and increased the abundances of Alloprevotella, Lachnoclostridium, Romboutsia, and Ruminococcaceae_UCG-004. Coarse tea powder contained more dietary fiber, and had a better effect on reducing the food intake and improving lipid metabolism, which could reduce lipid synthesis and increase lipid β-oxidation. Coarse tea powder significantly decreased the abundance of Dubosiella and increased the abundances of the Lachnospiraceae_NK4A136 group and Coriobacteriaceae_UCG-002. Our findings provide a theoretical reference for the comprehensive utilization of tea powder.

EXPERIMENTAL INVESTIGATION ON EFFECTIVENESS OF ADDING ZEOLITE TOSODIUM BICARBONATE FIRE SUPPRESSANT POWDER

Sodium bicarbonate is commonly used fire suppressant powder because of its high efficiency and low cost. Two main factors affecting the effectiveness of sodium bicarbonate is moisture absorption and cake formation. From the literature survey, it has been found that, by adding small quantities of zeolite particles to sodium bicarbonate the above issues can be eliminated. Also, by adding zeolite the surface area available for each particle increases, which will eventually increase the efficiency. The project aims in experimenting zeolite added sodium bicarbonate fire extinguishing powder and finding out its effectiveness in suppressing. A new type of particulate fire suppressant powder was prepared, in which zeolite of different concentration are added. By the experimental results, it is found that the zeolite added sodium bicarbonate suppressant powder has better performance than the conventional sodium bicarbonate, with relatively shorter extinguishing time and a smaller number of agents required to extinguish the fire. Based on experimental study and mathematical modelling in MATLAB software it is found that the optimum concentration of zeolite in sodium bicarbonate was obtained as 7.939 percentage and extinction time was 1.125 seconds

Alkali-silica Reaction Elimination Potential of High-Performance Concrete Containing Glass Powder

This study is mainly concerned with the assumption that glass powder can eliminate the potential alkali-silica reaction in high performance concrete. Glass is often land filled, produced as a secondary raw material or as a by-product of production. Chemical analyses were carried out, and the ecotoxicity of the material was investigated, serving as a basis for testing a potential alkali-silica reaction. High performance concrete (HPC) containing different types of waste powder (secondary raw material from production (SGP), jewelry production (SGJ), container waste glass (CWG), and glass from used photovoltaic panels (GPP)) are tested according to the international standard ASTM C1260 and the Czech technical condition TP 137. Newly designed mixtures are innocuous from the ASR point of view in the most cases, except SGP HPC.