Binder Content Research Articles

Al2O3/SO3 molar ratio of PG-CAC-based binders on the macro-micro properties of cement-treated waste dredged clay

The binders promoting the generation of ettringite (AFt) are very suitable for stabilizing waste dredged clay (DC) with high water content, while the variability of components may lead to uncertain workability. In this study, a series of unconfined compression tests were conducted on the DC stabilized by the ternary hydration system consisting of ordinary Portland cement, recycled phosphogypsum and calcium aluminate cement, the effects of the Al2O3/SO3 molar ratio (m) on the mechanical properties were evaluated accordingly. Subsequently, a series of microstructure tests and mineralogical tests were performed to further reveal the influence of m on the mechanism of stabilized DC. The results demonstrate that at the same binder content, the unconfined compression strength (UCS, qu) shows a linear increase with m. The compactness of cement-treated DC was improved by the main generation of ettringite, while excessive ettringite may cause expansion and destroy the existing cementation. As m increases, the excessive Al2O3 promotes the generation of C-(A)-S-H and C-A-H after generating enough AFt, which not only cements the soil particles with the cementation effect, but also repairs cracks induced by the AFt expansion. The collaborative effects of the filling and cementation result in an improvement of qu from 11.2% to 129.5% when m increases from 0.133 to 1.414. It can be anticipated from the study that controlling m around 0.55 will play an important role in stabilizing the DC, thus further promoting the co-utilization of recycled DC and phosphogypsum.

Disposal of pine wood waste by pelleting with sulphate soap binder

AbstractPromising method for disposal the pine wood waste through extrusion pelleting using sulphate soap as a natural binder is considered in the article. Prior to pelleting, the wood waste requires drying to a water content of no more than 10%. Analysis of pine wood waste drying in filtration mode yielded optimal parameters: a 20 mm layer thickness, temperature of 135 °C, and drying time of 3,900 s. The optimal content of sulphate soap binder was determined to be about 20%, resulting in reduced coke residue, increased volatile components, higher calorific value, and enhanced static strength. This binder facilitates formation of pellets at lower pressures, increases calorific value, and acts as a lubricant, reducing friction and associated energy costs.

Macroscopic and Microscopic Investigation of Gypsum Slag Cement-Stabilized Recycled Aggregate Base Layers.

The purpose of this study is to investigate the macro and micro properties of stabilized recycled aggregate base layers using gypsum slag cement (GSC) and compare them with ordinary Portland cement (OPC). To achieve this, four levels of recycled aggregate content (0%, 50%, 60%, 70%) and three levels of binder materials (3.5%, 4.5%, 5.5%) were designed, where the binding materials included OPC and GSC. When GSC is used as the binding material with 0% recycled content, two scenarios for the ratio of slag to activator are considered: 4:1 and 4:2. For recycled content of 50%, 60%, and 70%, only the 4:1 ratio is considered. The macro-mechanical properties of the composite material were studied through compaction tests, unconfined compressive strength tests, and indirect tensile strength tests. Microscopic properties were investigated through X-ray diffraction (XRD) and scanning electron microscopy (SEM). Macroscopic test results indicate that, at an equal binder content, GSC exhibits a higher moisture content and maximum dry density compared to OPC. Moreover, the unconfined compressive strength and indirect tensile strength of GSC are higher than those of OPC. Microscopic test results reveal that the hydration products of both binding materials are essentially similar; however, under identical curing conditions, the hydration products of GSC are more abundant than those of OPC.

Antifungal Susceptibility Assessment of Innovative and Non-Conventional Lime Mortars Incorporating Almond-Shell Powder Bio-Waste Subjected to Particle-Dispersion Technique.

A favorable environment for fungi colonization in building materials' surfaces can emerge when certain hygrothermal conditions occur. Thus, reducing fungal growth susceptibility is of major interest. Furthermore, if the integration of bio-wastes is performed in parallel with the development of innovative materials for this purpose, a more sustainable and environmentally friendly material can be obtained. In this study, the fungal susceptibility of lime mortars incorporating almond-shell powder (ASP) microparticles (2 and 4%, wt.-wt. in relation to the binder content) was evaluated. The particle-dispersion technique was employed to prepare the bio-waste introduced in the mixtures. The fungal susceptibility of ASP samples was compared with nanotitania (n-TiO2) with recognized antifungal properties. Mechanical strength, water absorption, and wettability tests were also performed for a better characterization of the composites. Although the addition of 2% ASP led to mechanical properties reduction, an increase in the compressive and flexural strength resulted for 4% of the ASP content. Difficulties in fungal growth were observed for the samples incorporating ASP. No fungal development was detected in the mortar with 2% of ASP, which may be correlated with an increase in the surface hydrophobic behavior. Furthermore, mortars with ASP revealed a reduction in water absorption by capillarity ability, especially with 4% content, suggesting changes in the microstructure and pore characteristics. The results also demonstrated that an improvement in the physical and mechanical properties of the lime mortars can be achieved when ASP microparticles are previously subjected to dispersion techniques.

Compressive strength of manganese fine-grained material and molasses briquettes regarding binder content and curing time

In the production of raw materials for the manufacture of ferroalloys, up to 50% of the material mined is discarded as fine-grained tailings. Those tailings are deposited in dams, which are considered an environmental liability. To avoid this, an alternative would be to agglomerate the tailing dam materials using the briquetting process. Therefore, this work aims to evaluate the compressive strength of briquettes made of manganese fine-grained material (with particle size < 2.00 mm) and molasses regarding curing time and percentage of binder. To achieve the objective, 45 briquettes were made with fine-grained manganese ore, with 3 different molasses content (binder), these were put into 3 weeks of curing, to analyze the impact of binder content and curing time. The result was that the longer the curing time, the better the compressive strength and that increasing binder content reduces its compressive strength. Finally, the best results were obtained with 5 % binder and 3 weeks of curing time, in which the agglomerate produced had a compressive strength of 9,0 MPa.

Alternative hydraulic concretes based on calcium sulfate-granulated blast furnace slag composites

Two series of hydraulic concretes were prepared with alternative and sustainable composite binders of mineral calcium sulfate hemihydrate or waste anhydrite fluorgypsum, both supplemented with granulated blast-furnace slag, and fly ash or silica fume. The mixtures with 300 and 400 kg m−3 of binder cured for up to 360 days showed strengths of up to 30 MPa and hydraulic character. The microstructural configuration, characterized by SEM, EDS and XRD, indicated that the precipitated framework of gypsum crystals was stable under water after being engulfed by C–S–H like products formed by the reactions of the slag, pozzolanas and Portland cement. Ettringite was identified and assumed in moderate amounts in some samples, indicating the sulphatic activation for the slag and fly ash. The environmental impact assessed by a simple LCA indicated that the studied concretes release GHG in average 64.6 or 81.3 kgCO2eq·m−3 depending on the binder content, which is up to 5.3 times lower relative to conventional Portland cement mixtures. Depending on the distances travelled, freight was an important factor of GHG, while grinding and sieving were very low.

Ultrasonic welding of lap joints of PEI plates with PEI/CF-fabric prepregs

In this study, ultrasonic welding (USW) of lap joints of polyetherimide (PEI) plates (adherends) with carbon fiber (CF) prepregs impregnated with PEI was investigated. No energy director (ED) was used, so binder contents were varied in the prepregs to compensate for the lack of the polymer in the fusion zone. In addition, the effect of the USW parameters on the structure and the mechanical properties of the lap-joints were analyzed. The most homogeneous macrostructure, the maintained structural integrity of both the CF-fabric in the prepregs and the lap-joined PEI adherends, as well as the maximum strength properties (tensile strength) were revealed for the USW joints with the minimum polymer content in the prepreg. In this case, rising the USW time from 400 up to 800 ms radically changed the macrostructure of the fusion zone, while the strength properties did not vary significantly (shear stresses were 42–48 MPa). Computer simulation of the influence of the PEI/CF-fabric ratios in the prepregs on the deformation response of the USW joints showed that the prepreg thicknesses and, accordingly, the PEI/CF ratios did not exert a noticeable effect on the strain–stress (tensile) diagrams, while the determining factor was the adhesion level.

Using the shakedown theory to study the cyclic behaviour of an unreinforced and fibre-reinforced stabilized soft soil

ABSTRACT When a material is subjected to cyclic loading, there are changes in the material’s geomechanical behaviour that need to be characterized for a safe design. For unbounded granular materials, the shakedown theory is used to explain the soil’s behaviour under cyclic loading. However, it is not clear yet if such theory is extendable to unreinforced and fibre-reinforced stabilized soils. To this end, a series of unconfined compression cycling loading tests were performed, to study the effect of the number of cycles and initial deviatoric stress level on the behaviour of an unreinforced and reinforced stabilized soil. The results were analysed in terms of shakedown theory, elastic and plastic deformation energy and damping ratio. It was observed that shakedown theory seems to represent the behaviour of the stabilized unreinforced and fibre-reinforced soils under cyclic loading, with threshold between the plastic shakedown and the plastic creep shakedown behaviour at around an absolute axial strain 1 × 10–3. The effect of increasing binder content (from 12 to 39%), comparable to reducing the initial deviatoric stress level (from 85 to 15%), promoted a reduction in plastic deformation (from 2.09 to 0.19% without fibres, and 2.21 to 0.24% with fibres) and damping ratio (from 25.17 to 10.01% without fibres, and 29.18 to 15.95% with fibres) due to the lower degradation of the solid matrix. It also promoted an increase in the difference between elastic and plastic energy (from − 1.04 to 13.92 kJ/m3 without fibres, and − 1.68 to 10.19 kJ/m3 for the first cycle).

Magnetic Force Dilatometry of Silicon-NMC622 Lithium-Ion Coin Cells: The Effects of Binder, Capacity Ratio, and Electrolyte Selection

Operando cell expansion measurements on Si-NMC622 coin cells using a magnetic dilatometer were performed to understand the effects of electrode binder content, electrode formulation, negative-to-positive electrode capacity ratio (N/P ratio), and electrolyte selection on reversible and irreversible cell expansions. Our experiments reveal a complex relationship between cell properties, imparted by the selected cell parameters, and cell expansion. Reversible cell expansions scaled with cell discharge capacity and electrode mechanical properties, while irreversible cell expansions were sensitive to capacity fade, silicon utilization, and electrolyte decomposition mechanisms. Additionally, volumetric cell energy densities were calculated using the measured capacities and irreversible expansions over the life of the cells. We show that judicious selection of cell parameters can improve volumetric energy density after 200 charge/discharge cycles by approximately two-fold. Our work provides valuable insight, at an early stage of cell development, towards minimizing the effects of cell expansion on battery cell, pack, and module designs.

The Rate Capability Performance of High-Areal-Capacity Water-Based NMC811 Electrodes: The Role of Binders and Current Collectors

The aqueous processing of cathode materials for lithium-ion batteries (LIBs) has both environmental and cost benefits. However, high-loading, water-based electrodes from the layered oxides (e.g., NMC) typically exhibit worse electrochemical performance than NMP-based electrodes. In this work, primary, binary, and ternary binder mixtures of aqueous binders such as CMC, PAA, PEO, SBR, and Na alginate, in combination with bare and C-coated Al current collectors, were explored, aiming to improve the rate capability performance of NMC811 electrodes with high areal capacity (≥4 mAh cm−2) and low binder content (3 wt.%). Electrodes with a ternary binder composition (CMC:PAA:SBR) have the best performance with bare Al current collectors, attaining a specific capacity of 150 mAh g−1 at 1C. Using carbon-coated Al current collectors results in improved performance for both water- and NMP-based electrodes. This is further accentuated for Na-Alg and CMC:PAA binder compositions. These electrodes show specific capacities of 170 and 80 mAh g−1 at 1C and 2C, respectively. Although the specific capacities at 1C are comparable to those for NMP-PVDF electrodes, they are approximately 50% higher at the 2C rate. This study aims to contribute to the development of sustainably processed NMC electrodes for high energy density LIBs using water as solvent.

Formulation in a drop - Templated granulation and compaction analysis

Binder-powder interactions were investigated using single drop penetration on pharmaceutically relevant static powder beds. Experimental effects included polymer binder type, binder concentration, drug load, and pre-wetting of the powder bed. These screening effects are relevant to formulations requiring binder granulation, especially challenging formulations having high levels of micronized active ingredients. Interactions were explored using dynamic droplet imaging to measure drop penetration, contact angle, and drop diameter. The structure of the templated granules was analyzed via uniaxial compaction, focusing on the intermediate range of the compaction curve (granule deformation and closure of interstitial porosity in the compact). The results provide guidance in pharmaceutical formulation including the dynamics of granule formation and resulting compaction behavior. The approach is especially useful for early-stage development when only small quantities of drug substance are available.

Deep learning-based online image analysis of the water suspension granulation process for 1,3,5-trinitro-1,3,5-triazacyclohexane-based polymer-bonded explosives

Polymer-bonded explosives (PBXs) are typically prepared via water suspension granulation (WSG). However, few studies have reported on online monitoring during WSG. In this study, the WSG process for 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX)-based PBXs was monitored using online imaging and infrared detection technology. The images of the particles and droplets obtained during the WSG process were then identified by employing the Mask Region-based Convolutional Neural Network (Mask R-CNN). The characteristic peak of ethyl acetate identified in the online infrared spectra during the WSG process is a key indicator for binder concentration. The experimental results show that the changes in the particle size distribution and particle morphology of the explosive modeling powders are consistent with the actual results, online infrared detection can provide effective guidance for the addition of the binder solution. This new and effective approach can be used to study WSG and has considerable potential for process optimization and quality control.

Hydrogen-Assisted Thermal Treatment of Electrode Materials for Electrochemical Double-Layer Capacitors.

The capacitance of electrode materials used in electrochemical double-layer capacitors (EDLCs) is currently limited by several factors, including inaccessible isolated micropores in high-surface area carbons, the finite density of states resulting in a quantum capacitance in series to Helmholtz double-layer capacitance, and the presence of surface impurities, such as functional groups and adsorbed species. To unlock the full potential of EDLC active materials and corresponding electrodes, several post-production treatments are commonly proposed to improve their capacitance and, thus, the energy density of the corresponding devices. In this work, we report a systematic study of the effect of a prototypical treatment, namely H2-assisted thermal treatment, on the chemical, structural, and thermal properties of activated carbon and corresponding electrodes. By combining multiple characterization techniques, we clarify the actual origins of the improvement of the performance (e.g., > +35% energy density for the investigated power densities in the 0.5-45 kW kg-1 range) of the EDLCs based on treated electrodes compared to the case based on the pristine electrodes. Contrary to previous works supporting a questionable graphitization of the activated carbon at temperatures <1000 °C, we found that a "surface graphitization" of the activated carbon, detected by spectroscopic analysis, is mainly associated with the desorption of surface contaminants. The elimination of surface impurities, including adsorbed species, improves the surface capacitance of the activated carbon (CsurfAC) by +37.1 and +36.3% at specific currents of 1 and 10 A g-1, respectively. Despite the presence of slight densification of the activated carbon upon the thermal treatment, the latter still improves the cell gravimetric capacitance normalized on the mass of the activated carbon only (CgAC), e.g., + 28% at 1 A g-1. Besides, our holistic approach identifies the change in the active material and binder contents as a concomitant cause of the increase of cell gravimetric capacitance (Cg), accounting for the mass of all of the electrode materials measured for treated electrodes compared to pristine ones. Overall, this study provides new insights into the relationship between the modifications of the electrode materials induced by H2-assisted thermal treatments and the performance of the resulting EDLCs.

Enhancing multi-objective mix design for GGBS-based geopolymer concrete with natural mineral blends under ambient curing: A Taguchi-Grey relational optimization

Rising populations and industrial expansion necessitate sustainable alternatives to conventional cement-based concrete. Geopolymers, with their impressive mechanical properties, eco-friendliness, and potential for waste utilization, offer a promising solution. Yet, concerns like rapid setting and low workability limit their widespread adoption. This study addresses these challenges by optimizing a geopolymer concrete incorporating ground granulated blast furnace slag (GGBS) blended with bentonite and dolomite minerals. Employing the Taguchi method, we optimized the mix design considering key factors like binder content, mineral replacements, alkaline-to-binder ratio, and solution ratios. Grey-Relational Analysis identified the optimal mix with 10 % bentonite and dolomite replacement, a 0.55 alkaline-to-binder ratio, 12 M NaOH solution, and 425 kg/m3 cementing materials. This optimized mix exhibited significantly improved setting times, enhanced workability, and the highest compressive strength among all tested mixtures. Experimental validation confirms its effectiveness, highlighting its potential as a sustainable alternative. Importantly, this research explores GGBS as a replacement for commonly used Fly Ash, further advancing sustainable construction practices.

Mass-composite activation energies for recycled binder blends

Using reclaimed asphalt pavement (RAP) has become an appealing development for economic and environmental benefits. One of the key issues when incorporating RAP materials is to ensure the performance of recycled binder blends. Despite extensive researches dealing with physical and chemical aspects, concerns about recycled materials combinations remain. This paper focuses on the kinetics of aging, cracking and healing process for blended binders with a novel hypothesis of mass-composite activation energies. Firstly, four blends were prepared with different ratios of virgin bitumen and laboratory-produced RAP binders. Then, Fourier-transform infrared spectroscopy was utilized to track the carbonyl formation in all samples initially and with aging, and aging activation energy (Eacr) was computed in terms of Arrhenius equation. Thirdly, strain-controlled oscillatory measurements were conducted; moreover, representative energy change rates of dissipated pseudo strain energy and recoverable strain energy were obtained to determine the activation energy for cracking (Eac) and healing (EaH), respectively. Finally, hypotheses of mass-composite activation energies were validated with the test results. It shows that Eacr of recycled binder blends are smaller than that of RAP binders, indicating a lower kinetic barrier to oxidation reaction for blended bituminous system. With the increase of RAP binder content, the blends exhibit a decrease in Eac and an increase in EaH, which reveals the adverse effect introduced by oxidation in cracking resistance and healing capability. Excitingly, the measured activation energies of recycled binder blends are consistent with the calculated mass-composite activation energies, which will hopefully provide support for performance estimation.

Influence of the material properties and the process parameters on the ablation behavior for the laser structuring of the diffusion media for fuel cells

Hydrogen-powered polymer electrolyte membrane fuel cells (PEMFCs) show promising potential to power a wide range of mobile and stationary applications and to reduce greenhouse gas emissions significantly. In PEMFCs, the oxygen transport and the water transport are essential for a long lifetime and high-performance characteristics. The diffusion media (DM), located between the bipolar plate and the catalyst-coated membrane, is a crucial component of the fuel cell that significantly affects the cell-internal processes. Usually, the DM is a two-layer material system consisting of a microporous layer based on carbon black particles coated onto a porous gas diffusion layer (e.g., carbon paper). The properties of the microporous layer regarding the water transport at high current densities and, consequently, the fuel cell’s performance and lifetime can be improved by laser structuring. Within this work, different microporous layers with varying binder content and porosities were structured by locally ablating the material using ultrashort-pulsed laser radiation in the infrared wavelength range. The effect of varying process parameters was additionally investigated. Furthermore, the ablation efficiencies were calculated for increasing pulse repetition rates to qualify a process window for an industrial structuring process. The size of the micro-drillings and the heat-affected zone surrounding the hole were evaluated through topographic and microstructure analyses using a laser scanning microscope and a scanning electron microscope with energy-dispersive x-ray spectroscopy. The results showed a rather small influence of the porosity and composition of the microporous layer on the ablation behavior. In contrast, the laser structuring parameters influenced the micro-drilling geometry significantly.

Silica Fume-Red Mud Based Geopolymer Stabilized Organic Soil

Organic soil presents significant challenges for construction due to its unsuitability as a soil type, often necessitating stabilization using conventional agents like cement. The Silica Fume (SF)-Red Mud (RM) binder mix emerges as a promising alternative stabilizer due to its low carbon footprint coupled with its superior strength-enhancing properties. In this study,we explore the feasibility of employing SF-RM based geopolymer to stabilize organic soil. To activate the collected samples, a solution of sodium hydroxide (NaOH) with molarity (M) of 6, 9, and 12 were utilized, as well as binder (SF + RM) proportions of 10%, 20%, 30%, and 40% relative to dried organic soil and alkali-to-binder (A/B) proportions of 0.5, 0.7, and 0.9, respectively. The experimental results reveal that a variety of factors, including NaOH molarity, A/B proportions, pH, and curing duration, have an effect on the unconfined compressive strength (UCS) of treated organic soil. The best combination was obtained with a binder concentration of 30%, a NaOH molarity of 9M, and an A/B proportion of 0.7. After 28 days of curing, the UCS of the treated organic soil (1714 kPa) was found to be 168 times that of the untreated organic soil (10.2kPa). Further, the production of compounds such as aluminium silicate, sodium aluminosilicate, and potassium aluminosilicate, which have been found by X-ray diffraction (XRD) research, can be ascribed to the increase in strength. Furthermore, when subjected to analysis through Field Emission Scanning Electron Microscopy (FESEM), it becomes evident that these items play a pivotal role in filling the voids within the soil-binder composite. As a consequence, they facilitate the creation of a more smoother, compact and denser structure.

Rheological and tribological properties of native potato starch agglomerated by fluidized bed granulator

We explored the rheological and tribological properties of potato starch agglomerated with a sugar binder (maltodextrin or lactose) at various concentrations by using a fluidized bed granulator. The magnitudes of consistency index and apparent viscosity of agglomerated potato starch (APS) decreased as the binder concentration was increased. Moreover, APS with a sugar binder showed lower viscoelastic moduli and higher tan δ values compared to APS with water as the binder (the control). The gel strength of all agglomerates decreased as the sugar concentration was increased. All samples showed anti-thixotropic behavior, and especially, APS with 20 % lactose showed a small anti-thixotropic area. Utilizing the Arrhenius equation clearly elucidated the effect of temperature on the apparent viscosity of all the samples. Although the maltodextrin concentration had little influence on the activation energy of APS, it increased as the lactose concentration was increased. APS samples with a sugar binder showed greater friction coefficient values compared to the control, with maltodextrin having a significant impact. The findings indicate that the rheological and tribological properties of APS rely on the type and concentration of sugar binder.

Workability of low-density polyethylene modified asphalt mixtures: A statistical analysis of particle kinematics

The utilization of recycled plastics in asphalt pavements has gained considerable attention due to its economic, environmental, and engineering benefits. However, incorporating plastics into asphalt mixtures poses challenges to their workability, sometimes leading to a detrimental impact on engineering performance. To address this limitation, this study introduces an innovative analytical approach to examine the impact of Low-Density Polyethylene (LDPE) and its processing techniques on the workability of the asphalt mixture. A particle-size wireless sensor, SmartKli, was utilized to collect the particle kinematic behaviors during compaction. The effect of various mix designs or production methods on the mixture's workability was determined by statistically analyzing the sensing data, including Two One-Sided T-tests and one sample T-test. In this project, seven mixtures with various asphalt content, and LDPE dosage were studied. The recycled plastic-modified asphalt (RPMA) was produced using two dry processing methods and one wet processing method. The results validate the significance of asphalt content on the mixture's workability. A linear correlation was observed between the active asphalt content and the mixture's workability, even in the presence of plastics. Under the identical mix design, the wet processing method proved more effective than the dry methods in integrating LDPE, as evidenced by the workability of the RPMAs. For asphalt mixtures with plastics, ensuring sufficient binder content is essential for maintaining workability, particularly in RPMAs processed via dry methods.

Synthesis of granulated Li1.33Mn1.67O4via two antisolvent methods for lithium adsorption from gas-produced water

Gas produced water is an accompanying wastewater in the natural gas extraction process, and it’s a potential liquid lithium resource contains a considerable amount of lithium. This paper investigated the feasibility of using manganese-based ion sieves to adsorb and extract lithium from gas produced water. And we focused on the applicability of two different granulation methods and extrusion and droplet in gas produced water systems. Two types of H1.33Mn1.67O4 particles were prepared by extrusion method (EHMO), and by droplet method (DHMO). The porosity of DHMO was much higher than that of EHMO, and the adsorption performance of DHMO increased with the decrease of binder concentration. DHMO prepared with binder concentration of 0.14 g·ml−1 exhibited the best adsorption performance in gas produced water, and the Li+ adsorption capacity could reach 25.14 mg·g−1. In gas produced water, the adsorption equilibrium of DHMO only took 9 hours, and the adsorption process conformed to the Langmuir model and pseudo-second-order kinetic model. The pore diffusion model (PDM) could well describe its adsorption process. Besides, DHMO showed a great selectivity to Li+, and the selectivity order of DHMO in gas produced water was Li+>Ba2+>>Mg2+, Ca2+, Sr2+>>Na+>>K+, and after 20 cycles, the Li+ adsorption capacity was still higher than 17.30 mg·g−1, and the rate of manganese dissolution was less than 1%.