Mixed Binders Research Articles

Structure formation in gypsum-magnesia materials for laying in the developed spaces of salt deposits

The influence of the preparation method, gypsum content and liquid-solid ratio on the process of hardening and properties of mixed gypsum-magnesia binders intended for laying in the developed space of salt areas has been studied. With the introduction of fillers – waste from the development of salt deposits and plasticizers – in them, filling mixtures, which are non-linear viscoplastic thixotropic systems with a certain period of stress and strain relaxation, have been obtained. The phase composition of hardening products, electrokinetic, rheological and physico-mechanical properties of the obtained plasticized filling mixtures depending on the method of injection, the type and content of plasticizers have been investigated. At optimum liquid-solid ratio and the plasticizer content of the mixture with low static and dynamic yield stress and effective viscosity and extended setting time have been obtained.

Possibilities of ammonium ions fixation into mixed binders

The purpose of this study is to analyze the usability of ammonium ions fixation in mixed binders with the addition of high temperature fly ash. The experiment used high-temperature fly ash from operations in which the secondary flue gas denitrification methods have been implemented, specifically by the method of the selective non-catalytic reduction, known as DeNOx. The fixation of ammonium ions was performed by the addition of sodium hexanitrocobaltate(III). The study examines the influence of addition of cobalt(III) complex compound on the release of ammonia into the environment during the mixing the mixed binder. The released ammonia was quantitatively captured into the acid and subsequently titrated. The effect of cobalt(III) complex compound on the rate of hydration and mechanical properties of the mixed binders was also studied. The influence on the environment in terms of leachability was observed.

Investigation of mixing effect and molecular aggregation between virgin and aged asphalt

The mixing process of virgin and aged asphalts is the essential of the rejuvenation of recycled asphalt pavement. The molecular association of asphalt may be decomposed and reconstructed due to the intermolecular interactions while virgin and aged asphalts are blended together. This study investigated the mixing effect between virgin and aged asphalts use rotational viscometer (RV), gel permeation chromatography (GPC) and molecular simulation methods. The high temperature viscosity of the mixed binder was tested by RV, which indicates that the viscosity of the mixed binder was not a linear superposition of virgin and aged asphalt. The GPC was used to test molecular weight of virgin, aged and mixed binders. The comparison between tested and calculated GPC curves shows that the molecular weight of the mixed binder was not the superimposed of virgin and aged asphalts. The molecular simulation indicates that the asphaltene and resin molecules had a tendency of gathering together. The mixing of two asphalt binders with different chemical structures could narrow the distance between aggregated molecules.

A Model for Determining the Effective Thermal Conductivity of Porous Heterogeneous Materials

In this study, an algebraic equation is shown for determining thermal conductivity coefficient of a porous heterogeneous solid material with two components. This equation was developed based on the porosity of the material, ratio, density and thermal conductivities of its components. This equation was applied to the waste EPS aggregate and samples with cement or gypsum mixed binders. Packaging waste EPSs were collected, decomposed to particles of 0–3 mm diameter and mixed with each binder volumetrically in the ratios of 20 %, 40 %, 60 % and 80 % separately. Thermal conductivity coefficient of the samples was determined by using the hot wire method. The calculated values were 4.41 % to 26.04 % higher than the measured values in the samples with cement, and they were 5.79 % to 15.62 % higher than the measured values in the samples with gypsum. The equation was applied similarly to the samples with expanded clay and cement with pumice aggregates.

A Water‐Soluble NaCMC/NaPAA Binder for Exceptional Improvement of Sodium‐Ion Batteries with an SnO2‐Ordered Mesoporous Carbon Anode

SnO2 @CMK-8 composite, a highly promising anode for Na-ion batteries (NIBs), was incorporated with polyvinylidene difluoride (PVDF), sodium carboxymethylcellulose (NaCMC), sodium polyacrylate (NaPAA), and NaCMC/NaPAA mixed binders to optimize the electrode sodiation/desodiation properties. Synergistic effects between NaCMC and NaPAA led to the formation of an effective protective film on the electrode. This coating layer not only increased the charge-discharge Coulombic efficiency, suppressing the accumulation of solid-electrolyte interphases, but also kept the SnO2 nanoparticles in the CMK-8 matrix, preventing the agglomeration and removal of oxide upon cycling. The adhesion strength and stability towards the electrolyte of the binders were evaluated. In addition, the charge-transfer resistance and apparent Na+ diffusion of the SnO2 @CMK-8 electrodes with various binders were examined and post-mortem analyses were conducted. With NaCMC/NaPAA binder, exceptional electrode capacities of 850 and 425 mAh g-1 were obtained at charge-discharge rates of 20 and 2000 mA g-1 , respectively. After 300 cycles, 90 % capacity retention was achieved. The thermal reactivity of the sodiated electrodes was studied by using differential scanning calorimetry. The binder effects on NIB safety, in terms of thermal runaway, are discussed.

Fine-Grained Concretes on Non-Clinker Binders with Highly Disperse Mineral Components

World and domestic experience in the development of various compositions and technologies for composite and mixed binders (including cementless ones) and concretes is reduced to the use of components based on ashes of thermal power plants and other secondary mineral resources. But their qualitative, ecological and economic indicators, as well as the energy intensity of production, do not meet modern requirements.

Effects of Electrode Wettability on Discharge Capacity Li-O2 Batteries

Three kinds of customized electrodes with various wettability are fabricated in this study. Results show that electrodes containing polyvinylidene fluoride (PVDF) binder are lyophilic while the binder of polytetrafluoroethylene (PTFE) results in the lyophobicity of electrodes. The electrode with mixed wettability is composed of two lyophobic carbon coatings on top and bottom and one lyophilic carbon coating in the middle. The intermittent current (1.0 – 0 mA/cm2) strategy indicates resting Li-O2 batteries (for 10 min) between each discharge (for 5 min) to improve the oxygen transfer within the porous electrode. The lyophilic electrode has the highest increase rate of discharge capacity after applying intermittent current while the electrode with mixed wettability achieves the highest specific discharge capacity. The specific discharge capacity of the PVDF 15% electrode is 1664.8 ± 259.6 mAh/g at intermittent current but it is only 807.6 ± 137.6 mAh/g at continuous 1.0 mA/cm2. The discharge capacity is improved by 106.2%. The specific discharge capacity of Li-O2 battery with mixed binders increases from 1645.9 ± 98.3 mAh/g to 2256.7 ± 225.8 mAh/g when the operation changes from continuous discharge current to intermittent discharge current. The intermittent discharge strategy is optimized based on the mixed wettability electrode and results show that discharging at 1.0 mA/cm2 for 5 min and resting for 5 min periodically achieves highest discharge capacity. This study emphasizes that the lyophobicity of electrode and intermittent discharge strategy can both enhance the O2 diffusion and thus increase the discharge capacity of Li-O2 batteries.

Treatment of Hazardous Solid Waste Using Solidification and Stabilization Technique

The immobilization of toxic metals present in the pharmaceutical effluent treatment plant (ETP) sludge is studied using the solidification/stabilization (S/S) technique. Different mixtures of cement, lime and bentonite as binders and additives (Pulverized fuel ash (PFA), silica fume and quarry dust) are used in order to reduce the mobility of the metal constituent of the pharma sludge as well as to strengthen brick. The interaction between the S/S matrix were studied using X-ray diffraction spectroscopy (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Thermo gravimetric-Differential Thermal Analysis (TG- DTA), Unconfined Compression Strength, Toxicity characteristics leaching procedure (TCLP) tests. The results showed that the optimized composition matrix have a strong fixing capacity for heavy metal includes Cu, Zn, Fe, Co, Pb, Ni and Cd. All the specimens have been observed to be sufficient in achieving the target compressive strength of 0.3 N/mm² required for landfill disposal and mixed binders (Cement, Lime, and Bentonite) brick can be recommended for external use in construction i.e. for pave of pedestrian roads.

Soft bitumen asphalt produced using RAP

Soft bitumen asphalt concrete is a common paving material in Scandinavia. The purpose of this investigation was to indicate the possibility to compensate for the stiff binder of reclaimed asphalt pavement (RAP) by using softer binders compared to the mix design. Characterization of binder mixing and diffusion were carried out using viscosity measurements and tests on asphalt concrete comprised stiffness modulus and cyclic compression testing. Acquired results suggest that virgin and reclaimed binders mix and the viscosity can be predicted using simple mixing models. In the case of asphalt made from mixing virgin and recycled material, the mechanical properties indicates fully mixed binders and mixing occurs during sample manufacturing. In general, this study suggests that soft asphalt mixtures can be produced using RAP and that nominal binder viscosity of the final product can be obtained by compensating the stiff binder of the RAP by virgin bitumen of a softer grade.

Influence of binder characteristics on the setting and hardening of hemp lightweight concrete

Hemp concrete is an alternative building material used for insulation in low energy constructions. Experiments conducted with pure cement have generally led to poor binding properties, hence, commercial binders are often composed of a mix of hydraulic binder with lime. However, empirical observations in laboratories or onsite indicate that setting problems still may occur. This paper attempts to identify the phenomena that can explain the properties of mixed binders. With regard to hydration and mechanical performances, the results show that the addition of lime, especially fine lime, can reduce detrimental effects of hemp, but does not fully suppress them.

FBC – Ash as Principal Constituent of Mixed Hydraulic Binder

This paper deals with opportunity of FBC – ashes using for hydraulic binder preparation, and as one of the main material for preparation of mixed binders. This way prepared binder should be closed to strong hydraulic limes potentially cements of lower strength classes.

Mechanical and tribological characteristics of tungsten cermet composites sintered with Co-based and zirconia mixed binders

The influence of cobalt based and zirconia mixed binder additives on the mechanical properties and tribological characteristics of WC based spark plasma sintered cermet composites was investigated. Varied weight proportions of zirconia stabilized with yttria along with constant weights of 9Co/WC–4.5CO–2Cr–5Ni metallic binder were blended with WC, consolidated and sintered using spark plasma sintering process. The composites produced were characterized using SEM and XRD analyses, density measurements, mechanical properties and wear test evaluations. The results show that the use of the mixed binder additives did not significantly affect the densification process as relative densities above 92% (7.5% less than that achieved using only the Co based metallic binders) were achieved using SPS processing. However, the grain size was observed to increase with increase in zirconia content in the mixed bond composites, and the hardness values decreased with increase in zirconia content. The toughness and fracture toughness showed significant improvement with the addition of zirconia. Also the coefficient of friction for the mixed binder sintered composites were on the average lower than that of the cermet composites without zirconia. Pseudoplastic properties characterized by the presence of delaminations were the primary wear mechanism observed for the zirconia containing cermets; while pits and wear groove formations were observed in the cermets without zirconia.

Measurement of some particleboard properties bonded with modified carboxymethyl starch of oil palm trunk

The properties of an experimental particleboard made from rubberwood using carboxymethyl starch as a binder were evaluated for its mechanical and physical properties. Carboxymethyl starch was prepared by chemically modifying oil palm trunk starch with phosphoryl chloride. The panels produced were based on two target densities of 0.60g/cm3 and 0.80g/cm3 and four different types of binders, which were native starch, carboxymethyl starch, carboxymethyl starch mixed with 2% urea formaldehyde and urea formaldehyde as controlled samples. The starch was evaluated using X-ray diffractometry, fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analyzer, and differential scanning calorimetry. The specimens with a density of 0.80g/cm3 made using carboxymethyl starch showed an improvement in term of physical and mechanical strength compared to the panels bonded with native starch. The improvements in the properties of the panels were observed on the panels bonded using mixed binders which successfully achieved the minimum value specified by the standard.

Influences of silicone emulsion on fire protection of waterborne intumescent fire-resistive coating

The combination of self-crosslinking polyacrylate emulsion and silicone emulsion was used as a binder for the preparation of waterborne intumescent fire-resistive coatings. The influences of silicone emulsion on fire protection and char formation of the coatings were investigated in detail by means of TGA, SEM, energy dispersive spectroscopy analysis, rheological measurement, and fire protection tests. The results showed that using silicone emulsion improved thermal stability and antioxidation ability of the coating and increased the residue weights of the char layer at high temperature. Furthermore, an appropriate amount of silicone emulsion could improve the rheological property of the mixed binders and be conducive to the increase of the intumescent factor of the coatings, thus improving the fire protection of the coating significantly. However, an excess amount of silicone emulsion can lead to uneven dispersion of silicone emulsion in the mixed binder and cause an uneven distribution of cell size of the char layer.

A Novel Green Tape with High Solid Content Prepared by Aqueous Tape-Casting

Green tapes were prepared by aqueous tape-casting method with binders of polyvinyl alcohol, styrene-acrylate emulsion and the mixed binders, respectively. Effects of solid content and binders on viscosity of the slurry were investigated by digital rotary viscosimeter. Results show that solid content should be lower than 60wt % with the binder of PVA; solid content could achieve the maximum 73wt% by tape-casting using emulsion as binder. Furthermore, slurry with solid content up to 75wt % had been successfully prepared by tape-casting using mixed binders. Mixed binders are promising additives to produce high solid content green tapes with smooth surface, adequate strength and very good flexibility.

Optimal percentage of reclaimed asphalt pavement in central plant hot recycling mixture

For determining the optimal percentage of RAP material in central plant hot recycling, binder was recovered from RAP by means of Abson recovery method, and properties tests of mixed binders consisting of recovered asphalt and fresh asphalt at different ratios were performed. In addition, the performances of mixture with different percentages of RAP such as rutting resistance, anti-cracking, moisture susceptibility and fatigue resistance were tested. The binder test results showed that the high temperature performance was improved with the increase of the percentage of the RAP, while the low temperature performance was declined. When the percentage of the recovered binder was less than 30%, the mixed binder could match the technical standards for fresh asphalt. Tests on the mixtures showed that rutting resistance increased gradually as RAP percentage increased, while thermal anti-cracking at low temperature and fatigue properties declined. The effect of the percentage of RAP on moisture susceptibility was limited. It is indicated that low temperature performance and fatigue properties are important for selecting the optimal percentage of RAP. Based on data obtained from binders and mixtures, it is concluded that the maximum percentage of RAP is approximately 30% without the addition of rejuvenating agent.

Influences of binder on fire protection and anticorrosion properties of intumescent fire resistive coating for steel structure

The combination of epoxy emulsion and self-crosslinked silicone acrylate (SSA) emulsion was used as mixed binder for preparing water-borne intumescent fire resistive coating. The influences of binders on the properties and char formation of the coatings were investigated in detail by using thermogravimetry (TG), scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray fluorescence spectrometry (XRF), rheological measurement, fire protection test and anticorrosion property test. It was found that the fire protection and foam structure of the coating was significantly improved by adding 14% SSA (by mass). The TG results showed that adding SSA increased the residue weights of the coatings. The XRF results demonstrated that anti-oxidation of the coatings was improved by adding SSA into the mixed binders. The results of anticorrosion property test indicated that the anticorrosion property of the coatings was enhanced with increase of content of SSA.

Quantitative distribution patterns of additives in self-leveling flooring compounds (underlayments) as function of application, formulation and climatic conditions

The distributions of organic additives in self-leveling flooring compounds (SLCs) were investigated using laser-scanning microscopy for the selective visualization of the additives, which had been previously stained by a fluorescent dye. The distributions of latex (VC), polycarboxylate ether (PCE), cellulose ether (CE), casein (Cas) and polyvinyl alcohol (PVA, a component of redispersible powders) were analyzed in Portland (PC) and Calcium aluminate cement (CAC) dominated SLC formulations as a function of application thickness and different climatic conditions. It is shown that evaporation induced water flux through the communicating pore system causes considerable enrichments of these additives in the uppermost millimeter of the mortar layer. The resulting fractionation factors can be correlated with the different hydration kinetics of PC or CAC dominated mixed binders as well as with the drying conditions. Investigations on the additive distribution indicate that CAC dominated formulations develop more homogeneous enrichments than PC dominated systems.

Chemical and heat resistance of silicone‐acrylic‐based binder and paint system on mild steel panels

PurposeThis paper sets out to study the characteristics of silicone‐acrylic‐based resin and paint systems on mild steel panel for chemical resistance and high‐temperature applications.Design/methodology/approachSilicone resin has been incorporated into acrylic resin at various compositions. The mixed resins binders and paint systems have been characterised using physical test, acceleration test, electrochemical test and microstructure observation.FindingsThe addition of silicone resin into acrylic resin showed significant improvement against high temperature. The results showed that coating film containing at least 30 per cent of silicone resin by weight was able to withstand high temperature of at least 250°C. With the addition of titanium dioxide (TiO2) pigment into the best performing silicone‐acrylic‐based resin system, the system with pigment volume concentration of 30 per cent TiO2 showed the best performance which indicated the value of critical pigment volume concentration. The finding showed blistering formed in low‐PVC systems and rusting in high‐PVC systems.Research limitations/implicationsOwing to the environmental issue, water‐based silicone‐acrylic resins should be explored to reduce the emission of harmful organic solvent. This can be done using solventless or powder coating technique.Practical implicationsSilicone‐acrylic resin coatings are a cost‐effective high‐temperature coating that have moderate resistance against corrosive environment such as marine water and also outdoor exposure with rain/sunshine cycles.Originality/valueThe studies of this resin may give useful reference to other researchers.

Hydration Mechanisms, Microstructure, and Mechanical Properties of Mortars Prepared with Mixed Binder Cement Slurry-Asphalt Emulsion

Nowadays, deep cold recycling techniques are increasingly considered an effective method for the preventive and corrective maintenance of existing pavements. Not only are these techniques quickly performed and cost effective, but they also allow one to recycle in-place materials, thus limiting the cost of transportation. Various binders can be used for the cold recycling process, including asphalt emulsion, asphalt foam, hydraulic binders, or mixed binders. Of the latter, asphalt emulsion is most often used with the addition of a small quantity of cement (less than 2% with respect to the total mass of aggregates) to accelerate the breaking of the emulsion. This paper aims at understanding the hydration process, the microstructure, and the mechanical properties of mortars prepared with a new mixed binder made of a cement slurry and a small quantity of asphalt emulsion (SS-1 and CSS-1). Conduction calorimetry data reveal that the cement hydration process is nominally influenced by the presence of a small quantity of emulsion. Scanning electron microscope observations show the good dispersion of the asphalt droplets inside the hydrated cement paste. A cationic emulsion tends to entrain less air than anionic emulsion. Test results also indicate that the introduction of asphalt droplets inside a cement mortar matrix leads to a significant reduction in compressive strength and elastic modulus as well as a slight decrease in flexural strength. Mortars made with the cationic emulsion (CSS-1) show higher strengths and elastic modulus than mortars made with anionic emulsion (SS-1).