Dry Mixing Method Research Articles

A Study on using Plastic Coated Aggregate for evaluation of modified Bituminous Concrete Mix

Road network system of India is deteriorating day by day due to rapid increase in traffic and improper maintenance. This paper aims to shed light on the use of plastic coated aggregate (PCA) in bituminous concrete (BC) and analyze PCA’s efficiency using various tests in eco-friendly way to achieve efficiency in economical manner. The major advantage of using PCA to construct pavement in sustainable way is by reduction in usages of bitumen and also improve the properties of aggregate. Dry mix (DM) method was adopted to mixed the waste plastic by utilizing shredded waste plastic bottles made of Polyethylene Terephthalate ( PET) in bituminous mixes. The physical properties of traditional aggregate and PCA were also compared. The Marshall blend was prepared by using bitumen grade 80/100, PCA, stone dust and cement as a filler to make BC Grade -2. The aggregates used for prepared total mix coated with PET content of 3 %, 5%, 7%, 9% and 11% by weight of optimum binder content. To find out its suitability in field, Marshall stability, flow value and volumetric characteristics of mix were determined and compared to traditional bituminous concrete mixtures (without plastic). PCA had better binding property, less water absorption, and higher Marshall Stability value was also shown in the results, and is a better option to solve environment pollution due to plastic waste.

Evaluating the role of uniformity on the properties of B4C–SiC composites

Fully dense boron carbide-silicon carbide composites were successfully produced by spark plasma sintering method at 1950 °C under 50 MPa applied pressure. The effect of dry and wet mixing methods on uniformity was observed. Density, elastic modulus, microstructure, Vickers hardness and fracture toughness were evaluated. The results showed that dry mixing did not provide uniformity on composites properties. On the other hand wet mixing provided uniformity in microstructure and consistency in material properties. The hardness of the sample containing 50 wt% B4C was measured to be 30.34 GPa hardness value was found at 50 wt% B4C content sample. The increase in the B4C content of the composites decreased the Young's modulus, shear modulus, bulk modulus and fracture toughness. The highest values were found at 10 wt% B4C sample which were 415 GPa (E), 177 GPa (G), 209 GPa (K), and 2.89 MPa m1/2 fracture toughness (KIc).

Consolidation Behavior of Clay Supported by Soil-Cement Column

This paper presents the compression and consolidation behaviors of clay supported by soil-cement column. A series of consolidation tests was performed on kaolin samples supported by soil-cement column with the ratio between diameters of column and soil sample () ranging from 0 to 0.4. All samples with soil-cement column were cured for 28 days under the vertical pressure of 25 kPa. The sample preparation techniques simulating dry deep soil mixing method was developed. The test results showed the elastic region expanded with increasing value of . However, there was no effect of on deformation behavior in the elasto-plastic region. Moreover, the value of was considered constant over the range of testing stress level, for the value of of 0 and 0.2. For the value of of 0.3 and 0.4, the values of in the elastic region was greater than that in elasto-plastic region.

NANO - SILICA (SiO2) CONTRIBUTION TO MECHANICAL AND MICROSTRUCTURAL CHARACTERISTICS OF HIGH PERFORMANCE CONCRETE PAVEMENT

High performance concrete pavement appears to be the best choice for layer with high strength and low cost. In this paper, the mechanical properties were investigated which considered essential for design and requirements of rigid highway pavement. These properties were examined by compressive strength, flexural strength and modulus of elasticity. Previous test investigations were imposed for concrete mixes with different Nano SiO2 (size of 30 nm) percentage (0, 0.5, 1,1.5, & 2) % by wright of cement as mineral admixture. Also, X- Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) tests were conducted to indicate the chemical composition of the used admixture. Energy Dispersive Spectroscopy (EDS) was conducted to visualize the micro structural behaviour of concrete during hydration process. Wet and dry mixing methods were utilised to prepare the modified concrete mixes and the results of the more effective method, were adopted. Scanning electron microscopy (SEM) was utilized to investigate the microstructure and morphology of nano concrete mixes. The results of SEM indicated that the microstructural distribution of C-S-H gel were comparable for all the nano mixes. The decrease in thickness of nano concrete layer was associated with the increment in the percentage of nano silica add to the mixes when the other factors remain the same. The best percentage of nano silica was 1.5% by weight of cementitious materials (by using dry mixing method). This percentage satisfied all requirements of fresh and hardened concrete mixes for highway pavement and achieved well microstructure with significant decrement in the thickness of concrete layer which positively reflected on construction cost.

On the processing properties and friction behaviours during compaction of powder mixtures

ABSTRACT Iron-based powder mixtures were prepared by dry and wet mixing method. The friction properties during compaction were tested by measuring the internal and external friction coefficient. The test results showed that the wet mixing process could realise the homogeneity of lubricant and improve the processing properties of the powder mixtures. With 0.6 wt-% lubricants, wet mixing powder mixtures have a flow rate of 29.6 s/50 g, an apparent density of 3.18 g cm–3, a repose angle of 35.5°, and the friction coefficient during the compaction is 0.223. An equation to calculate the total (both internal and external) friction forces during the compaction process is proposed, and then the factors influencing the friction coefficient during compaction were quantitatively analysed.

Influence of Iron Furnaces Slag on Collapsibility and Shear Strength of Gypseous Soil

Gypseous soil is one of the soils that suffer from problems and suffers from a reduction of shear strength and collapse when exposed to water immersion or water filtration in it. Many researchers have tried to solve these problems in different ways and by using many materials as additives to improve the performance and efficiency of this soil. In this research, the behavior of soil with a high content of gypsum (61.49%) is examined, using iron slag which is a by-product of the iron making process in melting furnaces, used as an additive in proportions (2, 4, 6, 8, 10., 12) %, by dry mixing method with soil. Tests are carried out to determine the effect of this substance on the shear strength parameters. The effect of water immersion on soil cohesion (c) is reduced until it reaches (c) in the case of immersion a value very close to the value in the dry state at slag ratio (10) %. This is the optimum ratio of slag to improve the value of (c). Whereas for the value of (ø), with the increase of the slag rate for both wet and dry cases, the value of (ø) increases, where (ø) reaches the highest value at; the slag rate (10) % for the dry state, and the slag rate (8) % for the soaked case. Whereas for the collapse potential (Cp), adding the slag reduces the value of the soil collapse potential (Cp), from (10.6) to the soil without additives until (0.95) for the slag rate (12) %. Then the soil becomes problematic soil.

Improvement of Electrical Conductivity of Polyamide 6/Polyaniline Blends by Graphene

Polymer composites of polyaniline (PANI)/polyamide 6 (PA6) blends and reduced graphene oxide (rGO) were prepared via the in situ synthesis method in order to improve formability and electrical properties. Polymer blends and composites were characterized by the Fourier transform infrared spectroscopy, scanning electron microscopy, and thermal gravimetric analysis. It was found that the composites prepared by the in situ synthesis method have better compatibility between polymer blends and matrix than that prepared by the conventional dry-mix method as investigated by scanning electron microscope (SEM). The Fourier-transform infrared (FT-IR) spectrograms indicate the presence of covalent bonds between functional groups between polyaniline and reduced graphene oxide. The PA6/PANI-rGO films show the electrical conductivity of 2.970×10-6 S/cm while PA6/PANI-GtO show electrical conductivity of 4.082×10-7 S/cm. Thermal stability of polymer blend was characterized by the thermogravimetric analysis. The thermal stability of polyamide 6 after blending is not changed significantly.

Effect of MWCNTs’ Content on the Properties of Polyimide Composite Molding Materials

A series of MWCNTs/PI composite molding powders with different MWCNTs contents were prepared by ultrasonic dispersion in situ polymerization and blending method, and the samples were prepared by molding. In this experiment, 3, 3’, 4, 4’ - biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA) and 4, 4’ - diaminodiphenyl ether (ODA) are taken as the main raw materials and MWCNTs as reinforcement materials. The molecular structure, thermal stability, mechanical properties, wear resistance and hardness of the composites were characterized. Results showed that mechanical properties of the composite molding materials prepared by ultrasonic dispersion in situ polymerization are better than those prepared by dry mixing method. The composite molding materials showed the best properties at the MWCNTs content of 0.5wt%. What’s more, the tensile strength and elongation at break are 108.9MPa and 4.5%, which are 26% and 23.6% higher than those of pure PI.

The effect of crystalline material addition to concrete quality

To improve the moisture susceptibility of concrete structure that will be exposed to water, an admixture should be added. One of the additives that can be added is Xypex C-1000 NF, which a crystalline material. A number of past studies have shown that this additive is effective in improving the moisture resistance of concrete structure. However, the application of this additive in Indonesia was found to be challenging as the performance of the concrete mixture was not as good as expected. This research aims to evaluate the effect of adding various percentages of this additive, various amount of water to be added to the concrete mixture, and the methods of mixing the materials, which are wet and dry methods, by looking at both the slump value and the compressive strength of the concrete specimens. From the research results, it was found that the methods used to mix the additive matter to produce a desirable concrete quality. The wet mix method is the preferable method as it produces less variations in compressive strength test results regardless of the additional water amount. It was also found that, by using both dry and wet mix methods, the usage of Xypex C-1000 NF can improve the compressive strength value.

Influence of the production method on the thermophysical properties of high temperature molten salt-based nanofluids

The potential use of molten salt-based nanofluids as thermal energy storage material in Concentrated Solar Power plants has gained attention over the last years due to their enhanced storage capacity. The possible effects of the salt-based nanofluid production at industrial scale have not been yet investigated, as this could influence the nanoparticles agglomeration and therefore their thermal and flow properties. Four methods were evaluated for the production of solar salt-based nanofluids containing 1 wt% of silica nanoparticles. The particle size distribution, the stability, the rheological behaviour and the specific heat of the samples were measured. Nanofluids prepared by means of a dry mixing method presented the lowest viscosity, trimodal particle size distribution and lack of stability. The commonly used dissolution method coupled with oven drying in a petri dish as well as the ball milling method presented non-Newtonian behaviour and intermediate values of particle size and stability. The new spray drying method proposed provided a monomodal particle size distribution with high stability but the highest viscosity and shear thickening behaviour. Results suggest that the four methods evaluated are appropriate for specific heat enhancement (up to 21.1%) but a commitment between stability and viscosity has to be achieved.

Reinforced concrete mixture using abaca fiber

This research study discusses the reinforcement of concrete mix design using abaca fiber. The process of mixing the abaca fibrous concrete used in this mixing is the dry mixing method. The addition of abaca fiber to concrete mixture was done with abaca fiber composition with fiber variation: 0%; 0.15%; 0.20%; 0,25% and variation of fiber length: 25 mm; 37.5 mm; 50 mm. The specimens of cylindrical material (100mmx200mm) and beam (100mmx100mmx400mm), are tested after the test object reaches the age of 28 days in the Universal Testing Machine (UTM) and are evaluated through the ASTM standard in compressive strength test, splitting tensile strength and flexural strength. The addition of fibers significantly affects the physical properties of the concrete, when the fiber increases the slump value will be smaller so the mixture becomes more difficult to mix. The results obtained by the abaca fiber concrete mixture for the composition (0.15%) and the ideal fiber length (50 mm) by providing an optimum value increase in the compression test of 12.61%, 72.64% tensile test, 98.98% flexural test of the normal concrete mixture.

Effect of nano-TiO2 content on the flexural strength and compressive strength of dry-Mixing CDG-Slag based geopolymer paste

In this paper, the effects of nano-titanium dioxide (TiO2) content on the 28-day flexural strength and 28-day compressive strength of Completely decomposed granite (CDG) and slag based geopolymer paste was investigated, using the dry-mixing method. The calcium hydroxide, sodium carbonate and solid sodium silicate were used as the alkali activator. The results show that with the increase of nano-titanium dioxide content increasing from 0 to 2.0%, the compressive strength and flexural strength gradually increase. In addition, the surface of geopolymer paste gradually became smooth. What’s more, the geopolymer paste microstructure was characterized by using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray (EDX) Microanalysis, details of the research process and analysis are presented throughout the paper.

High-Ni cathode material improved with Zr for stable cycling of Li-ion rechargeable batteries.

The Zr solvent solution method, which allows primary and secondary particles of LiNi0.90Co0.05Mn0.05O2 (NCM) to be uniformly doped with Zr and simultaneously to be coated with an Li2ZrO3 layer, is introduced in this paper. For Zr doped NCM, which is formed using the Zr solvent solution method (L-NCM), most of the pinholes inside the precursor disappear owing to the diffusion of the Zr dopant solution compared with Zr-doped NCM, which is formed using the dry solid mixing method from the (Ni0.90Co0.05Mn0.05)(OH)2 precursor and the Zr source (S-NCM), and Li2ZrO3 is formed at the pinhole sites. The mechanical strength of the powder is enhanced by the removal of the pinholes by the formation of Li2ZrO3 resulting from diffusion of the solvent during the mixing process, which provides protection from cracking. The coating layer functions as a protective layer during the washing process for removing the residual Li. The electrochemical performance is improved by the synergetic effects of suitable coatings and the enhanced structural stability. The capacity-retentions for 2032 coin cells are 86.08%, 92.12%, and 96.85% at the 50th cycle for pristine NCM, S-NCM, and L-NCM, respectively. The superiority of the liquid mixing method is demonstrated for 18 650 full cells. In the 300th cycle in the voltage range of 2.8–4.35 V, the capacity-retentions for S-NCM and L-NCM are 77.72% and 81.95%, respectively.

Reversible photochromic photocatalyst Bi2O3/TiO2/Al2O3 with enhanced visible photoactivity: application toward UDMH degradation in wastewater

1,1-Dimethylhydrazine (UDMH) and its by-products were considered carcinogenic toxins and represent a serious health hazard to the population once present in water under natural conditions without treatment. The conventional degradation method suffers from incomplete removal of intermediate products (especially N-nitrosodimethylamine (NDMA)), the powdery catalysis being difficult to recover and results in high energy consumption. In this study, a series of Bi2O3/TiO2/Al2O3 (BTA) photocatalysts have been successfully synthesized by a simple dry mixing method with powder material followed by their immobilization. It was evaluated by the photocatalytic degradation of UDMH present in wastewater, which can be recovered by rapid filtration and utilizes only solar energy. The catalyst exhibited markedly enhanced photocatalytic activity for the degradation of UDMH wastewater compared with conventional TiO2/Al2O3 (TA) catalysts under UV, visible and solar irradiation. Besides, the intermediate NDMA was gradually completely degraded. The photocatalysts were extensively characterized using scanning electron microscopy, energy dispersive spectrometry, specific surface area (BET), X-ray diffraction, X-ray photoelectron spectroscopy, UV–visible diffuse reflectance spectroscopy and photo-electrochemical I–t curves evaluation. The results revealed that all the BTA composites exhibited high stability and stronger absorbance in visible light. In addition, the BTA exhibited a reversible photochromic property that can effectively expand the range of light absorption and enhance the photocatalytic activity. The reversible photochromic properties of BTA explained in the proposed mechanism model are expected to be useful for detecting and sensing UDMH or other organic contaminants.

Usage of powder pinus brutia cone and colemanite combination in brake friction composites as friction modifier

Friction composites are materials used in places such as braking systems of highways and rail transportation vehicles. Composites that are resistant to abrasion and environmental conditions such as temperature and humidity and with high resistance to friction are preferred in brake systems. Therefore, friction composites are formed by the combination of many materials with different properties. In this study, five friction composite samples were prepared with various combination of powder Pinus Brutia cone and colemanite. The amount of other ingredients of samples are constant. Samples were produced by conventional dry mixing method. Friction and wear tests were determined by a full-scale brake friction tester. The specific wear rate, friction coefficient and friction stability parameters of the samples were investigated and friction performance was evaluated. The hardness of the samples was calculated by Brinell hardness tester and the density was determined according to Archimedes' principle. According to the test results, all samples are compatible with the literature, applicable in industry and comply with the standards.

Distribution of ASR gel in conventional wet-mix glass mortars and mechanically produced dry-mix glass blocks

The alkali-silica reaction (ASR) of recycled glass mortars prepared by the traditional wet-mix and the mechanically compacted dry-mix methods using a same aggregate-to-cement (A/C) ratio was examined based on the ASTM C1260 accelerated mortar bar test method. The test results showed the expansion values of the dry-mix glass blocks were within the threshold of ASTM C1260 while the wet-mix glass mortars were above the threshold. The mercury intrusion porosimetry (MIP) results of the dry-mix blocks showed a new peak in the larger pore size range between 10 µm and 100 µm in the differential curves, and the porosity in this ranges decreased after the ASR test. As revealed by scanning electron microscopy-backscattered electron (SEM-BSE) image analysis, the mitigation of ASR expansion and the decrease of porosity were mainly due to the distinctive different distribution of ASR gel in the dry-mix blocks. Compared to the ASR gel formed within the glass aggregate in the wet-mix mortars, the ASR gel in the dry-mix blocks was mainly observed on the surface of glass aggregates in the larger pores (between 10 and 100 µm). No ASR gel was observed in the interface between the glass aggregates and the cement paste of both the wet-mix mortars and the dry-mix blocks. The release of the swelling pressure of the ASR gel by the large pore in the dry-mix blocks suppressed the further development of cracks caused by ASR expansion.

Graphene-enhanced ABS for FDM 3D printing: effects of masterbatch preparation techniques

3D printing technologies have received a lot of attentions because of the high flexibility of the process as well as the capability of producing complex shaped and high detailed artifacts with ease. This study focuses on the development of acrylonitrile butadiene styrene (ABS)/graphene composite materials, which can be used as a filament for the melt extrusion 3D printing or FDM 3D printing technique. Since the dispersity of graphene in the polymer matrix is the key parameter of controlling the properties of the composites, the ABS/graphene masterbatches with high concentration of graphene were produced via three techniques: dry mixing; solvent mixing and coagulation techniques. The obtained high concentration ABS/graphene masterbatches were then mixed with pure ABS and melt extruded to produce ABS/graphene composites filament with 1 wt% of graphene. The ABS/graphene composites preparing via solvent mixing and coagulation were found successfully 3D printed. The dry mixing method brought about the aggregation of graphene particle and failed the print.

A novel green approach for the preparation of high performance nitrile butadiene rubber-pristine graphene nanocomposites

Present article scrutinizes the effect of pristine few layers graphene incorporation into NBR matrix via a green approach in terms of mechanical properties and two different fabrication routes viz. latex casting and latex casting followed by dry rubber mixing. Large scale production of pristine few layers graphene was accomplished by means of planetary ball milling and was characterized using X-ray diffraction (XRD), Raman spectroscopy and Transmission electron microscopy (TEM) analysis. The produced graphene and procured MWCNT was then successfully incorporated (separately) into NBR latex. It was found out that at a particular filler loading of 3 phr for latex casting method, 5 phr for dry rubber mixing method and only 0.4 phr for MWCNT based samples the produced nanocomposites demonstrated a significant increment in tensile properties. However, when only the supernatant from the 3 phr graphene dispersion was used, the sample showed an improved increment (363%) in mechanical properties due to the removal of other bulk particles during settling which might otherwise act as stress concentrators inside the composite. The demand for multifunctional elastomers is increasing now a day and hence these findings where pristine graphene has been successfully and uniformly incorporated into NBR matrix (an important synthetic elastomer with huge applications) would be scientifically significant.

VERTICAL PERMEABILITY OF DREDGED SOIL STABILIZED WITH FLY-ASH BASED GEOPOLYMER FOR ROAD EMBANKMENT

This study presents the vertical permeability and strong relationship of dredged soil stabilized with fly-ash based geopolymer which is to be used for constructing road embankments. The fly-ash used for this study was a low-calcium (Class F) fly-ash. The varying effects on both properties due to the different partial replacements of geopolymer were studied. 10%, 20%, and 30% of the soil sample’s mass were used as a partial replacement. The samples were prepared using the dry-mix method and subjected to 28 days of air-dried curing. Tests like the unconfined compressive strength test and the falling head permeability test were conducted. The morphological features of the samples were investigated using the scanning electron microscopy (SEM). The test results showed that as the percentage replacement of geopolymer increases, the samples become less permeable. SEM analyses confirmed the results, showing that the geopolymer tends to cover up the pore spaces of the soil, causing the water to have fewer passageways.

Modification of the dry method for mixing crumb rubber modifier with aggregate and asphalt based on the binder mix design

Mechanical characteristics of the asphalt binders and mixtures were enhanced by utilising modifiers. The crumb rubber modifier has been introduced to the asphalt modification as an environmentally friendly procedure of scrap tires, to improve the mechanical characteristics of the asphalt. This study aims to modify the dry method for mixing crumb rubber modifier with asphalt and aggregate based on the binder mix design. To achieve this goal crumb rubber modified asphalt mixtures were prepared and tested by applying various tests such as Marshall Stability test, indirect tensile strength test, and wheel tracking test. Three mixing methods of CRM were studied regarding evaluating the stability, rutting, and moisture susceptibility. The crumb rubber modifier dry mixing method was modified and named the complex process. Better results were achieved for enhancing mechanical properties.