Wet Mixing Research Articles

Efficacy of Acacia Gum Biopolymer in Strength Improvement of Silty and Clay Soils under Varying Curing Conditions

Acacia gum (AG), a polysaccharide biopolymer, has been adopted to improve the strength of three cohesive soils by subjecting them to diverse environmental aging conditions. Being a polysaccharide and a potentially sustainable construction material, the AG yielded flexible film-like threads after 48 h upon hydration, and its pH value of 4.9 varied marginally with the aging of the stabilized soils. The soil samples for the geotechnical evaluation were subjected to wet mixing and were tested under their Optimum Moisture Content (OMC), as determined by the light compaction method. The addition of AG modified the consistency indices of the soils due to the presence of hydroxyl groups in AG, which also led to a rise in OMC and reduction in Maximum Dry Unit weight (MDU). The Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR) were determined under thermal curing at 333 K as well as on the same day of sample preparation. The least performing condition of the soil’s CBR was evaluated under submerged conditions after allowing the AG-stabilized specimens to air-cure for a period of 1 week. The UCS specimens tested after 7 days were subjected to the initial 7 days of thermal curing at 333 K. A dosage of 1.5% of AG yielded the UCS of 2530 kN/m2 and CBR of 98.3%, respectively, for the low compressible clay (LCC) after subjecting the sample to 333 K temperature for 1 week. The viscosity of the AG was found to be 214.7 cP at 2% dosage. Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and average particle size determination revealed the filling of pores by AG gel solution, adsorption, and hydrogen bonding, which led to improvements in macroproperties.

Using Biopolymers to Stabilize Collapsible Soil by Using Wet Mix Method

Using Biopolymers to Stabilize Collapsible Soil by Using Wet Mix Method

Alpha-calcium sulfate hemihydrate incorporated with tri-calcium phosphate and hydroxyapatite bioceramics as potential scaffold for bone regeneration

The development of artificial grafts, including biodegradable materials and non-biodegradable ones, for bone regeneration is a significant advance in the field of biomaterial science. Notably, bioceramics such as calcium sulfate hemihydrate and calcium phosphates have attracted extensive attention from researchers due to their natural bone-like composition. However, some requirements related to mechanical properties, resorption ability, osteoinduction and osteoconduction of each bioceramics have not been effectively controlled to make them ideal materials for bone regeneration applications. In this study, composites of β-tricalcium phosphate, hydroxyapatite, and α-calcium sulfate hemihydrate (β-TCP/HA/α-CSH) were synthesized using wet mixing method in order to create a template that degrades in sync with bone growth, offer sufficient mechanical strength during healing process, and has appropriate setting time for precise surgical application. The β-TCP/HA compositional phase with the ratio of 80/20 (% in weight) would be used for the entire study meanwhile the influence of α-CSH on the behaviour of β-TCP/HA/α-CSH composites would be investigated. The successful preparation of β-TCP/HA/α-CSH composite was evaluated by FTIR, XRD, and SEM. In vitro testing has further demonstrated the commendable biodegradability of β-TCP/HA/α-CSH composites and its ability for cell adhesion and migration, suggesting that β-TCP/HA/α-CSH composites would be a promising biomaterial for bone engineering.

The influence of Multi-Layer Plastic Packaging (MPP) on the high-temperature performance of asphalt binders and mixtures using wet and dry mixing methods

ABSTRACT High temperatures, combined with heavy traffic loads, increase the risk of permanent deformation and reduce the useful lifespan of pavements, leading to a greater need for maintenance and rehabilitation activities throughout the pavement's service life. This study aims to evaluate the effectiveness of recycled thermoplastic additives, specifically Multi-Layer Plastic Packaging (MPP) materials, in enhancing the high-temperature performance of asphalt mixtures. MPP materials, including types such as Polyester, Polyethylene, Nylon, and Metalized Polyester, were used for binder modification in asphalt mixtures. The modification was conducted using both wet and dry methods. The physical and rheological properties of the modified binders were assessed at high temperatures to determine their impact on stiffness and resistance to permanent deformation. The results indicate that MPP materials significantly improve the high-temperature performance of asphalt mixtures by enhancing binder stiffness and resistance to permanent deformation, with the wet method proving more effective than the dry method. These findings highlight the need for developing practical guidelines for incorporating MPP materials in asphalt production in the future and underscore the importance of comprehensive studies on maintenance, rehabilitation, and overall pavement lifecycle costs.

Investigation and prediction of impact of aggregate size and shape on porosity and compressive strength of pervious concrete

ABSTRACT Pervious concrete is proven to environmentally benefit urban pavement construction. Optimising compaction energy evidently reduces uncertainty in the mass production of pervious concrete with uniform characteristics. The distribution of compaction energy in wet mix and rearrangement of binder-coated aggregate particles are affected by the size and shape of aggregates. This study analyses the impact of aggregate size and shape on porosity and compressive strength prediction from mix-design parameters. Aggregate-to-cement ratio (3, 4 and 5), compaction (0, 30 and 60 blows from standard Proctor rammer), aggregate sizes (5–12 mm, 12–18 mm and 18–25 mm) and aggregate shape (0, 200 and 1000 revolutions of milling in Los Angeles Abrasion Value) were used to cast a total number of 486 samples. Constituents were mixed in an electrically powered drum of capacity 96 L, for 20 min. Porosity was computed from constituent ratios (theoretical porosity) and apparent weight (measured porosity). The compressive strength of samples was recorded using a Universal Testing Machine. The measured porosity and theoretical porosity relationship was significantly affected by the shape of the aggregate and not by the size. Modified Ryshkewitch’s model predicted compressive strength from porosity, aggregate-to-cement ratio, compaction and aggregate size and shape with an accuracy of 0.92 (R2). Two of six arbitrary constants depended on aggregate shape and size.

High-value application of kaolin by wet mixing method in low heat generation and high wear-resistant natural rubber composites

In this study, a silane coupling agent and kaolin, a natural mineral resource, were introduced into the wet mixing process of natural rubber latex, the high wear-resistant and low-generation heat natural rubber composites were prepared. The sputtering, collision, and deposition of coupling agent/fillers/natural rubber latex mixed emulsion onto the roller effectively could break up the filler aggregates, enable fillers to be better infiltrated, distributed, and dispersed in the rubber. The effects of dry/wet mixing processes and the ratio of kaolin to silica on the crosslinking density, filler dispersion, extrusion rheological properties, gas barrier properties, dynamic mechanical properties and thermal stability of NR composites were investigated, and the silanization mechanism was summarized by FTIR and XRD. The experimental results showed that kaolin improved the crosslinking density and failure temperature, reduced the Payne effect, extrusion swell, and rolling resistance. Compared with 60 phr silica-filled natural rubber, the gas barrier property and wear resistance of 60 phr kaolin-filled natural rubber were improved by 64 % and 27 %, respectively, and the rolling resistance was reduced by 57 %. When the ratios of silica to kaolin were both 20:40, the crosslinking density, gas barrier property, and wear resistance of wet mixing were improved by 24 %, 45 %, and 9 %, respectively, compared with dry mixing. This study provided a new method for the high-value application of kaolin in wet mixing and green tires.

Study on the effect of wet mixing process on the properties of EPDM rubber/fiber/hollow glass microsphere composite system

Study on the effect of wet mixing process on the properties of <scp>EPDM</scp> rubber/fiber/hollow glass microsphere composite system

Application of wet carbon black masterbatch in green mining radial tires

AbstractIn the context of environmental protection and energy consumption reduction, reducing the rolling resistance of mining machinery tires is one of the important methods to achieve the goal of green mining. This study probes the effects of wet mixing with a wet carbon black masterbatch on the rolling resistance and grounding performance of wide‐body vehicle tire treads by investigating the cross‐linking structure, rubber–filler (R–F) interaction force, and physicomechanical properties of the wet mixing rubber compounded with a wet carbon black masterbatch. The results indicate decreases in the maximum torque‐minimum torque difference, cross‐link density, and R–F interaction of the wet mixing rubber and increased filler–filler (F–F) interaction and carbon black dispersion. Meanwhile, the tensile elongation of the wet mixing rubber increases, its DIN abrasion property improves, and its Tanδ decreases at 60°C. A numerical method to estimate tire steady‐state rolling resistance is also developed. Finite element simulation analysis reveals that the steady‐state rolling resistance of the wet mixing rubber is reduced by 7.04% at 100% standard load, and its grounding performance is enhanced. By proposing a method to reduce the rolling resistance of tires, this study also provides a reference for the development of wide‐body vehicle tires.Highlights Explored the filler interaction of wet mixing rubber. Explained the low energy loss of wet mixing rubber. Proposed a new finite element method for calculating tire rolling resistance.

Study on design optimization, road performance verification and preparation process selection of hybrid fiber reinforced asphalt mixture composite

To achieve long-lasting, high-strength, and sustainable asphalt pavement, this study prepared a hybrid fiber asphalt mixture using micron-scale calcium sulfate whiskers (CSW) and millimeter-scale basalt fibers (BF). The response surface method was employed to optimize the mix design, develop a prediction model, and verify road performance. The preparation process was refined based on the optimal mix design. The findings revealed that the best overall road performance was obtained with 5 % CSW content, 6 mm BF length, and 0.32 % BF content. The mixture demonstrated optimal performance with CSW wet mixing and BF dry mixing. Additionally, testing the fiber asphalt mixture at the mixture level was found to be crucial, as results can vary from those obtained at the mastic level. This study provides an in-depth analysis of the hybrid fiber asphalt mixture’s action mechanisms in material optimization, performance verification, and preparation processes, offering valuable insights for related research and engineering applications of hybrid fibers.

Wear characteristics of a CNTs reinforced aluminium composited fabricated by the solution mixing process

Aluminium-carbon nanotube (Al-CNT) composites have proven to offer a lot of potential for applications involving friction and wear. This study investigated the wear behaviour of Al-CNT composites with uniformly dispersed CNTs without structural damage at concentrations of 0.5 wt%. The wear behaviour of these composites has been compared with that of pure aluminium, which was fabricated using the identical wet shake mixing, compaction, and extrusion procedure. The study aimed to determine how CNT concentration and applied stress influence the wear behaviour of composite materials. Scanning electron microscope (SEM) was used by the researchers to examine the surface features of the worn samples. The study showed a significant increase in hardness and wear resistance with adding CNT. Compared to pure aluminium, the composite containing 0.5 wt. % CNTs demonstrated a 25% reduction in wear rate, and the average value of the coefficient of friction (µ) also decreased. The wear rate and coefficient of friction increased when samples containing 0.5 wt. % CNTs were subjected to various loading scenarios. The major contribution of CNTs to improving wear characteristics was discovered through SEM investigation of these worn surfaces. Using the ANSYS Workbench, a built finite element model was used to perform contact analysis on the disc and pin. Analytical results and experimental data were contrasted, and the ANSYS data was utilised to assess the process parameters. The comparison confirmed the analysis accuracy and dependability, which showed a consistent agreement between the analytical findings and the experimental results.

Research Progress of Natural Rubber Wet Mixing Technology.

The performance of natural rubber (NR), a naturally occurring and sustainable material, can be greatly enhanced by adding different fillers to the NR matrix. The homogeneous dispersion of fillers in the NR matrix is a key factor in their ability to reinforce. As a novel method, wet mixing technology may effectively provide good filler dispersion in the NR matrix while overcoming the drawbacks of conventional dry mixing. This study examines the literature on wet mixing fillers, such as graphene, carbon nanotubes, silica, carbon black, and others, to prepare natural rubber composites. It also focuses on the wet preparation techniques and key characteristics of these fillers. Furthermore, the mechanism of filler reinforcement is also examined. To give guidance for the future development of wet mixing technology, this study also highlights the shortcomings of the current system and the urgent need to address them.

Comparative study on microstructure evolution, mechanical properties, and wear behavior of TiC and B4C single-reinforced and hybrid-reinforced Al–Mg–Si alloys by vacuum hot-press sintering

To explore the variances between single-reinforced and hybrid-reinforced Al–Mg–Si alloys with TiC and B4C, 10 wt.%-(TiC + B4C)/6061Al, 10 wt.%-B4C/6061Al, 10 wt.%-TiC/6061Al and 6061Al were prepared via wet mixing for 8 h followed by vacuum hot-press sintering at 580 °C and 30 MPa for 2 h. Microstructure evolution, mechanical properties, and wear behavior were investigated in this study. The results show that unlike single reinforcement of TiC, single reinforcement of B4C and hybrid reinforcement of TiC and B4C altered the distribution of Si and facilitated the in-situ formation of SiC. Both single reinforcement and hybrid reinforcement resulted in mixed fracture characteristics of ductile fracture and cleavage fracture, while hybrid reinforcement of TiC and B4C demonstrated superior strength and plasticity matching. At equivalent particle mass fractions, single reinforcement of TiC was more conducive to inducing recrystallization during sintering, followed by single reinforcement of B4C, and hybrid reinforcement of TiC and B4C had the least effect. At equivalent particle mass fractions, single reinforcement of B4C had the most significant effect on improving the wear resistance, followed by hybrid reinforcement of TiC and B4C, and single reinforcement of TiC had the least effect. All particle addition methods demonstrated a mixed wear mechanism involving abrasive wear, adhesive wear, and spalling wear. This study provides valuable insights into the development of aluminum matrix composites.

Radiation shielding properties of shotcrete containing different aggregates

In this study, the physical and mechanical properties of wet mix shotcrete produced using crushed stone aggregate (CS), ferrochrome slag aggregate (FS), and barite (B) aggregate have been investigated. Furthermore, the radiation shielding properties have been determined experimentally, theoretically, and through simulation. A control sample was produced using 50 % CS and 50 % FS. Subsequently, shotcrete groups were produced by substituting B aggregate at replacement rates of 25 %, 50 %, 75 %, and 100 % instead of FS. The mechanical properties such as density, ultrasonic pulse velocity (UPV), compressive strength, flexural strength, and splitting tensile strength of the produced spray concrete groups were investigated. Additionally, experimental radiation shielding measurements were conducted using a high-purity germanium (HPGe) detector system with emissions from four different radioactive sources (133Ba, 137Cs, 60Co, and 22Na) spanning nine different gamma energies ranging from 276.5 to 1332.5 keV. As a result of the experimental measurements, the linear attenuation coefficients (μ) of the shotcrete samples were obtained. A proportional increase in μ was determined with increasing barite content. Using the experimental mass attenuation coefficient (μ/ρ) results, half-value layer (HVL) and tenth-value layer (TVL) thicknesses, as well as mean free path (MFP) values, were calculated. An increasing B aggregate ratio did not have a significant effect on the μ/ρ value, while an increase was observed in the HVL, TVL, and MFP values. Moreover, the WinXCOM interface was employed for theoretical calculations, and the FLUKA Monte Carlo code was utilized for simulation calculations. The obtained data were compared with experimental results, revealing a good agreement between them. Based on the obtained data, it was concluded that increasing the B aggregate ratio resulted in improvement in mechanical properties compared to the control sample, and additionally, it was determined that B aggregate-added shotcrete is an effective gamma radiation shielding material.

Investigation of ferrochrome slag utilization in wet mix shotcrete: Mechanical strength and radiation shielding performance

In this study, wet-mix shotcrete specimens were produced by substituting natural aggregate (NA) with ferrochrome slag aggregate (FS). Volumetrically, the amount of NA was reduced by 25%, 50%, 75% and 100% and a corresponding amount of FS aggregate was added. The physical, mechanical, durability and radiation shielding properties of the specimens were analysed. The gamma radiation performance was determined using energies 133Ba, 137Cs, 60Co and 22Na (ranging from 276.5 keV to 1332.5 keV) and a high-purity germanium HPGe detector system. The neutron radiation performance of the shotcrete specimens was obtained using FLUKA simulation. The WinXCOM interface was used for theoretical calculations, while the FLUKA Monte Carlo code was used for simulation calculations, and the data obtained were compared. It was observed that shotcrete mixtures having up to 50% ferrochrome slag aggregate showed a significant increase in mechanical properties. In radiation shielding performances, linear attenuation coefficient (μ), half-value layer (HVL), Tenth-value layer (TVL), mean free path (MFP) and radiation protection efficiency (RPE) parameters increased with increasing ferrochrome slag aggregate ratio, while mass attenuation coefficient (μ⁄ρ) values remained almost constant. It was experimentally determined that the 5 cm thickness shotcrete produced had RPE values of 75% and 50% at low (276.4 keV) and high (1332.5 keV) energies, respectively. It was concluded that the use of 50% ferrochrome slag aggregate has a positive effect on the mechanical properties of shotcrete mixtures. Additionally, ferrochrome slag-reinforced shotcrete is a good gamma and neutron radiation shielding material.

Preparation of ablation-resistant ethylene propylene trioxide/polyimide staple fiber composite insulation layer by solution wet mixing process

This research developed a solution wet mixing process for creating Ethylene propylene diene monomer/polyimide staple fiber composites (EPDM/PISF), overcoming the uneven fiber distribution seen in traditional dry mixing techniques. By uniformly dispersing PISF within the EPDM matrix, the wet mixing process improves the composite's performance. This is evidenced by an 18.08 % reduction in ΔG′, a 14.29 % lower linear ablation rate (0.042 mm/s), enhanced thermal stability, a higher charring rate, and a denser carbonized layer. Optimal overall performance was achieved using a PISF content of 10phr in the wet mixing process. This advancement significantly enhances the ablation resistance of EPDM/PIS, making them a promising choice for high-performance and durable insulation in solid rocket motors.

A Facile Scalable Strategy for Constructing Novel Robust Self‐Healing Glove Utilizing Nanoreinforced Thermoreversible Carboxylated Nitrile Butadiene Rubber

AbstractRecent decades have seen an increase in using self‐healing technology in fabricating multifunctional rubber materials, which incorporate intrinsic mechanisms. However, achieving commendable self‐healing efficiency while maintaining strength in thin rubber films remains challenging. Herewith, the preparation of self‐healing carboxylated nitrile butadiene rubber thin films is presented with 0.40 ± 0.05 mm thickness, reinforced with sustainable TEMPO‐oxidized cellulose nanofibers. The thin films are fabricated using wet mixing and casting methods and translated to prototype fabrication via dipping. The study involves the effect of varying zinc stearate and filler concentrations on healing efficiency via ionic mechanisms alongside other characterization techniques, such as chemical composition, surface morphology, cross‐link density, and thermal stability. The fabricated thin films exhibited a tensile strength of 5.38 MPa and an elongation‐at‐break of 518%. After undergoing a temperature‐induced healing process at 100 °C for 1 h, the healing efficiency for both properties reached 72% and 90%, respectively. Moreover, these films demonstrates the ability to heal repeatedly at the same fracture site over multiple cycles, maintaining a healing efficiency of over 45% after the third cycle. A glove prototype is fabricated and tested using water and air leakage tests to prove the self‐healing technology's successful transfer.

Enhanced Resistance to Desiccation Cracking of Polymer-Bentonite Mixtures: An Experimental Investigation of Underlying Mechanisms

Polymers have been shown to enhance the resistance of swelling clay soils to desiccation cracking, a critical property in engineering applications, particularly in waste containment facilities. However, the microscopic and macroscopic mechanisms driving this improvement remain poorly understood. Additionally, the influence of different mixing methods on these mechanisms is not well-established. While dry mixing is more convenient for onsite implementation, wet mixing offers intercalation between clay and polymer, resulting in potentially more durable stabilization outcomes. In this paper, key properties related to desiccation cracking of a polymer-clay mixture were measured. The mixture was synthesised by amending Na-bentonite with sodium carboxymethyl cellulose (Na-CMC) using dry and wet mixing. Soil water retention characteristics curves (SWCC), swelling and shrinkage potential, tensile strength, and pore size distribution by mercury intrusion porosimetry (MIP) were measured for both mixtures and untreated bentonite. Compared to pure bentonite, mixtures were found to have slightly reduced air-entry values, significantly lower swelling and shrinkage potentials and higher tensile strengths. In all experiments, dry mixing exhibited superior performance compared to wet mixing. MIP analysis of the amended mixtures revealed a more porous structure when compared to untreated bentonite.

Storage stability of model infant formula powders produced under varying wet-mix processing conditions

Wet-mixing processes can be tuned to reduce energy consumption, although impacts on quality and stability should be addressed. This work evaluated the effect of wet-mix processing (total solids, TS: 50 or 60%; heat treatment: 75 or 100 °C × 18 s) and storage conditions (open package: 25 °C, 58% RH, 4 weeks; closed package: 25 °C, multilayer bag, 12 weeks) on the physicochemical stability and digestibility of infant formulas. Processing significantly influenced the physicochemical characteristics of the powders, with TS exerting a stronger impact than heat treatment. Powders produced from 60% TS wet mixes presented the fastest water sorption, which accelerated lactose crystallisation and fat liberation. Formulas in closed packages were stable for 12 weeks. While lactose crystallised before week 2 in open-package storage, inducing major physical changes, only limited effects were observed on digestibility. These findings provide valuable insights to ensure consistent quality during shelf-life of infant formula.

Enhancing interface adhesion between waterjet‐produced rubber powders and natural rubber by wet‐mixing method

AbstractThe addition of rubber powder (RP) to natural rubber (NR) matrix using the dry mixing method leads to uneven distribution and poor interface bonding while the wet mixing method is not feasible due to the hydrophobic nature of the RP surface. To address this issue, we developed a method for producing RP with weakened hydrophobicity on the surface by high‐pressure waterjet and successfully achieved even distribution of the waterjet‐produced rubber powders (WPRPs) in NR and strong interface adhesion between WPRPs and NR by the wet mixing method. The properties of NR/WPRP composites were tested and characterized carefully. When adding 6 phr of 140‐mesh WPRPs in the NR matrix, the tensile strength and elongation at break of the NR/WPRP composites were 30.2 MPa and 627.2%, respectively, which were 4% and 7% higher than NR without WPRPs. Moreover, the anti‐abrasion property of the NR/WPRP composite was also strengthened by the addition of WPRPs. Our findings demonstrate that recycling waste rubber through a reasonable recycling method can not only reduce material waste and alleviate environmental pollution but also enhance the performance of the raw rubber, which offers significant economic benefits.

Influence of mixing technique on properties of Li1.3Al0.3Ti1.7(PO4)3 solid electrolyte prepared by the solid-state reaction - A comparison of dry 3D mixing technique with wet ball-milling

Li1.3Al0.3Ti1.7(PO4)3 (LATP) NASICON(Na Super Ion Conductive)-type solid electrolyte is prepared using conventional wet ball-milling and dry 3D mixing techniques to investigate the influence of mixing technique on properties of LATP. The mixing techniques influence impurity formation of calcined LATP powder. Thus, sintering behavior of the calcined powders is also affected by the mixing technique, i.e. LiTiPO5 formation is confirmed in the ball-milling samples and Li-ion conductive Li4P2O7 is main impurity in the 3D mixing samples. The influence is not limited to impurity formation. Uniform grains are observed in the 3D mixing pellet, contrarily, non-uniform sintering occurs in the ball-milling sample. As a result, the 3D mixing pellets demonstrate higher Li-ion conductivity than the ball-mill samples. The dry 3D mixing technique, which can omit drying process, is promising for LATP preparation owing to simplification of preparation process and a formation of high Li-ion conductive LATP pellets. Also, this study clearly shows that the mixing techniques affect ionic conductivity of the sintered LATP significantly, emphasizing importance of mixing procedure in the solid-state reaction.