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Improving asphalt mixtures has become increasingly important due to the rise in traffic volume, high maintenance costs, and the challenges associated with their implementation. Previous studies have examined various additives and modifiers. This study investigated the effect of nano Al2O3 on two significant potential damages in asphalt pavements: low-temperature cracking and moisture sensitivity. The results of this study can be used to propose a suitable solution to minimize the probability of these failures occurring in asphalt pavements. Moreover, this study examined the impact of loading modes, temperature, and crack type on the fracture toughness of asphalt mixtures. In addition to exploring pure mode I and pure mode II, four distinct mixed modes (I/II) were also studied because, usually, this mode is the critical mode of the asphalt mixture. Temperature was another variable observed to validate the elasticity of asphalt mixtures at low temperatures. Lastly, the study investigated the effect of incorporating nano Al2O3 on the fracture toughness of the asphalt mixture under different temperatures and crack geometries. To achieve the objectives of this study, the semicircular bending and indirect tensile tests were conducted. The results showed that adding 0.6% nano Al2O3 can increase the crack resistance of asphalt mixtures by up to 12%. Additionally, the study demonstrated that incorporating 0.6% nano Al2O3 can decrease the vulnerability of asphalt mixtures to moisture by 5.1%. The response surface method technique was employed to analyze the laboratory data statistically. A reduced cubic model was utilized to assess the relationship between independent factors (loading mode, temperature, crack type, and nano Al2O3 content) and fracture toughness due to its superior fit with the laboratory results Next, sensitivity analysis was used to find the effect value of each parameter on the fracture toughness of the asphalt mixture. The sensitivity analysis results showed that the loading mode, temperature, crack type, and use of nano Al2O3 , respectively, will significantly impact the fracture toughness of the asphalt mixture. [ABSTRACT FROM AUTHOR]

Nano powder mixed electrical discharge machining (NPMEDM) is an advanced thermo-physical process. It is used to create complex, precise shapes in hard-to-machine materials, such as nickel-based alloys like Inconel 718, due to their mechanical properties. This study introduces magnetic field assistance to improve the discharge state. Nano aluminum oxide was added to biodegradable soybean oil, serving as the insulating fluid to machine Inconel 718 alloy. The study examined the impact of machining parameters, including current, pulse on time, powder concentration, and magnetic field assistance, on outcomes like white layer thickness, material removal rate, and tool wear rate. Minitab software facilitated a general full factorial multi-level design to analyze the results. Findings showed that adding nano Al2O3 with a magnetic field is crucial in enhancing process performance. The lowest white layer thickness achieved was 20.59 µm, showing a 54.32% improvement. The highest material removal rate was 13.259 mm3/min, with an increase of 42.193%. The tool wear rate also improved; the minimum value was 0.0228 mm3/min, reduced by about 80.44% compared to using no powder in the dielectric fluid. Optimal settings to enhance performance were found to be a current of 8 A, pulse on time of 100 µs, powder concentration of 4 g/l, and a magnetic field intensity of 0.2 T.

The affinity towards utilisation of Glass Fiber Reinforced Polymers (GFRPs) is its exceptional and distinctive properties. These are substitutional to conventional materials with added benefits upon incorporation of filler materials into the glass/epoxy polymer composites. The present work focused in order to prepare hybrid S-Glass nanocomposite samples with a mix of nano Al2O3 (1.0 Wt% to 3.0 Wt%) and nano perlite powder (3.0 Wt% to 9.0 Wt%) with different weight percentages. According to the Response Surface Methodology (RSM) and its experimental design, the hybrid S-glass/Al2O3/Nano perlite composite was prepared using hand layup process. Further, the fabricated samples were processed as per ASTM standards and the mechanical characteristics were investigated. Thus, the responses Tensile strength and Flexural strength were recorded, optimised using RSM and anlysed using Analysis of Variance (ANOVA). Also, statistical techniques were applied to verify the experimental results. The optimal weight percentages of nano Al2O3 powder and nano Perallite powders are 2% for obtaining maximum tensile strength and 3% to obtain maximum flexural strength, respectively. The water absorption test was carried for obtained optimal sample and water uptake pattern has been recorded as per ASTM D570. [ABSTRACT FROM AUTHOR]

The study reported herein investigates the effectiveness of nano aluminum trioxide (Al2O3) as a bituminous binder modifier. The study assesses the high- and intermediate-temperature performance of bituminous binders modified with three different percentages (0.5%, 1%, and 2%) of nano Al2O3. A field emission scanning electron microscope was utilized to study the dispersion of nano Al2O3 in bituminous binder. Fourier transform infrared spectroscopy analysis was used to understand the nature of the interaction between nano Al2O3 particles and bituminous binder. Different rheological approaches, like the Superpave rutting parameter, multiple stress creep and recovery test, and time-temperature sweep, were used to study the high-temperature performance of nano Al2O3 –modified bituminous binders. All the methods undertaken in the current study to evaluate rutting susceptibility showed that nano Al2O3 showed modified binders had a very low propensity to accumulate permanent deformation. Fatigue performance evaluated using the Linear Amplitude Sweep test showed that the incorporation of nano Al2O3 enhanced fatigue performance. Nano Al2O3 –modified bituminous binders were found to be storage stable as revealed by the storage stability test. The high-temperature thermal stability of the bituminous binders measured using thermogravimetric analysis showed an improvement after nano Al2O3 incorporation. [ABSTRACT FROM AUTHOR]

One promising insight to extended service life of cement mortar and improve it is durability by assimilating nano mechanism into the cement-based materials. Regardless of many research studies on the effect of nano alumina on the mechanical performance of cement mortar, there has not been a widespread study examining the effect of nano Al2O3, curing period (t), and water-to-cement ratio (w/c) on the compressive strength (σc) of cement mortar. Consequently, this study explores the subject matter which could be helpful for the building and construction field. In this study, the data collected on the compressive strength of the cement mortar modified with different percentages of nano alumina ranging from 0.5% to 13.5% (by dry weight of the cement) were gathered from the literature. A nonlinear modeling NLM and statistical data analysis were performed on above 500 assembled data. The w/c ratio of the cement mortar varied from 0.3% to 0.79%, and the compressive strength of cement mortar modified with nano alumina and cured for 1,7 and 28 up to 90 days leads to high strength ranged from (10 MPa to 68 MPa). The result of NLM showed that curing period has the highest effect on the compressive strength in combination with water to cement ratio and percentage of nano alumina replacement with a coefficient of determination (R2) of 0.85.

Portland cement is considered the most involved product in environmental pollution. It is responsible for about 10% of global CO2 emissions [1]. Limestone dust is a by-product of limestone plants and it is produced in thousands of tons annually as waste material. To fulfill sustainability requirements, concrete production is recommended to reduce Portland cement usage with the use of alternative or waste materials. The production of sustainable high strength concrete by using nanomaterials is one of the aims of this study. Limestone dust in 12, 16, and 20% by weight of cement replaced cement in this study. The study was divided into two parts: the first was devoted to the investigation of the best percentage of replacement of waste lime. The second part of the study evaluated the performance of concrete when adding nanomaterials. Three percentages of cement replacement 0.5%, 1%, and 1.5% with nano-Al2O3 were used. The most efficient content of hydrated lime used in this study which achieves sustainability and maintains the quality of concrete was (16%). On the other hand, it was found that the best percentage of nano-Al2O3 as a partial replacement of cement is 1.5%. [ABSTRACT FROM AUTHOR]

• Adding 1 % nano Al 2 O 3 maintained mechanical properties by reducing water absorption. • Nano Al 2 O 3 enhances decomposition temperature by 8.35 % and acts as a thermal barrier. • 1 % nano Al 2 O 3 additive improves t g by 8.76 % in the hydrothermal aging environment. • Aging led to wear property deterioration, but nano Al 2 O 3 decreased this effect. Glass fiber composites are widely used in offshore structures for marine application due to their exceptional strength-to-weight ratio, corrosion resistance, and durability. As offshore structures are exposed to harsh environmental conditions, including saltwater, fluctuating temperatures, and hydrothermal influences, understanding the effects of aging on structural integrity on glass fiber composites becomes very important. In this study glass fiber-reinforced epoxy nanocomposites with 1 % and 2 % nano Al 2 O 3 reinforcement were produced using the vacuum-assisted resin transfer molding. These composites were subjected to a three-month aging process in artificial seawater at a temperature of 70 °C. Mechanical properties were assessed through Tensile and Flexural Tests, while thermal properties were analyzed via TGA, DTA, and DSC analysis. To examine the structural characteristics, Fourier Transform Infrared (FT-IR) spectrophotometry was utilized, and SEM analysis was conducted. Wear properties were evaluated through dry sliding wear tests. Water absorption properties were determined in a precisely controlled seawater bath. The findings reveal that the incorporation of 1 % nano Al 2 O 3 effectively diminishes the water absorption rate, thereby safeguarding the mechanical, thermal, and structural properties within a hydrothermal environment. [Display omitted] [ABSTRACT FROM AUTHOR]

Purpose: This research aimed to prepare tetragonal zirconia polycrystals powder by coprecipitation method and study effects of addition of different amounts of nano Al2O3 (1, 2 and 4) wt.% on its microstructure and mechanical properties of (5Y-TZP) composite. Design/methodology/approach: The powder was uniaxial pressed at a pressure of 150 MPa and held for 60 s, and sintered at the 1500°C, held for two hours and then cooling down at 5°C/min to room temperature. Microhardness and fracture toughness tests were utilized to evaluate the mechanical properties of yttria tetragonal zirconia polycrystal composite. The microstructure has been observed using field emission scanning electron microscopy(FESEM). Findings: The results showed an addition of nano Al2O3 has a great influence on hardness and microstructure, the increase in Vicker's microhardness of composite samples with the increase in the nano Al2O3 wt.% and microstructure were characterized with homogeneous zirconia distribution, grain growth destruction with the increasing percentage of nano Al2O3. The most important influence is the enhancing of the densification process as the porosity decreased. The highest hardness and maximum fracture toughness were recorded at 4 wt.% nano Al2O3. Research limitations/implications: Ceramic matrix composites are developed to overcome the brittleness of ZrO2 and the low toughness of alumina by formation, a large difference of elastic behavior between matrix and particles(dispersion phase)which disturbs the stress field as a dislocation comes near a particle. Practical implications: Zirconia has mechanical properties similar to those of stainless steel. Yttria-stabilized tetragonal Zirconia (Y-TZP) is growing used in dentistry due to its good mechanical properties such as hardness and fracture toughness. Thus, controlling of microstructure by adding nanoalumina plays an important role in enhancing these properties. Originality/value: Study the adding bitty percentage from nano alumina on microstructure and mechanical properties of (5Y-TZP) ceramic. [ABSTRACT FROM AUTHOR]

Abstract Nanoporous materials can significantly promote the formation process of gas hydrate by reducing the barrier of physical chemistry. In this work, the CO 2 /H 2 /H 2 O hydrates formation with tetra-n-butyl ammonium bromide (TBAB) and nano Al 2 O 3 or carbon nano tube (CNT) were studied and compared in term of kinetic curves. It was found that both TBAB-Al 2 O 3 and TBAB-CNT could promote the CO 2 /H 2 /H 2 O hydrate formation process. Furthermore, compared with TBAB-Al 2 O 3 , TBAB-CNT has the better promotion effect on the CO 2 /H 2 /H 2 O hydrate formation process. It is interesting that the CO 2 /H 2 /H 2 O hydrate formation process with TBAB-Al 2 O 3 represents reformation phenomenon. It possibly forms sI CO 2 /H 2 /H 2 O hydrate firstly and finally forms semiclathrate CO 2 /H 2 /H 2 O hydrate. [ABSTRACT FROM AUTHOR]

Graphical abstract A versatile new green route for the synthesis of 4-alkyl-5-methyl-1H-pyrazol-3-ols through the promoting effect of nano Al 2 O 3 @C g in aqueous media via the four-component reaction of β-ketoesters, hydrazine hydrate, different aldehydes, and acetophenone derivatives. Preparation of the new nanostructure (nano Al 2 O 3 @C g) via a simple straightforward procedure form graphite and nano alumina and its characterization by FT-IR, EDAX, TGA/ DTG, FESEM, and ICP-AES techniques. Examining the reusability and recovery of the nano promoter (Al 2 O 3 @C g) in the synthesis of 4-alkyl-5-methyl-1H-pyrazol-3-ols within 4 runs without loss of activity as pharmaceutically efficient substrates and/or products. Exploiting the Lewis acidic capacity of nano Al 2 O 3 through expanding its area by embedding it on a graphite surface that elevated the catalytic activity the obtained nano promoter Al 2 O 3 @C g. Abstract A benign, simple, and efficient synthesis of 4-alkyl-5-methyl-1H-pyrazol-3-ols has been described in refluxing water through the four-component reaction of β-ketoesters, hydrazine hydrate, different aldehydes, and acetophenone derivatives in the presence of nano Al 2 O 3 @C g , as a novel nanocatalyst. The new promoter has been prepared via a straightforward procedure and characterized by fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDAX), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), and inductively coupled plasma atomic emission spectroscopy (ICP-AES) techniques. Utilizing water as the reaction medium, uncomplicated operational procedure, mild reaction conditions, application of a cost-effective, nontoxic, heterogeneous, easily available nanoscale inorganic-based catalyst, wide-range of substrates usage, and recovery and reusability of nano Al 2 O 3 @C g catalyst within 4 runs without activity loss, are some highlighted features of the reported method. [ABSTRACT FROM AUTHOR]

In this study, the effects of micro-Al2O3 (MA) and nano-Al2O3 (NA) on the mechanical properties and durability performance of a mortar containing fly ash (FA) were investigated. In the first step, MA and NA were added to the mortar (as a cement replacement) at dosages of 0%, 5%, 10% and 15% by weight. The flowability of the mixture containing NA and MA showed a dosage-dependent behavior, and the addition of MA resulted in a higher flow spread compared with NA. The flow spread increased at 5% (for both NA and MA), and a further increase in the particle content to 10% and 15% decreased the flow spread value. Although the presence of MA and NA contributed to increasing the compressive strength as the particle content increased, the addition of NA resulted in a greater increase in compressive strength (40% increase when adding 15% of NA). The highest splitting tensile strength was obtained when 10% NA was used, and a further increase in the particle content decreased the splitting tensile strength. In the optimization step, the effect of a binder replacement with FA (10, 20 and 30%) in the presence of 10% NA as the optimum level of additive was investigated. Generally, the addition of FA decreased the compressive strength. The highest drop in compressive strength was noticed at early ages, and there was no significant difference in strength development from 14 days to 28 days. A decreasing trend in the splitting tensile strength was observed with the addition of FA content.

The current research work, examines efficacy of asphalt mixes prepared with varied proportions of nano SiO 2 and nano Al 2 O 3. The study assessed the performance of modified asphalt mixes through Marshall stability, flow, indirect tensile strength, resilient modulus, Dynamic modulus, Flow number, and 4-Point bending tests. Elevated nanomaterial dosages notably enhanced high and intermediate temperature performance, nearly tripling rutting resistance, and augmenting fatigue resistance by approximately 130%. Elevated tensile strength ratios confirmed improved moisture resilience. The statistical analysis showed that nanomaterials had a significant influence on properties of asphalt mixes. Overall, diverse test approaches underscored the potential of nanomaterials in enhancing asphalt mix properties, promising durable and long-lasting pavements. • Investigate the use of nano SiO 2 and nano Al 2 O 3 , as modifiers for asphalt mixes. • The asphalt mixes were prepared with varying proportions of the two nanomaterials. • Incorporating nanomaterials improved rutting and fatigue properties of the mixes. • Nanomodified mixes exhibited higher stiffness and improved moisture resistance. • Asphalt mixes consisting of 2% nano Al 2 O 3 , demonstrated the best performance. [ABSTRACT FROM AUTHOR]

Exposure to corona discharge damages the polymeric structure of alumina trihydrate (ATH) filled silicone rubber composite insulators. In this work, an attempt has been made to enhance the resistance against sustained long term corona exposure of ATH filled silicone rubber by fabricating its co-filled composites through addition of a small amount of nano Al2O3. Fabricated specimens comprise a pristine sample of silicone rubber (SR), one micro 40wt% ATH (MSR) composite and two co-filled 39wt% ATH+1wt% nano Al2O3 (MSR1%) and 38wt% ATH+2wt% nano Al2O3 (MSR2%) composites with total particle loading of 40wt%. They are subjected to AC corona exposure produced from a needle electrode tip for seven days. Performance evaluation is achieved through SEM (Scanning electron microscopy), FTIR (Fourier transform infrared spectroscopy), hydrophobicity, and surface roughness. Test results show severe material ruptures occurred in SR but damage in the form of pits and voids in MSR and MSR1% in the area directly below the needle tip. Interestingly, MSR2% exhibits subdued damage and a compact lump structure. The hydrophobicity recovery rate is significantly higher below the needle tip than in the vicinity, and in the SR as compared to the other composites. Also noted is higher increment in average and peak surface roughness below needle tip, and strong resistance to roughness increment by MSR2%. FTIR results show higher concentration of hydroxylation and aluminum nitrites in MSR and the absorbance intensities of principal functional groups show fewer deviations in MSR1% and MSR2% relative to their virgin states. Based on experimental results, it is concluded that corona resistance of micro ATH filled silicone rubber can be enhanced through addition of small amount of Al2O3 by fabrication of co-filled composites. [ABSTRACT FROM PUBLISHER]

Aluminium based metal matrix composites have drawn more attraction due to their improved properties in structural applications for the past two decades. The fatigue behaviour of composite materials needs to be studied for their structural applications. In this work, powder metallurgy based aluminium (AA2014) alloy reinforced with micro and nano-sized alumina particles were fabricated and consolidated with the hot extrusion process. The evaluation of mechanical properties in the extruded composite was carried out. This composite was subjected to low cycle fatigue test with a constant strain rate. Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) images were used to evaluate the fatigue behaviour of aluminium-nano composite samples. Enhanced mechanical properties were exhibited by the nano alumina reinforced aluminium composites, when compared to the micron sized alumina reinforced composites. The failure cycle is observed to be higher for the nano alumina reinforced composites when compared with micron sized alumina composites due to a lower order of induced plastic strain.

A part of different countries' budget in the world annually is spent on the restoration and reconstruction of pavements damages. Hence, by increasing the quality of hot mix asphalt, the pavement researchers are constantly trying to improve the quality of hot mix asphalt, greatly reduce the incidence rate of damages in the roads and delay the incidence time as much as possible. Many studies show that the quality of hot mix asphalt can be improved by using additives. Nano Al2O3 is studied as an additive in this research and also, in order to improve the hot mix asphalt strength against the damages, the type of stone mastic asphalt is examined. Stone materials gradation used in this study is the average gradation proposed by Asphalt Pavement Regulation of Iran Roads (Publication 234) for stone mastic asphalt with a maximum aggregate nominal size of 20 mm. The bitumen consumed is bitumen 60-70 in Tehran Pasargad Oil Processing Complex. In order to prevent the draindown phenomenon in stone mastic asphalt which occurred according to the space between aggregates, the cellulose fibers with the amount of 0.3% hot mix asphalt weight are used to produce the hot mix asphalt. The effect of Nano Al2O3 additive on dynamic performance of stone mastic asphalt is investigated through dynamic creep test, wheel track test and indirect tensile fatigue test. Results show that addition of different percentages of Nano Al2O3 is capable to improve the dynamic performance of stone mastic asphalt, significantly. [ABSTRACT FROM AUTHOR]

In this study the effect of nano Al2O3 amount on the wear behaviours of Cu-nano Al2O3 composites, produced by powder metallurgy method, was investigated. In the scope of the study five different amounts of nano Al2O3 (0.5%, 1.0%, 1.5%, 2.0%, 2.5%) were added into pure Cu powders and mechanically milled for 240 min. The mechanically milled Cu-Al2O3 powders were pre-shaped by cold press under 600 MPa load. Pre-shaped samples were sintered in atmosphere-controlled furnace at 1000 °C for 1 h. Microstructure examinations, hardness measurements, and wear tests were carried out. In this study the hardness values were found to have decreased with increasing Al2O3 amount. Wear test results were compatible with hardness results. The highest weight loss was measured with 2.5% Al2O3 content. [ABSTRACT FROM AUTHOR]

Nanotechnology is one of the most important research areas and is presented in the vast fields of knowledge such as road construction industry has been surrounded. This paper has focused on the potential benefits of nano particles for modification of asphalt mixtures. Nano Al2O3 due to its unique properties can improve the dynamic characteristics of hot mix asphalt. Fatigue life of asphaltic samples is determined with indirect tensile fatigue tests by using of UTM. The results show that fatigue life of modified asphalt mixtures in compare with conventional mix is significantly increased. Beside, based on experimental results and numerical analyses, a new model is presented for prediction the fatigue behavior of asphalt mixtures modified with nano Al2O3. This model can completely characterized the fatigue performance of modified asphalt under dynamic loading conditions and different temperatures. [ABSTRACT FROM AUTHOR]