Addition Of Various Percentages Research Articles

An Experimental Study of Human Hair in Concrete as Fiber Reinforcement

Since the ancient times, many researches and advancements were carried to enhance the physical and mechanical properties of concrete. Fiber reinforced concrete is one among those advancements which offers a convenient, practical and economical method for overcoming micro cracks and similar type of deficiencies. Since concrete is weak in tension hence some measures must be adopted to overcome this deficiency. Human hair is generally strong in tension; hence it can be used as a fiber reinforcement material. Human hair fiber is an alternative non degradable matter available in abundance and at cheap cost, it is also reducing environmental problems. Also, addition of human hair fibers enhances the alternative non-degradable matter available in abundance and at cheap cost. It also reduces environment problems. Also, addition of human hair fibers enhances the binding properties, micro cracking control, imparts ductility and also increases swelling resistance. The experimental finding in our studies would encourages future research in the direction for long term performance to extending this cost of effective type of fibers for use in structural applications. Experiments were conducted o concrete cubes, cylinder and beams of standard sizes with addition of various percentages of human hair fiber i.e., 0%, 0.5%, 1%, and 1.5% by weight of cement, fine & coarse aggregate and results were compared with those of plain cement cubes, three cylinders and three beams were tested for their respective mechanical properties at curing periods of 3,7, and 28 days, Optimum hair fiber content was obtained as 1.5% by weight of cement

Sustainable Open-Graded Friction Course asphalt mixes with steel slag aggregates

A permeable mixture called Open-Graded Friction Course (OGFC) is used to lessen the effects of climate change, especially during periods of heavy rain. It is made up of open gradation, mostly coarse aggregates, and fewer fines. The advantages of an OGFC mixture include the removal of surface water from the pavement, noise absorption, increased frictional resistance and more. Steel slag is a waste product left over from the Iron and Steel industry that can be utilized as aggregates in OGFC mixes. The primary goal of this work is to assess the usage of steel slag aggregates in place of conventional aggregates to produce the OGFC mix for getting improved mixture properties. Five percentage substitutions were employed to examine the design and quality of the OGFC mix, namely, 0% (control mix), 25, 50, 75, and 100% of steel slag aggregates in place of conventional aggregates. Tests for air voids, binder draindown, unaged and aged Cantabro abrasion loss, and Indirect Tensile Strength (ITS) test were conducted to evaluate the performance of OGFC mixes containing different percentages of steel slag. The test results show that the performance of the mix was improved by the addition of various percentages of steel slag. The results of the physical properties tests on steel aggregates were better than that of conventional aggregates. The mix with steel slag aggregates exhibits a slight improvement in the drainage property when compared to the conventional aggregate mix, according to the test results of the draindown test. When compared to the conventional mix, the mix with 100% replacement at 5.75% bitumen content produced better raveling resistance, and the mix with 50% steel slag replacement indicated improved resistance to moisture susceptibility with good Tensile Strength Ratio. The test results showed 100% replacement mix performed better in terms of abrasion loss, binder draindown, and air voids content, while a 50% replacement mix performed better in terms of moisture susceptibility along with other parameters. Overall, it can be concluded that using steel slag aggregates in the OGFC mix can be advantageous and increase sustainability with utilization of steel slag as an industrial marginal material in construction of pavements.

Human Hair Waste Addition on Performance of Plain Concrete

Many researchers were endeavoring to up-heave the physical and mechanical properties of concrete sporadically. New methods and experiments are being successfully applied for revamping in the era of waste recyclable technology with proper application of the waste material in concrete as fiber material. These present studies have been undertaken to study the variation of concrete properties adding human hair as fiber reinforcement in concrete. At present male human hair is contemplated as no degradable substance as well as polluted materials for environment that are obtainable in plethora at cheap cost. Human hair used as fiber reinforcement reduces environmental pollution along with concrete’s weakness in tension. In this study, naturally available male human hair was collected, cleaned and added to plain concrete. Performance of plain concrete was investigated with addition of various percentages of human hair in concrete. For this purpose several normal concrete tubes as well as several number of concrete tubes with addition of 0%, 1%, 1.5% and 2% human hair as fiber reinforcement were experimented. It can be observed that compressive strength & split tensile strength of concrete was found maximum while addition of 2% & 1.5% male human hair respectively used in concrete considering as fiber material.

Effects of dry particle coating with nano- and microparticles on early compressive strength of portland cement pastes

It is known that nano-and microparticles have been very popular in recent years since their advantages. However, due to the very small size of such materials, they have very high tendency to agglomeration particularly for nanoparticles. Therefore, it is critical that they are properly distributed in the system to which they are added. This paper investigated the effects of dry particle coating with nano-and microparticles to solve the agglomeration problem. For a clear evaluation, paste samples were preferred to detemine the compressive strength. Nano-SiO2 and nano-CaCO3, micro-CaCO3 and micro-SiO2, also known as silica fume, were selected as particulate additives. It was studied by the addition of various percentages (0.3, 0.7, 1, 2, 3 and 5%) of nano-and microparticles in cementitious systems, replacing cement by weight with and without dry particle coating. Dry particle coating was made by using a high-speed paddle mixer. Portland cement and additive particles were mixed at 1500 rpm for 30 seconds in high-speed powder mixer designed for this purpose. The 3-day compressive strength of the cement-based samples to which particles were added at the specified rates was determined and the effect of the dry particle coating on the early strength was investigated. According to the results, it was observed that the production of paste with the dry particle coating technique gave higher compressive strength compared to the production of paste directly in early period. Especially with dry particle coating, compressive strength increased more than 100% in paste samples containing 0.3% nano-SiO2 compared to direct addition without coating.

Effect of reduced graphene oxide nanoparticles as anticorrosion material on mild steel substrate

Reduced graphene oxide(rGO) has a lot of potential in the area of corrosion control of metals, because of its excellent barrier properties, dispersion capabilities, and impermeability. The current work hires on the corrosion resistance action of reduced graphene oxide(rGO) as an inhibitor for mild steel in simulated concrete pore solution. Here, three different nano rGO contained epoxy coatings were prepared by varying the percentage of rGO. The anticorrosion behaviour of rGO integrated epoxy composite coating was evaluated using open circuit potential and polarization studies. The results indicated that rGO nanoparticles were properly distributed in the epoxy coating and showed excellent barrier properties. Moreover, anti-corrosion processes for composite coatings improved by the addition of various percentages of rGO were apparently hypothesized, implying that epoxy coating containing 1.0 wt.% rGO showed better corrosion resistant behaviour in concrete pore solution medium containing 0.5M NaCl solution.

Influence of nano-silica on early age and durability properties of cement mortars

This paper investigates the performance of cement mortar with the addition of various percentages of nano-silica (3%, 5% and 10%) at constant water-to-cement ratio. Early age properties of mortar along with the hydration mechanism were determined using flow test, setting time test, micro calorimetry and thermo-gravimetric analysis tests. In addition, hardened and durability-related properties using migration resistance and thermal conductivity tests were evaluated. It was observed that the workability and the setting time decreased largely according to the increase in the percentage of nano-silica as compared to the reference mortar. This finding is confirmed by micro calorimetry results, which indicate a significant increase for the heat evaluation in the presence of nano additives. The thermo-gravimetric analysis indicated the acceleration of the hydration reaction and continuation of the prolonged pozzolanic reaction, which results in the densification of the microstructure confirmed by the increase of compressive strength by 21% at 112 days for 10% addition of nano-silica as compared to the reference mortar. Moreover, the incorporation of nano-silica had also improved the durability of the mortars by reducing the effective diffusion coefficient and thermal conductivity by 46% and 40%, respectively, especially for mortar containing 10% nano-silica.

Fate of Nano Soil Particles and Their Influence on Geotechnical and Physiochemical Properties of Sandy Soil

Laboratory study was conducted to estimate the effectiveness of geotechnical and physio-chemical properties of sandy soil stabilized mixed with nano-fine sandy soil particles. The specimens’ soils were brought together at Ismailia province. Then, through high energy milling process -soil specimens as Nano size were derived powdering process of specimens. Due to the incomplete quantity produced from the powdering process, various percentages (1%, 12%, 3% and 4%) as Nano specimens were added to experiment. The different rates of specimens as Nano size added in sandy soil have suitable moistness at supreme soil density (dry soil). The result shows that the addition of various percentages of Nano-soil particles to sandy land enhanced property of shear strength; particles strength and compressive strong suit of become stable sandy soil. Also data illustrated that the Atterberg limits of sandy soil stabilized using nano-soil were augmented compared to the control treatment. The augmentation of the electrical conductivity of the sandy soil using nano fine soil as filler allows the potential for use it as soil conditioner technologies. Sandy soil treated by nano fine soil cause a valuable augmentation in the electrical characteristics, tensile strength and thermal stability of sandy soil. In addition, soil hydro physical properties of sandy soil were improved by nano fine sandy soil application. In conclusion, applied various percentages of Nano-specimens gave a vital starring role to improve and boosted the geotechnical, hydro physical and dielectric and electrical investigation properties of sandy soils. The result shows that the addition of 1, 2, 3 and 4% nano-soil particles to sandy soil enhanced the property of shear strength, soil strength and compressive strength of stabilized sandy soil. Also the data showed that the Atterberg limits of sandy soil stabilized using nano-soil were augmented compared to the control treatment. The augmentation of the electrical conductivity of the sandy soil using nano fine soil as filler allows the potential for use it as soil conditioner technologies. Sandy soil treated by nano fine soil cause a valuable augmentation in the electrical characteristics, tensile strength and thermal stability of sandy soil. In addition, soil hydro physical properties of sandy soil were improved by nano fine sandy soil application. In conclusion, applied small amount of nano-soil has a major role to recover and enhanced the geotechnical, hydro physical and dielectric and electrical investigation properties of sandy soils.

Comparison of Mechanical Properties of Normal and Fibre Reinforced Concrete (Grade M15)

Concrete is weak in tension, hence some measures must be adopted to overcome this deficiency as well as to enhance physical and other mechanical properties but in more convenient and economical method. Through many research from the past, it has been observed that addition of different types of fibres has been more effective for this purpose. This report presents the work undertaken to study the effect of steel and hay fibre on normal cement concrete of M-15 Grade on the basis of its mechanical properties which include compressive and tensile strength test and slump test as well. Although hay fibres are abundantly available in Nepal, no research have been popularly conducted here regarding the use of hay fibres in concrete and the changes brought by it on concrete’s mechanical properties. Experiments were conducted on concrete cubes and cylinders of standard sizes with addition of various percentages of steel and hay fibres i.e. 0.5%, 1% and 1.5% by weight of cement and results were compared with those of normal cement concrete of M-15 Grade. For each percentage of steel and hay fibre added in concrete, six cubes and six cylinders were tested for their respective mechanical properties at curing periods of 14 and 28 days. The results obtained show us that the optimum content of fibre to be added to M-15 grade of concrete is 0.5% steel fibre for compression and 0.5% hay fibre content for tension by weight of cement. Also, addition of steel and hay fibres enhanced the binding properties, micro cracking control and imparted ductility.
 In addition to this, two residential buildings were modeled in SAP software, one with normal concrete and other with concrete containing 0.5% steel fibre. Difference in reinforcement requirements in each building was computed from SAP analysis and it was found that 489.736 Kg of reinforcement could be substituted by 158.036 kg of steel fibres and decrease in materials cost of building with 0.5% steel fibre reinforced concrete was found to be Rs. 32,100.

Aqueous phase reforming of sorbitol over Ca doped Ni/Al2O3 for value-added chemicals production

Biomass is currently one of the preferred sustainable and renewable source of energy, with countless potential as a basis for hydrogen and value added chemical production. Various researches has been done to optimize the usage of biomass as the source of energy, one of them is conversion of polyols such as sorbitol to hydrogen and value-added chemicals using the low energy, low temperature, high yield process of aqueous phase reforming, in the presence of suitable and compatible catalyst. In this research, Ni/Al2O3 doped with varying percentage of Ca (0.5%, 3% and 5%) are synthesized via wet impregnation method and the resulting catalysts are subjected to various characterization techniques such as TGA, FESEM-EDX, H2-TPR, BET and XRD to assess the physicochemical properties. The catalytic activity test was carried out in a batch reactor (230˚C, 20 bar and 1 hour) and the resulted liquid products were analyzed using HPLC analysis to determine the products formed. Based on the findings, addition of Ca has shown prodigious effect on physiochemical properties of the Ni/Al2O3, where addition of Ca resulted in lower reduction temperature, good surface morphology and element dispersion, good surface area and pore size, and good interaction between the metals and support as compared to the pristine Ni/Al2O3. Congruently, the addition of various percentages of Ca produces various types of valuable chemicals such as ethanol, 1-propanol, propanal and ethylene glycol at relatively high selectivity percentage, with relatively good sorbitol conversion ranging from 69.09-75.29%.

Compaction and swelling behavior of black cotton soil mixed with different non-cementitious materials

A series of compaction tests and one-dimensional swell tests were conducted to study the effect of addition of various percentages of rice husk ash, fly ash, and stone dust on compaction and swelling behaviour of black cotton soil. Specimens were prepared by adding 4, 8, 12, 16 and 20% by weight of various industrial waste materials to the black cotton soil. Standard proctor test was adopted to study the compaction behaviour of mix. For swelling behaviour one-dimensional swell test was performed by fixed ring consolidometer. Test results have shown that the optimum moisture content (OMC) increases due to addition of rice husk ash while maximum dry density (MDD) decreases. However, slight decrease due to the addition of fly ash and no significant change due to the addition of stoned dust in MDD have been observed. Decrease in the OMC was observed due to the addition of fly ash and stone dust. Swell potential and swell pressure of the soil decrease with the increase in percentage of additives. It is found from the swelling tests that all stabilizers can effectively suppress the heave and swelling pressure, but rice husk ash is more effective in suppressing the swelling behaviour.

The Effect of Carbon Nanotube Loading on Wettability of Solder Paste SAC 237 and Different Substrates

Wettability of Pb-free soldered surface is one of the main solderability classifications. The aim of this study is to investigate the effect of various percentages of carbon nanotube (CNT) loading (0 – 4%) on the wettability of solder paste SAC 237 and different substrates namely copper (Cu) and tin (Sn). The influence of surface roughness on the wetting behaviour was also studied. Both substrates were undergone a mechanical abrasion process by using four different grit sizes (P240 , P400, P600 and P800) before performing the reflow soldering process using a reflow oven at a temperature of 180°C for 13 minutes. The surface roughness of the substrates was characterized by using a profilometer. Meanwhile, wettability tests were performed by using the optical microscope. Both substrates have shown similar behaviour; the rougher surface gives better wettability compared to the smoother one. The wettability of SAC 237 is not significantly affected by the addition of various percentages of CNT. However, CNT loading in the solder paste has shown the different wetting behaviour for both substrates.

Reduction of Expansive Index, Swelling and Compression Behavior of Kaolinite and Bentonite Clay with Sand and Class C Fly Ash

Swelling behavior of expansive soil has always created problems in the field of geotechnical engineering. Generally, the method used to assess the swelling potential of expansive soil from its plasticity index, shrinkage limit and colloidal content. Alternative way to evaluate swelling behavior is from its expansive index (EI) and swelling pressure value. The present study investigates the reduction of EI and swelling pressure for kaolinite and bentonite clay when mixed with various percentages of Ottawa sand and Class C fly ash. The percentages of Ottawa sand and Class C fly ash used were 0–50 % by weight. The results show that there is a significant reduction in the swelling properties of expansive soil with the addition of Ottawa sand and Class C fly ash. The reduction in EI ranged approximately from 10 to 50 and 4 to 49 % for kaolinite and bentonite clay, respectively. Also the maximum swelling pressure of kaolinite and bentonite clay decreased approximately 93 and 64 %, respectively with the addition of various percentages of Ottawa sand and Class C fly ash. Standard index properties test viz., liquid limit, plastic limit and linear shrinkage test were conducted to see the characteristics of expansive soil when mixed with less expansive sand and fly ash. Also, for these expansive soils one dimensional consolidation test have been conducted with sand and fly ash mixtures and the results were compared with pure kaolinite and bentonite clay.

Road-surface properties affecting rates of energy dissipation from vehicles

The rates of energy that moving vehicles dissipate to road surfaces as well as noise emissions and their propensities for pitting (and hence their repair costs per year) all depend upon the structural properties of these surfaces. Thus, to increase the strength of bituminous concrete (i.e. a typical flexible road-surface) has been one of the major recent aims in highway engineering. The present study explored techniques that will increase these strength properties by modifying the material, using rubber latex, through rubberization and hence, improve the strength of the flexible trafficked surface when in contact with vehicles. At the optimal design asphalt (i.e. bitumen) content of 4.68%, the successive addition of various percentages of the rubber latex produced a design value of 1.65% rubber content, which increased the stability of the roadway from 1595 to 2639 N (i.e. an 65.5% increase) and the density from 2447 to 2520.8 kg/m 3 (i.e. a 3.02% increase). This shows that the addition of rubber latex to bituminous concrete (a flexible road-surface) increased sustainability and the strength (in terms of stability and density). Similarly, the air voids and voids in the mineral aggregate (VMA) were reduced by introducing latex from 4.22% to 3.45% (i.e. a 17.06% reduction) and 16.25% to 13.43% (i.e. an 17.4% reduction), respectively. Whereas, the reduction in voidage volume added strength to the bituminous concrete by increasing its stability and density, the reduction in VMA had no positive impact on the strength properties of the flexible road-surface.

Effects of Osmotic Pressure on the Crosslinking Reaction of Tapioca Starch

AbstractTapioca starch was crosslinked with 0.1 % sodium trimetaphosphate (STMP) in the presence of alkali and of osmotic pressure enhancing salts such as sodium sulfate and sodium chloride. The addition of various percentages of sodium sulfate to the crosslinking reaction mixture changed the pasting properties of the product starch as measured in the RVA (Rapid Visco Analyser). Peak viscosity (PV) and final viscosity (FV) are first increased with the increase in osmotic pressure followed by a decrease of the viscosities after further pressure increase. Breakdown (BD) is decreased in line with the increase of the osmotic pressure with very good correlation (R2 = 0.96). These pasting characteristics are attributed to the inhibited swelling without disruption of the starch granules due to the crosslinking reaction. If sodium chloride is used as an osmotic pressure enhancer of the crosslinking reaction, both pasting properties (PV, FV) decrease linearly with the increase in osmotic pressure with very good correlation (R2 = 0.98 and 0.99, respectively). The BD is dramatically decreased to zero (no breakdown) after applying the osmotic pressure and remains zero after further increase in osmotic pressure. These properties are also attributed to the pasting characteristics of the crosslinked starch. The increase in pasting temperature (PT) with increasing osmotic pressure for both sodium sulfate and sodium chloride demonstrates the increase of the gelatinization temperature of the starch granules. The enhancement of the osmotic pressure can promote the activity of the crosslinking agent.

Sintered glass ceramic composites from vitrified municipal solid waste bottom ashes

A glass ceramic composite was obtained by sinter-crystallisation of vitrified municipal solid waste bottom ashes with the addition of various percentages of alumina waste. The sintering was investigated by differential dilatometry and the crystallisation of the glass particles by differential thermal analysis. The crystalline phases produced by the thermal treatment were identified by X-ray diffraction analysis. The sintering process was found to be affected by the alumina addition and inhibited by the beginning of the crystal-phase precipitation. Scanning electron microscopy was performed on the fractured sintered samples to observe the effect of the sintering. Young's modulus and the mechanical strength of the sintered glass ceramic and composites were determined at different heating rates. The application of high heating rate and the addition of alumina powder improved the mechanical properties. Compared to the sintered glass ceramic without additives, the bending strength and the Young's modulus obtained at 20°C/min, increased by about 20% and 30%, respectively.

Nano-sized Si 3N 4 reinforced NiFe nanocomposites by electroplating

Permalloy NiFe/Si 3N 4 nanocomposite layers were electroplated on a copper substrate. The volume fraction of nano-sized Si 3N 4 particles in NiFe matrix was controlled by the addition of various percentages of Si 3N 4 particles in the NiFe electrolyte. The nanocomposite layers of up to 400 μm were analyzed by a scanning electron microscopy (SEM). Microhardness test was performed. With nano-sized Si 3N 4 particles in the NiFe matrix, the microhardness of NiFe was improved. The samples were then annealed at 800 °C for about 20 h. The microhardness declined more with more Si 3N 4 particles in the NiFe matrix. The analysis result from energy dispersive spectrometer (EDS) in the SEM showed that the hardness declination could be caused by the segregation of Si 3N 4 in the NiFe matrix. Finally, this paper presents nanocomposite micromolds fabricated by electroplating onto polymer molds that were fabricated by micro-stereolithgraphy.

Fabrication of stable superconductive wires with YBa2Cu3Ox/Ag2O composite core

The problem of maintaining the oxygen stoichiometry of the Y1Ba2Cu3Ox (the so-called 123) compound at the desired level of x=6.0±0.1 when fabricating superconducting wires using the powder-in-tube method is addressed. A solution to this problem appears to be incorporating an unstable oxide like Ag2O in the core material, such that it acts as an in situ oxygen donor during the final sintering or annealing stage. Moreover, the segregation of Ag at the grain boundaries of the 123 grains and at the porosities seems to be a possible reason for the considerable improvement of the critical current density Jc of these wires. The effect of processing parameters, like different sintering temperatures and addition of various percentages of either Ag or Ag2O, is presented. Finally, in order to test conservation of superconductive properties during handling, the wires were subjected to different degrees of bending, and the subsequent effect on superconducting transition temperature, Tc and Jc, is reported.

Formulation of silver loaded manganite based thermistor paste and application of percolation theory for sudden transition in conductance

A low cost thermistor paste using manganite (Mn1.5CoN0.5O4) as functional material, prepared by sintering manganese, cobalt, and nickel oxides, is formulated for use as planar temperature sensors. The paste contains glass frit as binder and silver metal (0% to 60% by weight) as conducting phase instead of RuO32. Thermistors are fabricated by screen printing of these pastes on alumina substrates and effect of addition of various percentages of silver on electrical properties like sheet resistivity and temperature coefficient of resistance (TCR) are measured in the temperature range of 25–200 °C. Up to 50% addition of silver the pastes show a negative TCR with thermistor constant in the range 3000–5000 K, and sheet resistivity of the order of 106 Ω/⧠, whereas the pastes with 55% and 60% silver show a drastic reduction in the value of sheet resistivity (20 Ω/⧠) and have positive TCR with thermistor constant of the order of 200–300 K. NTC thermistors have high sensitivity of 5%–7%/K and PTC thermistors have sensitivity of 1%–2%/K. This interesting result of NTC-PTC transformation in relation to silver concentration, along with the sudden change in the conductivity (of about 6 orders of magnitude) at a critical concentration of silver, is discussed in the paper. This has been explained on the basis of an effective medium theory (Springett model) and formation of some metallic silver complex.

Effect of Carbon Dioxide on Toxicity of Hydrocyanic Acid and Methyl Bromide to Adults of the Confused Flour Beetle and Granary Weevil at Two Different Temperatures

Experiments were conducted with adult confused flour beetles, Tribolium confusum Jacquelin duVal, and granary weevils, Sitophilus granarius (L.), to determine the effect of CO2 on the efficacy of hydrogen cyanide (HCN) or methyl bromide fumigation. The effectiveness of HCN fumigation to T. confusum adults was increased up to 4 times by addition of various percentages of CO2; while that of methyl bromide fumigation was increased up to 1.5 times. Effectiveness of HCN fumigation to S. granaries adults was increased up to 1.7 times by the addition of various percentages of CO2; that of methyl bromide fumigation was increased up to 1.4 times. The greatest susceptibility was shown by confused flour beetle adults to HCN + CO2 mixtures at 80°F.