Addition Of Different Types Research Articles

Wool and coir fiber reinforced gypsum ceiling tiles with enhanced stability and acoustic and thermal resistance

An attempt has been made to enhance the properties and applications of gypsum ceiling tiles by utilizing the excellent thermal insulation and flame resistance properties of wool and the durability and strength of coir. Gypsum based ceiling tiles are ubiquitously used for false ceiling applications but have several limitations. Different types of additives, finishes and chemicals have been used to overcome the lack of structural integrity under large impacts, poor resistance to moisture and limited acoustic resistance of gypsum ceiling tiles. Few studies have shown that reinforcing gypsum with natural materials provides better performance properties. Wool and coir are biodegradable natural fibers that are available in large quantities at low costs and have some unique properties suitable for developing green building materials. In this study a blend of wool and coir were used to enhance properties and performance of gypsum ceiling tiles. Composites were manufactured by using 30% fiber and 70% gypsum and varying the proportion of wool and coir between 25–75%. The reinforcing fibers were combined with gypsum using water and no other chemical or additives are necessary, making the production of tiles simple and environmentally friendly. Fiber reinforced gypsum showed higher strength (up to 90% higher) and modulus (up to 7%) and also better resistance to moisture. Wool fibers provided substantially higher moisture resistance while coir provided better strength. A blend of the two fibers provided a flame resistance rating of V1 compared to V0 for pure gypsum. Reinforcing gypsum with coir and wool would not only improve thermal and acoustic properties but will also help to reduce cost and make a major portion of the gypsum ceiling tiles biodegradable and thereby decrease environmental burden and helps towards promoting green building initiatives.

Electromagnetic shielding properties of cementitious composites containing carbon nanofibers, zinc oxide, and activated carbon powder

Exposure to electromagnetic radiation is known to cause many adverse effects such as malfunction of electronic devices and health problems in humans. Since currently used metallic shields suffer from various drawbacks, using construction materials that would provide the same amount of shielding has become a novel research area in the construction industry. Set of experiments were carried out to find the effect of carbon nanofibers, zinc oxide, and activated carbon powder on electromagnetic interference shielding in cementitious composites. Additionally, the impact of these additives on mechanical and electrical conductivity was measured. For these experiments, four different types of carbon nanofibers were used to establish the best type of carbon nanofibers. Different contents of each additive were mixed into the cementitious composite to find the optimal content of each additive. These three different types of additives were then combined with 12 mm unsized carbon fibre within the cementitious matrix. Effects of the hybrid composites were measured similar to previous tests to find out the best combination of additives that would provide the optimum amount of electromagnetic shielding. Electromagnetic shielding tests were carried out within the frequency range of 30 MHz to 1.5 GHz according to ASTM D4935 – 18 standard method. Results showed that the inclusion of individual additives did not have a significant impact on the electromagnetic shielding properties. The best shielding properties were obtained when 0.5% of activated carbon powder was combined with the carbon fibre, which was 42.5–60.0 dB.

Influence of additives on the structural performance of cement-stabilised rammed earth

The influence of additives on the structural behaviour of cement-stabilised rammed earth was investigated through an experimental programme based on 13 different mixes with varying cement contents (6, 8 and 10% by earth weight) and three different types of additives (superplasticiser, air-entraining agent (AEA) and hardening accelerator). In total, 156 specimens were fabricated and tested at 7 and 28 days in order to compare their compressive strength and other properties such as stress–strain relationships, shrinkage and workability. The results highlighted the essential role of cement in increasing the compressive strength of the material. Specifically, cement contents of 6%, 8% and 10% corresponded, respectively, to strength increases of 41%, 80% and 92% compared with the reference mix with a mean compressive strength of 1.15 MPa. The AEA was found to be the most effective additive for increasing the compressive strength, with obtained strengths of up to 2.93 MPa (an increase of 155% compared with the reference mix). The efficiency of each mix was evaluated through a strength/cost ratio. In addition, an overall comparison of compressive strength, shrinkage, deformation, cost and workability was performed using an analytic hierarchy process. Finally, the experimental results were compared with the mechanical requirements of various codes.

Multi-Criteria Selection of Additives in Porous Asphalt Mixtures Using Mechanical, Hydraulic, Economic, and Environmental Indicators

Porous asphalt (PA) mixtures are more environmentally friendly but have lower durability than dense-graded mixtures. Additives can be incorporated into PA mixtures to enhance their mechanical strength; however, they may compromise the hydraulic characteristics, increase the total cost of pavement, and negatively affect the environment. In this paper, PA mixtures were produced with 5 different types of additives including 4 fibers and 1 filler. Their performances were compared with the reference mixtures containing virgin bitumen and polymer-modified bitumen. The performance of all mixes was assessed using: mechanical, hydraulic, economic, and environmental indicators. Then, the Delphi method was applied to compute the relative weights for the parameters in multi-criteria decision-making methods. Evaluation based on distance from average solution (EDAS), technique for order of the preference by similarity to ideal solution (TOPSIS), and weighted aggregated sum product assessment (WASPAS) were employed to rank the additives. According to the results obtained, aramid pulp displayed comparable and, for some parameters such as abrasion resistance, even better performance than polymer-modified bitumen, whereas cellulose fiber demonstrated the best performance regarding sustainability, due to economic and environmental benefits.

Effects of boron on the mechanical properties of polymethylmethacrylate denture base material.

The objective of this study was to determine whether the addition of different types of boron (Borax, Boric Acid and Colemanite) to polymethyl methacrylate denture base resin would improve flexural and impact strengths, and surface hardness of polymethyl methacrylate. Borax, Boric acid, Colemanite were added to heat polymerized polymethyl methacrylate specimens were prepared for flexural strength (65x10x2.5 mm), impact strength (50x6x4 mm), and hardness (20x6x4 mm) tests according to the manufacturers' instructions (n=10). To determine flexural strength of the specimens, they were loaded until failure on a universal testing machine using a three point bending test. Specimens were subjected to the Charpy impact test machine. Hardness of the specimens was measured with an analog shoremeter Shore D. The data were analyzed with Kruskal-Wallis and Mann-Whitney U tests (α=0.05). The highest mean flexural strength value was seen in 3% Borax group and followed by 1% Colemanite group. In addition, the highest mean impact strength value was recorded in 1% Colemanite group, and differences between 1% Colemanite group and control group were found to be statistically significant (p=0,001). Furthermore, there was significant difference in hardness between control group and all other groups (p<0.001). The addition of 1% Colemanite to polymethyl methacrylate improved the mechanical properties of PMMA.

Investigating the Performance of Hot Mix Asphalt Modified with Chemical Additives.(Dept.C)

The Egyptian roads suffer from many distresses, which depends to a significant extent on the mechanical properties of the asphaltic layer. Therefore, scientists and engineers are constantly trying to improve the mechanical properties of the asphaltic mixtures. One common method of improving the performance of asphaltic mixtures is the use of different types of additives. The objective of this research is to study the effect of using chemical additives on the mechanical properties of hot mix asphalt (HMA). Three chemical additives were used. The additives were Addicrete PVS, Adibond 65 and Silica gel, that were added with different ratios of 5, 10, 15 and 20 % by the weight of optimum asphalt content in addition to the original mix. Marshall test, Indirect tensile strength test and Moisture susceptibility test were conducted on the investigated mixes. Testing results on the modified mixes were compared with the original mix. The results show that exploitation of Addicrete PVS and Silica gel at 10% content enhanced the worth of Marshall stability, Marshall stiffness, indirect tensile strength, TSR and improved the value of flow whereas decreased the value of bulk density compared to the control mix. Also, the results showed that the most effective content at that adding of Adibond 65 yielded the most effective results was 15%.

Behavioural interface-bonding and chemical characterization of silane and wax based additives on latex modified asphalt binders

This research aims to evaluate the behavioural interface-bonding response of modified asphalt binders towards different types of additives. In this study, 6% natural rubber latex (NRL) was added into a conventional asphalt binder (PEN 60/70) with the subsequent addition of 0.1% silane additive and 0.3% Gripper (wax based) additive, based on the weight of the asphalt binder. The chemical functional groups and the effects of oxidation on the specimens were determined from attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The contact angle and surface free energy of the asphalt binders were measured using a goniometer device and analysed using the DROP image Advanced Software. Results from this study showed that the rubberised asphalt binders, with or without additive incorporation, possessed improved resistance to oxidation due to increases in CH and OH functional group concentrations, as well as improved wettability rate. In addition, the NRL modified asphalt binder with additive incorporation exhibited outstanding performance compared with PEN 60/70 and NRL modified asphalt binder without additive. Both additive incorporations showcased comparable performances, but with the Gripper additive incorporation having a better performance at different ageing conditions. Overall, the additive addition as surfactant showcased the potentiality to improve the interfacial bonding behaviour of NRL modified asphalt binders with aggregate, hence improving resistance to permanent deformation and fatigue cracking.

Improving the mechanical properties of lightweight foamed concrete using various types of fibres

Lightweight foamed concrete has recently been adopted as a more sustainable construction material due to various features such as reduction in member size, better thermal insulation, and cost savings. This work examines an attempt to improve the brittle nature of foam concrete with the addition of different types of fibres. Five types of fibres were used: steel fibres (hooked-ends), micro steel fibres (straight ends), carbon, glass, and polypropylene fibres. The effect of fibre type on the fresh (density and flowability) and hardened (compressive strength, splitting tensile strength, flexural strength, and static modulus of elasticity) properties of lightweight foamed concrete were thus investigated. The results collected from the experimental work revealed that steel fibres significantly improve the performance of lightweight foamed concrete in terms most properties while other types of fibres (carbon, glass and polypropylene fibres) improved properties at different levels to the steel fibres. Using 0.45 hooked-ends steel fibres gave the most significant improvement in splitting, flexural strength, modulus of elasticity and compressive strength at 162.5%, 83.78%, 72.41%, and 63.63%, respectively.

Effect of starch and dairy proteins on the gluten free bread formulation based on quinoa

Quinoa flour was used as base for designing new gluten free bread formulation. The proximate composition, physical, functional and thermo-mechanical properties of quinoa flour were first investigated, and the effect of addition of different types of starch (native and modified starch from corn and potato), and of different dairy proteins (whey proteins and sodium caseinate) on the properties of quinoa flour and on bread quality were further studied. The addition of potato starch to quinoa flour caused higher increase of starch gelatinization and breakdown compared to corn starch. Moreover, when corn starch was incorporated a delay in the pasting process was registered. The dairy proteins influenced in different manner the thermo-mechanical properties of dough; whey proteins decreased dough resistance to mechanical constrains, while sodium caseinate increased it. The bread-making test indicated that the addition of corn or potato starch to the quinoa flour allows slight improvement of the specific volume of the breads. Further improvement of the bread specific volume and crumb firmness was observed when combining sodium caseinate with corn starch. In case of the bread samples with modified starch from corn, the incorporation of either whey proteins or sodium caseinate resulted in improved specific volume and crumb firmness.

Study on the Friction and Wear Properties of Magnetorheological Fluids Based on Different Lubricant Formulas

Based on the preparation of magnetorheological fluids, material selection, proportioning method, and stability principle, this paper has conducted in-depth research on its friction and wear property. Firstly, the wear mechanism of magnetorheological fluids is analyzed theoretically. Secondly, an orthogonal test of magnetorheological fluid configuration with 6 lubricating additives of different types(oleic acid, hydrogenated castor oil, Teflon, boron nitride, molybdenum disulfide, graphite) and different mass fractions(0.5%, 1%, 1.5%, 2%) was done and the friction and wear property of magnetorheological fluids under different lubricants were compared. Finally, by analyzing and evaluating the experimental data, the general rule of lubricity additives used in the formulation of magnetorheological fluids with excellent performance was summarized, and the formulation of magnetorheological fluids with superior performance was obtained.

Evaluation of Addition of Carbon Nano Materials Over Properties of an Elastomeric Matrix

In the present work, the effect of the addition of different types of carbon nano structures on the mechanical, thermomechanical and thermal properties of a radial structure of styrene-butadiene-styrene (SBSR) copolymer matrix is reported. Different carbon nanostructures were used as nano-rein-forcements: expanded graphite (XG), graphene oxide (GO), reduced graphene oxide (RGO) and exfo-liated graphene (EG). These carbon structures present various functional groups, such as carbonyl, epoxy, and others, which are the responsible for the interaction between the polymer matrix and the nano particles. The compatibility induced between the nanomaterials and the elastomeric matrix fa-vors the stable dispersion of the nanocomposites during their obtention process. For instance, the ad-dition of GO increased in 10 and 16% the tensile strength and storage modulus of the nanocomposites. The fracture surface patterns in the nanocomposites after the tensile test was observed by scanning electron microscopy. Also, the dynamic mechanical analysis (DMA) and thermal characterization showed differences in the viscoelastic behavior of the reinforced nanocomposites with different carbon nanomaterials.

Mechanical characteristics research of new asphalt pavement structure based on geogrid

In order to study the mechanical characteristics of new asphalt pavement structural materials, UTM testing machine and Overlay Test (OT) testing machine, four-point fatigue test, tensile test and bending strength test have been carried out on different types of grid asphalt mixtures. The result shows: the addition of different types of grids can effectively improve the mechanical properties of the asphalt concrete pavement structure; geogrid addition can improve the stress on the road surface, improve the strength of pavement materials, it can effectively alleviate early generation of fatigue cracks on the road surface; it can also effectively avoid the problem of rutting damage on the whole road surface after partial damage to the road surface; can effectively promote pavement stress dispersion, improve pavement structure stability, make the pavement structure more stable, improve its service life.

Outcomes of advanced biodiesel with nanoparticle additives on performance of CI engines

Abstract Biodiesel is a potential alternative fuel source that shows the importance of fossil fuels and helps to keep diesel engines in use for a long time. Numerous research works have shown that biodiesel suffers from its drawbacks, including high viscosity, low volatility, low heat value and high NOx emissions, although some features of biodiesel promote their use, such as CO2, HC, and PM reduce emissions. Some researchers have also noted that these impairments can be overcome with the help of additives and increasing the use of biodiesel. The reduction in harmful effects of emissions on the environment has attracted the attention of researchers towards biodiesel additives. In this work the conclusion of experimental works from different types of additives mixed with jatropha biodiesel is presented. Experimental work includes various nanoparticles such as aluminum (Al), copper (C), zinc oxide (ZnO), carbon nano tubes (CNT), graphene oxide (GO), graphene nanoplates (GNP), carbon nanotubes (CNTs) and multiwalled carbon nanotubes (MWCNTs) etc. In addition to jatropha biodiesel and blends, nano additives reduced the ignition delay period. The combustion process began early, and brake specific fuel consumption decreased as well as an increase in brake thermal efficiency. The effects of various types of biodiesel additives on controlled and uncontrolled emissions of combustion ignition engines have been noted. Their qualities and demerits are also discussed.

Use of Polyphosphates and Soluble Pyrophosphatase Activity in the Seaweed Ulva pseudorotundata

The hydrolytic activity of different types of polyphosphates, and the induction of soluble pyrophosphatase (sPPase; EC 3.6.1.1) activity have been assessed in cell extracts of nutrient limited green seaweed Ulva pseudorotundata Cormaci, Furnari &amp; Alongi subjected to different phosphorus regimes. Following a long period of nutrient limitation, the addition of different types of (poly)phosphates to artificial seawater enhanced growth rates on fresh weight and area, but not on dry weight bases. Chlorophyll and internal P content were affected by P supply. In contrast, internal soluble reactive P was kept low and was little affected by P additions. Soluble protein content increased in all treatments, as ammonium was added to prevent N limitation. The C:N:P atomic ratio revealed great changes depending on the nutrient regime along the experiment. Cell extracts of U. pseudorotundata were capable of hydrolyzing polyphosphates of different chain lengths (pyro, tripoly, trimeta, and polyphosphates) at high rates. The sPPase activity was kept very low in P limited plants. Following N and different kind of P additions, sPPase activity was kept low in the control, but slightly stimulated after 3 days when expressed on a protein basis. The highest activities were found at the end of the experiment under pyro and polyphosphate additions (7 days). The importance of alternative P sources to phosphate and the potential role of internal soluble pyrophosphatases in macroalgae are discussed.

Experimental Investigation for Some Properties of PMMA Denture Base Strengthened by Different Nanoadditives

In dental and medical applications, poly-methyl methacrylate (PMMA) has been widely accepted due to the excellent biocompatibility and easy fabrication. Yet, some of the physical and mechanical characteristics of this compound are considered inferior. Seven groups of PMMA nano-composite samples were reported to be fabricated at laboratory temperature . These samples could be used in manufacturing the complete or partial maxillary denture base. The aim of this research is to prepare nano-composite materials which consist of PMMA as a matrix material and two different types of powder (prepared nanoparticles of SnO2 and natural egg shell powder (ESP)) as strengthening materials. The selected additives were used in many cases as pure or hybrid composites, specifically with weight percentage ratios of 1 and 2 wt%. Several analytical tests, namely AFM, FTIR, XRD and SEM, were used on the prepared nanoparticles. In addition, several tests were applied to assess the mechanical behavior before and after the reinforcement, including thermal conductivity, Vickers micro-Hardness, and water absorption. The results showed that the maximum amount of energy absorption in the composites was 1% at different types of additives, while a significant increase in thermal conductivity was recorded as the SnO2NPs percentage was increased. For surface micro-hardness, an obvious trend of increase was observed with the increase in additive percentage. The highest measured values of micro-hardness (19.59VHS and 13.30VHS) were recorded for the pure composites of 2% ESP and 2% SnO2, respectively. The results of water absorption test showed that higher percentages of ESP and SnO2, separately, within the pure composite resulted in higher water absorption capacity and an increased value of diffusion coefficient (D).

Abrasive Wear Resistance of Concrete in Connection with the Use of Crushed and Mined Aggregate, Active and Non-Active Mineral Additives, and the Use of Fibers in Concrete

Virtually every concrete structure comes into contact with abrasive effects of flowing media or solids, which have a direct impact on the durability of concrete. An abrasive effect is most pronounced in transport or water management structures, and these structures are often designed for a significantly longer service life (usually 100 years). This research evaluates the influence of the filler component in terms of the type of aggregate and its mineralogical composition on concrete abrasion resistance. As part of the impact of the binder component, several concrete mixtures were produced using the same aggregate and maintaining the same strength class with the addition of different types of active and inert mineral additives. In other parts of the research, the effect of adding fiber reinforcement on the abrasion resistance of concrete was verified. Mutual connections and correlations in different age groups (7, 28 and 90 days) were sought for all obtained results. The abrasion resistance of the composite was monitored by using standard procedures, especially using a Böhm device. It was found that for good abrasion resistance of concrete, it is not necessary to produce concretes with high strength classes using often expensive mineral additives (microsilica) and quality aggregates, but the maturation time of the composite and its microstructure plays an important role.

Formulation of a new polymer based on PP and PLA

The mixtures containing polypropylene are used in the industrial sector as material for bags, chairs, household items, and can even be used in cell phone batteries. The interest in creating this material is due to its low density compared to more common materials such as iron and ceramic, in addition to its good corrosion resistance and reasonable mechanical properties in environments without high temperature and pressure. In order to diversify the mechanical and viscous properties, different types of polymers were used, such as lactic polyacid, which has beneficial properties for recycling such as degradation. It is a challenge to control the right proportion and use additives and plasticizers to control the desired properties. The methods used to measure the properties of polypropylene and polylactic acid mixtures with different types of additives, compatibilizers and plasticizers were DMA, TGA, tensile, DSC and rheology tests following ASTM standards. The results were promising, observing different mechanical and viscosity properties for the PP/PLA/PP-g-MA/D mixture in different proportions. Thus concluding that the different products have varied application in the industry.

Determination of Free Diethanolamine Content

Abstract Quantification of alkanolamines is imperative for health and chemical safety risk reasons. A fast method that requires less equipment has been developed for the determination of free diethanolamine in different types of additives. Repeatability tests were carried out. The free diethanolamine content of commercially available additives has been determined. We have recommended industrial applicability.

Assessment Resistance Potential to Moisture Damage and Rutting for HMA Mixtures Reinforced by Steel Fibers

Rutting is mainly referring to pavement permanent deformation, it is a major problem for flexible pavement and it is a complicated process and highly observed along with many segments of asphalt pavement in Iraq. The occurrence of this defect is related to several variables such as elevated temperatures and high wheel loads. Studying effective methods to reduce rutting distress is of great significance for providing a safe and along-life road. The asphalt mixture used to be modified by adding different types of additives. The addition of additives typically excesses stiffness, improves temperature susceptibility, and reduces moisture sensitivity. For this work, steel fibres have been used for modifying asphalt mixture as they incorporated in the specimens by three percentages designated as 0.5, 1.0 and 1.5 % by the weight of asphalt mixture. The evaluation process based on conducting Marshall Test, Compressive strength test, and the wheel tracking test. The optimum asphalt content was determined for asphalt mixture. The results of the Marshall quotient and the index of retained strength of modified mixtures were increased by 44.0 and 17.38% respectively with adding 1.0% of steel fibres compared with the conventional mixture. The rut depth and dynamic stability were determined by using a wheel tracking test at two various testing temperatures of 45 and 55°C and two applied stresses of 70 and 80 psi. Results show that adding 1% of steel fibres to asphalt mixtures is very effective in increase the rutting resistance and reduce moisture damage.

Effects of half-sinusoidal nonuniform heating during MHD thermal convection in Cu–Al2O3/water hybrid nanofluid saturated with porous media

The intent of this study is to demonstrate an approach for augmenting heat transfer through porous media subjected to nonuniform heating during the magnetohydrodynamic flow of a hybrid nanofluid of Cu–Al2O3/water. The efficacy of such a heating technique is examined utilizing a classical flow geometry consisting of a square cavity. The heating is made at the bottom following a half-sinusoidal function of different frequencies, along with the presence of a uniform magnetic field. The thermal conditions of the cavity, particularly at the bottom wall, drive thermo-hydrodynamics and associated heat transfer. Furthermore, the addition of different types of nanoparticles to the base liquid in order to boost the thermal performance of conventional fluids and mono-nanofluids is a current technique. The coupled nonlinear governing equations are solved numerically in dimensionless forms adapting the finite volume approach, the Brinkman–Forchheimer–Darcy model, local thermal equilibrium and single-phase model. The study is conducted for wide ranges of parametric impacts to analyze global heat transfer performance. The results of this study reveal that the multi-frequency spatial heating during hybrid nanofluid flow can be utilized as a powerful means to improve the thermal performance of a system operating under different ranges of parameters, even with the presence of porous media and magnetic fields. In addition to different heating frequencies, the variations in amplitude (I) and superposed uniform temperature ( $$\theta_{\text{os}}$$ ) to half-sinusoidal heating are also examined thoughtfully in the analysis for different concentrations of Cu–Al2O3 nanoparticles. Compared to the base liquid, the hybrid nanofluid can contribute toward higher heat transfer.