Influence of Hydrothermal Nanosilica on Mechanical Properties of Plain Concrete

2017 ◽  
Vol 744 ◽  
pp. 126-130 ◽  
Author(s):  
Natalya Valentinovna Makarova ◽  
Vadim V. Potapov ◽  
Andrey V. Kozin ◽  
Evgeniy Anatolievich Chusovitin ◽  
Andrey V. Amosov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Lower Energy ◽  
Volume Fraction ◽  
Concrete Strength ◽  
Hydrothermal Solution ◽  
Plain Concrete ◽  
Energy Requirements ◽  
Detailed Characterization

The production of nanosilica (NS) from natural hydrothermal solution is an alternative to the existing commercial fabrication methods because of the lower energy requirements. Here we provide a detailed characterization of the main properties of NS samples (e.g., shape and particle size) by different methods. The produced NS has a specific surface area between 60 m2/g and 500 m2/g and nanoparticles sizes between 5 nm and 135 nm. The aim of the present work is to evaluate the effect of the natural NS on compressive strengths of plain concrete. For this purpose, eight series of concrete specimens with different volume fraction of NS are studied. Experimental results reveal that with adding of NS, the concrete strength can be increased by 35% after 28 days, whereas strength characteristics of such concrete can be increased up to 84% after 3 days, and 93% after 7 days compared with a control concrete without NS.

scholarly journals Amorphous Carbon Coatings for Total Knee Replacements—Part I: Deposition, Cytocompatibility, Chemical and Mechanical Properties

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1952
Author(s):  
Benedict Rothammer ◽  
Kevin Neusser ◽  
Max Marian ◽  
Marcel Bartz ◽  
Sebastian Krauß ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Amorphous Carbon ◽  
Detailed Characterization ◽  
Carbon Coatings ◽  
Dlc Coatings ◽  
Total Knee Replacements ◽  
Knee Replacements ◽  
Total Knee ◽  
Amorphous Carbon Coatings

Diamond-like carbon (DLC) coatings have the potential to reduce implant wear and thus to contribute to avoiding premature failure and increase service life of total knee replacements (TKAs). This two-part study addresses the development of such coatings for ultrahigh molecular weight polyethylene (UHMWPE) tibial inlays as well as cobalt–chromium–molybdenum (CoCr) and titanium (Ti64) alloy femoral components. While a detailed characterization of the tribological behavior is the subject of part II, part I focusses on the deposition of pure (a‑C:H) and tungsten-doped hydrogen-containing amorphous carbon coatings (a‑C:H:W) and the detailed characterization of their chemical, cytological, mechanical and adhesion behavior. The coatings are fabricated by physical vapor deposition (PVD) and display typical DLC morphology and composition, as verified by focused ion beam scanning electron microscopy and Raman spectroscopy. Their roughness is higher than that of the plain substrates. Initial screening with contact angle and surface tension as well as in vitro testing by indirect and direct application indicate favorable cytocompatibility. The DLC coatings feature excellent mechanical properties with a substantial enhancement of indentation hardness and elastic modulus ratios. The adhesion of the coatings as determined in modified scratch tests can be considered as sufficient for the use in TKAs.

scholarly journals The Mechanical Properties of Steel-Polypropylene Fibre Composites Concrete (HyFRCC)

2015 ◽  
Vol 773-774 ◽  
pp. 949-953 ◽  
Author(s):  
Izni Syahrizal Ibrahim ◽  
Wan Amizah Wan Jusoh ◽  
Abdul Rahman Mohd Sam ◽  
Nur Ain Mustapa ◽  
Sk Muiz Sk Abdul Razak
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Volume Fraction ◽  
Concrete Strength ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Polypropylene Fibre ◽  
Experimental Results

This paper discusses the experimental results on the mechanical properties of hybrid fibre reinforced composite concrete (HyFRCC) containing different proportions of steel fibre (SF) and polypropylene fibre (PPF). The mechanical properties include compressive strength, tensile strength, and flexural strength. SF is known to enhance the flexural and tensile strengths, and at the same time is able to resist the formation of macro cracking. Meanwhile, PPF contributes to the tensile strain capacity and compressive strength, and also delay the formation of micro cracks. Hooked-end deformed type SF fibre with 60 mm length and fibrillated virgin type PPF fibre with 19 mm length are used in this study. Meanwhile, the concrete strength is maintained for grade C30. The percentage proportion of SF-PPF fibres are varied in the range of 100-0%, 75-25%, 50-50%, 25-75% and 0-100% of which the total fibre volume fraction (Vf) is fixed at 0.5%. The experimental results reveal that the percentage proportion of SF-PPF fibres with 75-25% produced the maximum performance of flexural strength, tensile strength and flexural toughness. Meanwhile, the percentage proportion of SF-PPF fibres with 100-0% contributes to the improvement of the compressive strength compared to that of plain concrete.

STUDYING THE EFFECT OF DIFFERENT ADDITIVES ON THE THERMAL CONDUCTIVITY AND MECHANICAL CHARACTERISTICS OF EPOXY-BASED COMPOSITE MATERIALS

2021 ◽  
Vol 25 (Special) ◽  
pp. 2-72-2-77
Author(s):  
Hassanein M. Nhoo ◽  
◽  
Raad. M. Fenjan ◽  
Ahmed A. Ayash ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Particle Size ◽  
Tensile Strength ◽  
Mechanical Characteristics ◽  
Volume Fraction ◽  
Pyrolysis Process ◽  
Volume Percent ◽  
Fair Comparison ◽  
Filler Level

The current paper deals with investigating the effect of two different fillers on the thermal and mechanical characteristics of epoxy-based composite. The filler used throughout the study are: charcoal and Pyrex, both of them are different in nature and have not been investigated thoroughly or even compared fairly in terms of their effect on polymer matrix. Further, they can be considered as a cheap filler, charcoal can be obtained from a simple pyrolysis process of plants (charcoal) and Pyrex waste can be collected easily. Both types are added to the selected matrix with volume percent ranged from 10 to 60 with increments of 10. To ensure a fair comparison, the particle size is fixed (is about 1.7 micrometer). The results showed that the epoxy thermal conductivity has enhanced by about two orders of magnitudes over the studied range of filler. In terms of mechanical properties, the charcoal improves the tensile strength about 84% at 60% volume fraction while the Pyrex effect is about 40% at the same filler level. On the contrast, the results of compressive strength do not show an appreciable improvement overall. It decreases by about 12% at 60% volume fraction of charcoal while increases about the same percent with Pyrex at the same filler level.

scholarly journals Characterization of Airborne Particles Emitted During Application of Cosmetic Talc Products

2019 ◽  
Vol 16 (20) ◽  
pp. 3830 ◽  
Author(s):  
Pat Rasmussen ◽  
Christine Levesque ◽  
Jianjun Niu ◽  
Howard Gardner ◽  
Gregory Nilsson ◽  
...  
Keyword(s):  
Particle Size ◽  
Consumer Products ◽  
Airborne Particles ◽  
Aerodynamic Diameter ◽  
Breathing Zone ◽  
Direct Reading ◽  
Detailed Characterization ◽  
Adult Body ◽  
Reading Instruments

A pilot study was undertaken to characterize the concentration, duration and particle size distribution of the talc cloud that forms in the personal breathing zone (PBZ) during application of certain talc-containing cosmetics. Multiple direct-reading instruments were employed to simultaneously monitor PM4 concentrations (particulate matter with aerodynamic diameter < 4 µm; mg/m3) at different distances from each of three subjects while they applied talc products. Results indicated that the purpose and method of applying the talc product, combined with behavioral and physical differences amongst subjects, all strongly influenced airborne talc concentrations and the duration of the cloud. Air concentrations of talc in the PBZ averaged around 1.0 mg/m3, and the duration of exposure varied from less than one minute to more than ten minutes. The real-time monitors captured the occasional formation of secondary clouds, likely caused by resuspension of talc particles from skin or other surfaces. Measurements of aerosolized baby powder, face powder, and two adult body powders indicated that the median aerodynamic diameter of the talc cloud ranged from 1.7 to 2.0 µm. These direct-reading approaches were valuable for providing detailed characterization of short duration exposures to airborne talc particles, and will be useful to support future exposure assessments of talc and other powders in consumer products.

Experiment Research on Mechanical Properties and Penetration Performance of UHMWPE Fiber Concrete

2014 ◽  
Vol 989-994 ◽  
pp. 961-965 ◽  
Author(s):  
Yu Wu Zhang ◽  
Lu Hui Yan ◽  
Lin Zhu ◽  
Sheng Zhang ◽  
Ling Feng Li
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Plain Concrete ◽  
Fiber Volume ◽  
Uhmwpe Fiber ◽  
Remarkable Effect ◽  
Fiber Concrete ◽  
New Type ◽  
Beam Bending ◽  
Penetration Tests

The basic mechanical properties and penetration performance of a new type of fiber concrete reinforced by UHMWPE fiber were experimental investigated. The strengths of the cube compression, splitting tensile and beam bending of this FRC with four kinds of fiber volume fraction (FVF) was researched firstly. Then, the penetration tests for the FRC with FVF of 0.8% were then conducted. The results show that the UHMWPE fiber is of excellent effects to improve the tension strength and toughness of concrete. The penetration depth and cratering area of the FRC by bullet penetration are decreased obviously compared with plain concrete which testifies the remarkable effect of this kind of fiber on enhancing penetration resistance of concrete. Last but not least, the application prospect and field of UFRC were discussed.

Fabrication and Characterization of Particle Board from Coffee Husk Waste

2019 ◽  
Vol 891 ◽  
pp. 111-116 ◽  
Author(s):  
Nisakorn Nuamsrinuan ◽  
Patcharin Naemchanthara ◽  
Pichet Limsuwan ◽  
Kittisakchai Naemchanthara
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Wood Particle ◽  
Milling Process ◽  
Particle Board ◽  
Weight Percentage ◽  
Coffee Husk ◽  
Mechanical Properties Testing ◽  
Fabrication And Characterization

The purpose of this research was to fabricate the particle board from the coffee husk. The coffee husk from Chumphon province of Thailand was collected, prepared and separated into four groups such as outer husk, inner husk, the mixture of inner and outer husk and husk from the milling process. The coffee husk particle sheet was formed by the compression molding with the heater. Then the coffee husk particle sheets were the mechanical properties testing. The results showed the coffee husk particle sheet from milling process pass the Thai industrial standard (TIS.876/2547). However, the results of swelling and water absorption indicated that all the coffee husk sheet were not passed the TIS.876/2547. The effect of coffee husk particle size on mechanical properties was clarified. The coffee husk particle sheet from the particle size of 2, 4 and 6 mm was mechanical testing and follow TIS.876/2547. The coffee particle size of 2 mm showed the passing the standard. Moreover, the effect of isocyanate adhesive on mechanical properties was investigated. The weight percentage range of isocyanate adhesive on coffee husk from 7 to 13 %wt was carried out. The weight percentage of 9, 11 and 13 showed according to TIS.876/2547. From the experiment indicated that the coffee husk could be applied to the wood particle board industrial.

Size distribution and single particle characterization of airborne particulate matter collected in a silicon carbide plant

2019 ◽  
Vol 21 (3) ◽  
pp. 564-574 ◽  
Author(s):  
Torunn Kringlen Ervik ◽  
Nathalie Benker ◽  
Stephan Weinbruch ◽  
Yngvar Thomassen ◽  
Dag G. Ellingsen ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Particle Size ◽  
Particulate Matter ◽  
Size Range ◽  
Airborne Particulate Matter ◽  
Aerodynamic Diameter ◽  
Particle Characterization ◽  
Airborne Particulate ◽  
Detailed Characterization

A detailed characterization of particles as a function of particle size in the size range of 10 nm to 10 µm (aerodynamic diameter) collected from a silicon carbide plant in Norway.

Preparation and Characterization of WC Matrix Nanocomposite Cermet

2009 ◽  
Vol 628-629 ◽  
pp. 459-464 ◽  
Author(s):  
Fa Zhan Yang ◽  
Xing Ai ◽  
Jun Zhao
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Sintering Temperature ◽  
Fracture Morphology ◽  
Particle Sizes ◽  
Growth Inhibitors ◽  
Hot Press ◽  
Hot Press Sintering ◽  
Matrix Nanocomposite

A new WC matrix nanocomposite cermet was prepared by hot-press sintering. In the composite, certain amounts of VC is added to the composite as grain growth inhibitors. The consolidation is carried out under pressure 30～35Mpa and sintering temperature 1610°C for soaking 30min sintering. Microstructure of the nanocomposite cermet is scanned by SEM and mechanical properties are measured. It is detected that microstructure and fracture morphology is dissimilar to different particle sizes. Experimental results show that particle size of WC is important to the composite. Results show that relative density and hardness have the similar trend in growth. Meanwhile, the function of Al2O3 addition is also investigated in this paper.

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