scholarly journals Waste Tire Particles and Gamma Radiation as Modifiers of the Mechanical Properties of Concrete

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Eduardo Sadot Herrera-Sosa ◽  
Gonzalo Martínez-Barrera ◽  
Carlos Barrera-Díaz ◽  
Epifanio Cruz-Zaragoza
Keyword(s):  
Mechanical Properties ◽  
Gamma Radiation ◽  
Chemical Properties ◽  
Plain Concrete ◽  
Cement Matrix ◽  
Portland Cement Concrete ◽  
High Concentration ◽  
Good Tool ◽  
Waste Tire ◽  
Physical And Chemical

In polymer reinforced concrete, the Young’s modulus of both polymers and cement matrix is responsible for the detrimental properties of the concrete, including compressive and tensile strength, as well as stiffness. A novel methodology for solving such problems is based on use of ionizing radiation, which has proven to be a good tool for improvement on physical and chemical properties of several materials including polymers, ceramics, and composites. In this work, particles of 0.85 mm and 2.80 mm obtained from waste tire were submitted at 250 kGy of gamma radiation in order to modify their physicochemical properties and then used as reinforcement in Portland cement concrete for improving mechanical properties. The results show diminution on mechanical properties in both kinds of concrete without (or with) irradiated tire particles with respect to plain concrete. Nevertheless such diminutions (from 2 to 16%) are compensated with the use of high concentration of waste tire particles (30%), which ensures that the concrete will not significantly increase the cost.

Study of Whiskers to be Used in Composite Materials

2021 ◽  
Vol 316 ◽  
pp. 51-55
Author(s):  
Tamara I. Shishelova ◽  
Vadim V. Fedchishin ◽  
Mikhail A. Khramovskih
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Chemical Properties ◽  
High Strength ◽  
Rapid Expansion ◽  
Physical And Chemical Properties ◽  
Reinforcement Fiber ◽  
Object Of Study ◽  
Physical And Chemical ◽  
And Chemical Properties

Rapid expansion of technologies poses higher requirements to structural materials and items made of them. Conventional materials are being replaced by composite materials (composites). Different additives enhancing the properties of initial materials are used as reinforcement fibers of composites. Utilization of micro-and nanosize particles for production of present-day materials is paid much attention to. Whiskers are among such materials. These crystals have high strength, high chemical and temperature resistance. But for rational utilization of whickers of different chemical composition in composite materials one should know their physical and chemical properties. Objectives of the paper: to study physical and chemical properties of whiskers in different compounds, their composition and structure; to prove experimentally the feasibility of utilizing whiskers as a reinforcement fiber of composite materials. Object of study: specimens of whiskers of silicon nitride (Si3N4), aluminum oxide (Al2O3), aluminum nitride (AlN), and mullite (Al6Si2O13). Methods of investigation: thermal study of specimens, study of mechanical properties and chemical strength, and IR-spectroscopy. Results of study: specimens of whiskers have been studied and their mechanical properties have been tabulated for comparison. Extensive thermal investigation was followed by deduction of regularities and identification of chemical properties of whiskers. IR-spectra of whiskers have been studied and conclusions on molecular composition and on presence of impurities in some whiskers have been made.

scholarly journals Biocompatible Material from Indonesian Natural Resource of Wild Silkmoth Cocoon

2018 ◽  
Vol 1 (2) ◽  
pp. 47
Author(s):  
Tjokorda Gde Tirta Nindhia ◽  
Zdenek Knejzlík ◽  
Tomáš Ruml ◽  
I Wayan Surata ◽  
Tjokorda Sari Nindhia
Keyword(s):  
Mechanical Properties ◽  
Natural Resource ◽  
Chemical Properties ◽  
Hot Water ◽  
Physical And Chemical Properties ◽  
Living Things ◽  
Biocompatibility Testing ◽  
Good Biocompatibility ◽  
Physical And Chemical ◽  
And Chemical Properties

Silk can be produced by spider or insect and have prospect as biomaterial for regenerative healing in medical treatment. Silk having physical and chemical properties that support biocompatibility in the living things..In this research, silk that was obtained from Indonesia natural resource of Attacus atlas silkmoth was explored and then will be  developed for biocompatible biomaterial. The treatment with NaOH was developed to separate the fiber from the cocoon. The obtained fiber is investigated its mechanical property by performing tensile test for single fiber. The biocompatibility testing was conducted with human cell (osteosarccoma) cultivation. The result identify that separation by using NaOH yield better better mechanical properties comparing konvenstional method with boiling in hot water. Biocompatibility testing indicate that the the fiber having good biocompatibility.

scholarly journals Sustainable low-carbon binders and concretes

2020 ◽  
Vol 166 ◽  
pp. 06007
Author(s):  
Myroslav Sanytsky ◽  
Tetiana Kropyvnytska ◽  
Stanislav Fic ◽  
Hanna Ivashchyshyn
Keyword(s):  
Activity Index ◽  
Chemical Properties ◽  
High Volume ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Cement Matrix ◽  
Low Carbon ◽  
Blended Cements ◽  
Physical And Chemical

Sustainable development depends on a consistency of interests, social, ecological and economic, and that the interests are evaluated in a balanced manner. In order to reduce CO2 emissions, the conception of decreasing clinker factor and increasing the role of supplementary cementitious materials (SCMs) in the cementitious materials has high economical and environmental efficiency. The performance of clinkerefficient blended cements with supplementary cementitious materials were examined. The influence of superfine zeolite with increased surface energy on the physical and chemical properties of low-carbon blended cements is shown. Increasing the dispersion of cementitious materials contributes to the growth of their strength activity index due to compaction of cement matrix and pozzolanic reactions in unclincker part. In consequence of the early structure formation and the directed formation of the microstructure of the cement matrix is solving the problem of obtaining clinker-efficient concretes. Shown that low-carbon blended cements with high volume of SCMs are suitable, in principle, for producing structural concretes.

Dispersion of Multi-Walled Carbon Nanotubes in Portland Cement Concrete Using Ultra-Sonication and Polycarboxylic Based Superplasticizer

2015 ◽  
Vol 802 ◽  
pp. 112-117 ◽  
Author(s):  
Ali Yousefi ◽  
Norazura Muhamad Bunnori ◽  
Mehrnoush Khavarian ◽  
Taksiah A. Majid
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Portland Cement ◽  
Cement Matrix ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Uniform Dispersion ◽  
Multi Walled Carbon Nanotubes ◽  
Sonication Technique ◽  
Walled Carbon Nanotubes

The potential properties of carbon nanotube-cement based materials strongly depend on the dispersion of carbon nanotubes (CNTs) within the cement matrix and the bonding between CNTs and the hydrated cement. The homogeneous dispersion of CNTs in the cement matrix yet is one of the main challenges due to strong van der Waals forces between nanotubes. In this study, a polycarboxylic ether based superplasticizer and ultra-sonication technique was used for dispersion of multi-walled carbon nanotubes (MWCNTs). Portland cement concrete specimens with different concentrations of MWCNTs (0.04 and 0.1 % by the weight of cement), with and without the presence of superplasticizer were investigated. Compressive strength test results revealed a significant improvement in mechanical properties of sample containing 0.1 % MWCNTs and 0.2 % superplasticizer. Moreover, field emission scanning electron microscopy (FESEM) images of fractured surfaces of hardened specimens showed a good dispersion of MWCNTs within the cement matrix. This method was developed to facilitate the uniform dispersion of MWCNTs in the cementitious concrete for better reinforcement in nanoscale and mechanical properties enhancement by transfer of load between the nanotubes and matrix.

Influence of Fluidized Fly Ash on the Selected Physical-Mechanical Properties of the Autoclaved Aerated Concrete

2014 ◽  
Vol 899 ◽  
pp. 409-414 ◽  
Author(s):  
Alena Struhárová ◽  
Stanislav Unčík ◽  
Svetozár Balkovic ◽  
Mária Hlavinková
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Amorphous Phases ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete ◽  
Free Cao ◽  
Physical And Chemical ◽  
And Chemical Properties

Fluidized fly ash has different physical and chemical properties compared to fly ash emerging from classic combustion. It contains amorphous phases resulting from a dehydration of clay minerals as well as unreacted sorbent of CaCO3, free CaO and anhydrite (CaSO4). Work targets the possibilities of production of an autoclaved aerated concrete (AAC) from fluidized fly ash, and its influence on particular physical-mechanical properties of autoclaved aerated concrete.

scholarly journals Effect of Copper (II) Sulfate on the Properties of Urea Formaldehyde Adhesive

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 94
Author(s):  
Hui Zhao ◽  
Xianzhen Li ◽  
Xi Wang ◽  
Mianwu Meng ◽  
Xiujian Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Urea Formaldehyde ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Sulfate Content ◽  
Formaldehyde Release ◽  
Uf Resin ◽  
Effect Of Copper ◽  
Physical And Chemical ◽  
And Chemical Properties

The purpose of this work is to investigate the effects of copper (II) sulfate on formaldehyde release and the mechanical properties of urea formaldehyde (UF) adhesive. Copper (II) sulfate has been used as a formaldehyde scavenger in UF resin, and its effects on the physical and chemical properties of UF adhesive have been studied. Moreover, the mechanical properties and formaldehyde release of plywood prepared with modified UF resin have been determined. The UF resin has been characterized by Fourier-transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). FTIR spectra showed that the addition of copper (II) sulfate to the UF resin did not affect the infrared (IR) absorptions of its functional groups, implying that the structure of UF was not modified. Further results showed that: the free formaldehyde content of the UF resin by the incorporation of 3% copper (II) sulfate was 0.13 wt.%, around 71% lower than that of the control UF adhesive. With a copper (II) sulfate content of 3%, the formaldehyde release from treated plywood was 0.74 mg·L−1, around 50% lower than that from the control UF adhesive, and the bonding strength reached 1.73 MPa, around 43% higher than that of the control UF adhesive.

scholarly journals ADIATION SHIELDING EFFECT OF BASALT CONCRETE; AN EXPERIMENTAL APPROACH

2020 ◽  
Vol 15 (11) ◽  
Author(s):  
Engr. Furqan Wali
Keyword(s):  
Gamma Radiation ◽  
Experimental Approach ◽  
Coarse Aggregate ◽  
Chemical Properties ◽  
Shielding Effect ◽  
Coarse Aggregates ◽  
Water To Cement Ratio ◽  
Physical And Chemical ◽  
Specific Reason ◽  
And Chemical Properties

This paper presents an assessment of gamma radiation performance, specifically in terms of attenuation energy, of concrete containing coarse aggregate having different physical and chemical properties. Basalt being heavier and somehow having high specific gravity is likely to have a good performance against gamma radiation. Through this paper, the author has made a comparison between the concrete having different coarse aggregates, normal aggregate phase and basaltic aggregate phase by evaluating the attenuation energies of both the phases at the Institute of Radiotherapy and Nuclear Medicine (IRNUM) Peshawar. Also, the water to cement ratio (W/C) for both the phases was distinguished i.e. 3.5 and 5.7 to make the results more promising and enabling to make the comparison effective. The test was likely to be conducted on Molds having 10 cm by 10 cm cross-section of each W/C ratio with varying thickness of about 2cm and will lead up to 10cm. The detecting device used was a phoenix teletherapy machine operating with a former type ionization chamber having an energy of 1.25 MeV. The source of radiation was Cobalt 60. The results indicated that basalt despite having strong physical properties is insufficient to be used for Gamma shielding. The two materials vary very little, so it is negligible to be used for a specific reason.

scholarly journals Comparative Analysis of Structure and Properties of Stereoscopic Cocoon and Flat Cocoon

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bin Zhou ◽  
Huiling Wang ◽  
Hongtao Zhou ◽  
Ke Wang ◽  
Shudong Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Properties ◽  
Morphological Characteristics ◽  
Morphological Structure ◽  
Variable Structure ◽  
Fiber Fineness ◽  
The Common ◽  
Physical And Chemical ◽  
Structure And Functions ◽  
And Chemical Properties

Abstract Cocoon is a kind of natural biopolymer material with reasonable structure and various functions. However, its structure and functions are often destroyed in practical application. In this study, we took common Bombyx Mori as the research object, and provided different cocooning sites for single or multiple silkworms to construct common stereoscopic cocoons (“normal cocoons” [NC]) and flat cocoons (“single-silkworm flat cocoons” [SFC] and “multi-silkworm flat cocoons” [MFC]), respectively, and compared the morphological structure and basic properties of these cocoons. The study found that the flat cocoons have similar multi-layered variable structure and characteristics compared to those of the common cocoons; also, morphological characteristics and physical and chemical properties of silk fiber from outer layer to inner layer, such as sericin content, fiber fineness, and change rule of basic mechanical properties, are completely consistent with those of the common cocoons. It can be considered that the flat cocoons are constructed by silkworms in the same “procedural” process as that of common cocoons. Due to the expansion of cocooning space, the mechanical properties of fibers are significantly improved. By controlling the size of the cocooning space or the quantity of silkworms cocooning simultaneously, and the time of spinning, a cocoon material with controllable thickness, weight per square meter, porosity, and number of cocoon layers can be obtained as a composite material for direct application.

scholarly journals Investigate the mechanical properties of Si/Ge (Ge/Si) core-shell nanowires: A molecular dynamics study

2020 ◽  
Vol 3 (4) ◽  
pp. first
Author(s):  
Vuong Van Thanh ◽  
Tran The Quang ◽  
Nguyen Tuan Hung ◽  
Vu Le Huy ◽  
Do Van Truong
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Elastic Modulus ◽  
Lattice Mismatch ◽  
Chemical Properties ◽  
Core Shell ◽  
The Core ◽  
Axial Tensile ◽  
Physical And Chemical ◽  
And Chemical Properties

Nanowires (NWs) have been used increasingly in practice due to their outstanding mechanical, physical, and chemical properties. In this paper, we use the molecular dynamics (MD) method to investigate the mechanical properties of NWs (Si/Ge, Ge/Si) with a core-shell structure under the axial tensile strain along the <100>/{100} direction. Our results show that the strength and elastic modulus of Ge/Si and Si/Ge NWs depend on the composition and size of the core/shell crosssection. The strength and strain of Ge/Si NW decrease with increasing the size of the core crosssection because of the lattice mismatch between two layers of core/shell materials. The elastic modulus of Ge/Si NWs increases with the increasing the size of the core cross-section, while the elastic modulus of the Si/Ge NW decreases. In addition, the theoretical strength and elastic modulus of Ge/Si NWs reduce with the growth of the temperature. Furthermore, we also investigate the effect of strain rate on the mechanical properties of the Ge/Si NWs. The obtained results of the study provide the intrinsic properties of the core-shell NWs and also help in the design and fabrication of electronic and optical devices based on the Ge/Si NWs.

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