scholarly journals Comparative Analysis on the Micropore and Microstructure Characteristics of Concrete under Insulated Formwork

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2862
Author(s):  
Myung-Kwan Lim ◽  
Kyung-Yong Nam
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Term Strength ◽  
Microstructure Characteristics ◽  
Hot Air ◽  
Chemical Admixture ◽  
Form Effect ◽  
Scanning Electron

During concrete construction in winter, the concrete performance is generally improved by adding a chemical admixture or providing protection using tents and hot-air blowers. However, long-term strength or safety accidents may occur due to the installation and removal of the tents. This study considered insulated gang forms to improve formwork methods. In this regard, the microstructure and micropore characteristics of concrete were investigated experimentally to examine the insulated gang form effect on the physical and mechanical properties of concrete. The micropore characteristics were investigated through scanning electron microscopy. The results confirm that applying insulated gangs improves workability and safety without adding chemical admixture. Moreover, the application of insulated gang forms reduces the use of tents and hot-air blowers. Therefore, insulated gangs provide excellent initial quality to the concrete.

scholarly journals New crosslinkers for electrospun chitosan fibre mats. I. Chemical analysis

2012 ◽  
Vol 9 (75) ◽  
pp. 2551-2562 ◽  
Author(s):  
Marjorie S. Austero ◽  
Amalie E. Donius ◽  
Ulrike G. K. Wegst ◽  
Caroline L. Schauer
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Mechanical Stability ◽  
Dissolution Tests ◽  
Natural Polysaccharide ◽  
Biomedical Field ◽  
The Stability ◽  
Scanning Electron

Chitosan (CS), the deacetylated form of chitin, the second most abundant, natural polysaccharide, is attractive for applications in the biomedical field because of its biocompatibility and resorption rates, which are higher than chitin. Crosslinking improves chemical and mechanical stability of CS. Here, we report the successful utilization of a new set of crosslinkers for electrospun CS. Genipin, hexamethylene-1,6-diaminocarboxysulphonate (HDACS) and epichlorohydrin (ECH) have not been previously explored for crosslinking of electrospun CS. In this first part of a two-part publication, we report the morphology, determined by field emission scanning electron microscopy (FESEM), and chemical interactions, determined by Fourier transform infrared microscopy, respectively. FESEM revealed that CS could successfully be electrospun from trifluoroacetic acid with genipin, HDACS and ECH added to the solution. Diameters were 267 ± 199 nm, 644 ± 359 nm and 896 ± 435 nm for CS–genipin, CS–HDACS and CS–ECH, respectively. Short- (15 min) and long-term (72 h) dissolution tests (T 600 ) were performed in acidic, neutral and basic pHs (3, 7 and 12). Post-spinning activation by heat and base to enhance crosslinking of CS–HDACS and CS–ECH decreased the fibre diameters and improved the stability. In the second part of this publication, we report the mechanical properties of the fibres.

SYNERGISTIC REINFORCEMENT OF ORGANOCLAY AND DOUBLE NETWORKING IN NATURAL RUBBER

2013 ◽  
Vol 86 (2) ◽  
pp. 205-217 ◽  
Author(s):  
Hedayatollah Sadeghi Ghari ◽  
Zahra Shakouri
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Natural Rubber ◽  
Physical And Mechanical Properties ◽  
X Ray Diffraction ◽  
Double Network ◽  
X Ray ◽  
Extension Ratio ◽  
Curing Characteristics ◽  
Scanning Electron

ABSTRACT Research was undertaken on natural rubber (NR) nanocomposites with organoclays. A double-network (DN) structure is formed when a partially cross-linked elastomer is further cross-linked during a state of strain. Two methods were used in the preparation of NR/organoclay nanocomposites: the ordinary method (single-network NR nanocomposite) and double-networked NR (DN-NR) nanocomposites. The single-networked NR nanocomposites were used for comparison. The effects of organoclay (5 phr) with a different extension ratio on curing characteristics, mechanical properties, hardness, swelling behavior, and morphology of single- and double-networked NR nanocomposites were studied. The results showed that double-networked NR nanocomposites exhibited higher physical and mechanical properties. The tensile strength of DN-NR nanocomposites increased up to 33 MPa (more than four times greater than that of pure NR) and then decreased with an increasing extension ratio. Modulus and hardness continuously increased with an increased extension ratio. The microstructure of the NR/organoclay systems was studied by X-ray diffraction and field emission scanning electron microscopy. The effects of different extension ratios on the dispersion of organoclay layers in the nanocomposites were investigated. Generally, results showed that the optimized extension ratio in DN nanocomposites was equal (or about or around) to α= 2.

scholarly journals Investigation of deformation and microstructure of bainite in Cu-9.97%Al-4.62%mn alloy

2014 ◽  
Vol 50 (1) ◽  
pp. 87-90 ◽  
Author(s):  
E. Aldirmaz ◽  
I. Aksoy
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Physical And Mechanical Properties ◽  
Compression Stress ◽  
X Ray Diffraction ◽  
Deformation Effect ◽  
X Ray ◽  
Deformation Test ◽  
Scanning Electron

In this study, some physical and mechanical properties in Cu-9.97%Al-4.62%Mn (wt%) alloy were investigated by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and compression deformation test. Bainite phase were obtained in the samples according to SEM and XRD analyses. Compression stress was applied on the alloy in order to investigate the deformation effect on the bainite phase transformation. On the surface of the Cu-9.97%Al-4.62%Mn alloy after the deformation, both bainite and martensite variants formed.

scholarly journals Physical and mechanical properties of membrane polyvinilidene flouride with the addition of silver nitrate

2018 ◽  
Vol 156 ◽  
pp. 08014
Author(s):  
Agung Mataram ◽  
S. Rizal ◽  
Estu Pujiono
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Silver Nitrate ◽  
Pore Diameter ◽  
Standardized Test ◽  
Physical And Mechanical Properties ◽  
Mixed Composition ◽  
Scanning Electron ◽  
Made In

The membrane is a layer formed from fine fibers are used as a filter. In this research, measured the tensile strength and pore size of the membrane that is made in three variations of a specimen with a mixed composition of different Polyvinilidene Fluoride 17.5%, 20%, 22.5%., membrane made using Polyvinilidene Fluoride polimer granules and N,N-Dimethylformamide as solvent and silver nitrate. Membrane molded into standardized test specimens and tested with a device Adhesion Tearring Strength Tester. The results show an increase in the value of the tensile test of 404.8356 KPa to the composition of 17.5%, 507.3598 KPa for composition of 20% and 603.7218 KPa to a composition of 22.5%. For testing the microstructure using a Scanning Electron Microscopy with the resulting increase in pore diameter, for the range of 558.4 nm-781.8 nm are void to the composition of 17.5%, range 670.1 nm - 781.8 nm without voids for the composition of 20% and 1.117 μm-1.228μm without voids on a composition of 22.5

scholarly journals PENGARUH LIMBAH ABU PEMBAKARAN BIOMASSA KELAPA SAWIT TERHADAP SIFAT-SIFAT FISIKA DAN MEKANIK HIGH IMPACT POLYSTYRENE

2015 ◽  
Vol 4 (3) ◽  
pp. 23-28
Author(s):  
Fadhilla Asyri ◽  
Kartini Noor Hafni ◽  
A. Haris Simamora
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Impact Strength ◽  
Specific Gravity ◽  
Physical And Mechanical Properties ◽  
High Impact ◽  
Elongation At Break ◽  
Scanning Electron

This study aims was to determine the effect of palm oil fuel ash (POFA) composite as filler on the physical and mechanical properties of high impact polystyrene (HIPS) composites. The research methodology included preparation of raw materials, treatment POFA (hydration process of POFA), mixing using tumbler and then extruder, molding composite specimens, and testing. The variables used were weight ratio of HIPS with 140 mesh POFA at 95/5; 92.5/7.5; 90/10. The composites were tested by Fourier Transform Infrared (FTIR), ash content, specific gravity, tensile strength, elongation at break, impact strength, hardness test, and Scanning Electron Microscopy (SEM). The results of FTIR characterization shows the formation of –OH bonding that was suspected as Si-OH or Si-hydrat. Results of physical and mechanical properties of the composites shows that increase of the filler composition in HIPS-POFA composites until the ratio of 90/10, increase the specific gravity to 7.2% of the original, tensile strength did not change significantly to 28.4 MPa, elongation at break decreased to 2.7%, impact strength decreased to 3.183 KJ/m2, and the hardness increased to 110.5, and Scanning Electron Microscopy (SEM) test show the transformation of POFA structure on treated POFA and intercalation between the matrix and POFA.

Effects of cellulose nanocrystals as extender on physical and mechanical properties of wood cement composite panels

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8291-8302
Author(s):  
Mona Shayestehkia ◽  
Habibollah Khademieslam ◽  
Behzad Bazyar ◽  
Hossein Rangavar ◽  
Hamid Reza Taghiyari
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Dry Weight ◽  
Cement Composite ◽  
Composite Panels ◽  
Microstructural Properties ◽  
Micro Structure ◽  
Mechanical And Microstructural Properties ◽  
Scanning Electron

The effects of cellulose nanocrystal (CNC) particles were investigated relative to the physical, mechanical, and microstructural properties of wood cement composite panels. Wood and cement were mixed at three ratios of 1:3, 1:3.5, and 1:4. Calcium chloride was added at 3 and 5%. CNC was added to the mixture at five levels (0, 0.1, 0.2, 0.5, and 1%, based on dry weight of cement). The results showed that CNC content of 0.5% had the best impact on the properties. The overall trend showed that with the addition of CNC, tensile, flexural, and physical properties of the composites were considerably enhanced. Scanning electron microscopy demonstrated that the addition of CNC was associated with an improved integrity in the micro-structure of panels.

Properties of Reactive Powder Concrete Using Densified Silica Fume

2013 ◽  
Vol 405-408 ◽  
pp. 2928-2932
Author(s):  
Krit Prasertlar ◽  
Krit Chaimoon
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Silica Fume ◽  
Physical And Mechanical Properties ◽  
Reactive Powder Concrete ◽  
Test Results ◽  
Cement Ratio ◽  
Reactive Powder ◽  
Different Characteristics ◽  
Scanning Electron

This paper presents some experimental results on the physical and mechanical properties of reactive powder concrete (RPC) using two different characteristics of densified silica fume (f1 and f2). The silica fume/cement ratio (f/c) varied from 15% to 35% by weight. The flow, the micromorphology by scanning electron microscopy (SEM) and the compressive strength at the ages of 3, 7 and 28 days were studied. The effects of the silica fume agglomerations on the properties of the RPC were considered and discussed. The test results indicated that the properties of RPC depended on the type of silica fume, amount of silica fume and amount of superplasticizer used.

scholarly journals Mechanical properties of titanium carbonitride reinforced alumina tool composites

Mechanik ◽  
2018 ◽  
Vol 91 (5-6) ◽  
pp. 438-442
Author(s):  
Magdalena Szutkowska ◽  
Marek Boniecki ◽  
Marcin Podsiadło ◽  
Andrzej Kalinka
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elevated Temperatures ◽  
Physical And Mechanical Properties ◽  
Young Modulus ◽  
Titanium Carbonitride ◽  
Pressureless Sintering ◽  
Alumina Composites ◽  
Scanning Electron

The present study reports mechanical properties obtained by reinforcing alumina composites with Ti(C,N) in amount 30 wt.% prepared on the basis micro and nanoscale trade powders. The pressureless sintering PS in a vacuum and SPS method of sintering were used. Vickers hardness, density, Young modulus, wear resistance were evaluated. Fracture toughness (KIC) at ambient and elevated temperatures up to 1073 K, characteristic for tool work was measured. Physical and mechanical properties of the composites Al2O3/Ti(C,N)/ZrO2 based on the powders in microscale were compared with composites containing nanoscale powders in a range from 17 to 36 wt.%. Tested composites with nanoscale powders content reveal lower KIC (approx. 10÷30%) at ambient temperature in comparison to composites based on powders in microscale. However, in the elevated temperatures their fracture toughness increases up to 30%. The observation of the microstructure of tested composites was carried out using scanning electron microscopy.

scholarly journals Microplasma surfacing on turbine blades

2020 ◽  
Vol 329 ◽  
pp. 03059
Author(s):  
Rashit Latypov ◽  
Mikhail Silensky ◽  
Gulnara Latypova
Keyword(s):  
Mechanical Properties ◽  
Turbine Blades ◽  
Base Material ◽  
Physical And Mechanical Properties ◽  
Combustion Products ◽  
Term Strength ◽  
Levels Of Automation ◽  
Plasma Surfacing ◽  
Modern Technologies

In modern technologies for the production of turbine blades, plasma surfacing processes of various levels of automation are increasingly used. Plasma surfacing is applied to the working surfaces of critical parts in order to obtain zones with special physical and mechanical properties or restore the specified geometric dimensions, correct defects in the base material, etc. The design of the turbine blades must meet all the requirements of the product’s service life, including long-term strength and creep, anti-friction characteristics under shock and alternating loads, corrosion resistance in fuel combustion products, etc. Plasma surfacing can help meet these requirements.

Lightweight Polyurethane Mortar with Structural Properties

2015 ◽  
Vol 1129 ◽  
pp. 581-585
Author(s):  
V. Calderón ◽  
Matthieu Horgnies ◽  
Raquel Arroyo ◽  
A. Rodríguez ◽  
S. Gutiérrez-González
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Mechanical Strength ◽  
Industrial Waste ◽  
Physical And Mechanical Properties ◽  
Axial Tomography ◽  
Computerized Axial Tomography ◽  
Reference Samples ◽  
Scanning Electron

Mortars made with Portland cement, sand, water and recycled polyurethane foam from industrial waste, including surfactants, are examined in this study. The research was carried out on the influences of the additives on the physical and mechanical properties of these recycled mortars. Results show that in spite of the porosity increase and apparent density decrease with the incorporation of polymer, mechanical strength remains enough or even higher than the reference samples that do not include polyurethane. Microstructure was analyzed by scanning electron microscopy (SEM), and the study was completed with a reconstruction of the macrostructure by Computerized Axial Tomography

Sign in / Sign up

Export Citation Format

Share Document