scholarly journals Experimental Investigation on Effect of Carbon Nanotubes and Carbon Fibres on the Behavior of Plain Cement Mortar Composite Round Bars under Direct Tension

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
A. M. Hunashyal ◽  
Sagar V. Tippa ◽  
S. S. Quadri ◽  
N. R. Banapurmath
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Fibers ◽  
Cement Mortar ◽  
Load Carrying Capacity ◽  
Direct Tension ◽  
Multiwalled Carbon ◽  
Strain Behavior ◽  
Load Carrying ◽  
Reinforced Cement ◽  
Deflection Criteria

This paper investigates the behavior of reinforced cement mortar composite round bars with multiwalled carbon nanotubes (MWCNTs) and carbon fibers (CFs). The percentage of CFs was fixed at 2.25 wt% of cement, while the percentage of MWCNTs was fixed at 0.5, by wt% of cement. Dispersion of both MWCNTs and CFs was carried out using ultrasonic energy method. Composite round bars were tested under direct tension in order to evaluate their mechanical properties such as ultimate load, deflection criteria, and stress-strain behavior. These results were then compared with the results of plain cement control round bars. From the study, it is shown that the load carrying capacity of composite bars under direct tension is substantially higher than the plain controlled bar.

scholarly journals FLEXURAL LOAD AND DEFLECTION BEHAVIOR OF STRUCTURAL BAMBOO FILLED WITH CEMENT MORTAR

2021 ◽  
Vol 83 (4) ◽  
pp. 31-39
Author(s):  
Gathot Heri Sudibyo ◽  
Nor Intang Setyo Hermanto ◽  
Hsuan-Teh Hu ◽  
Yanuar Haryanto ◽  
Laurencius Nugroho ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Carrying Capacity ◽  
Cement Mortar ◽  
Natural Material ◽  
Load Carrying Capacity ◽  
Structural Elements ◽  
Load Bearing ◽  
Four Point Bending ◽  
Bamboo Nodes ◽  
Load Carrying

Bamboo has been significantly and rapidly used to build temporal and permanent structures since time immemorial. However, this renewable natural material has a low bearing capacity, limiting its application to structures under light loads. Therefore, this research was carried out to determine an innovative scheme capable of enhancing bamboo's load-bearing by filling the cavity with cement mortar. Furthermore, a study was carried out to experiment flexural load carrying capacity and the deflection of mortar-filled structural bamboo by considering the diameter and node parameters. A total of 12 specimens were examined using a four-point bending protocol. The result showed the ultimate flexural load carrying capacity of mortar-filled bamboo specimens are higher than those of the conventional bamboo specimens. Specifically, mortar filled bamboo specimen with a diameter of 70 mm was significantly better, 41.10 and 47.06%, as compared than the conventional bamboo in terms of its flexural load carrying capacity for specimen without and with nodes, respectively. Increases in flexural load carrying capacity were also observed for the mortar-filled bamboo specimens having 80 and 90 mm diameter and these observed increases were recorded as 104.55 and 112.00%, and 48.72 and 60.74%, respectively for specimen without and with nodes. Furthermore, the deflection of mortar-filled bamboo elements are substantially greater than those of conventional. Finally, the advantages of the bamboo diameter and bamboo nodes on the flexural load carrying capacity indicated that these essential findings need to be carefully considered in designing structural elements for both mortar-filled and conventional bamboos.

scholarly journals Numerical Analysis of the Structural Stability of Ideal (Defect-Free) and Structurally and Morphologically Degenerated Homogeneous, Linearly- and Angle-Adjoined Nanotubes and Cylindrical Fullerenes Under Axial Loading Using Finite Element Method

2018 ◽  
Vol 10 (09) ◽  
pp. 1850100
Author(s):  
Sadegh Imani Yengejeh ◽  
Andreas Öchsner ◽  
Seyedeh Alieh Kazemi ◽  
Maksym Rybachuk
Keyword(s):  
Finite Element Method ◽  
Carbon Nanotubes ◽  
Finite Element ◽  
Critical Load ◽  
Structural Stability ◽  
Carrying Capacity ◽  
Axial Loading ◽  
Structural Defects ◽  
Load Carrying Capacity ◽  
Load Carrying

We report on the structural stability of ideal (defect-free) and structurally and morphologically degenerate carbon nanotubes and nanotube junction systems under axial loading based on the finite element method. We estimated the values for critical buckling load for uncapped and capped single-walled carbon nanotubes (SWCNTs) and linear and angle-adjoined SWCNT heterojunctions in ideal and structurally degenerate systems containing single-, double-, triple-, pinhole- and pentagon–heptagon (i.e., 5–7) structural defects and also containing a substitutional nitrogen (N) atom inclusion under compressive loading. Absolute atomic vacancy (defect) concentration in studied SWCNTs models was assumed to be nil for ideal systems, and was up to 3.0 at.% for structurally and morphologically degenerate systems. It was found that all types of structural defects and the morphological N-defect had reduced the load carrying capacity and mechanical strength in all SWCNT systems studied. The SWCNT models containing physically large vacant sites, such as triple- and pinhole-defects, displayed significantly lower critical load values compared to the systems that contained only a single-, double- or triple-vacancies. In addition, we found that capped SWCNTs performed marginally better in critical load carrying capacity compared to uncapped SWCNT systems. Furthermore, majority of the investigated structures displayed reduced load in SWCNTs with narrower tube widths, proportional to the size and the type of the defect investigated. The effects of chirality, such as zigzag- versus armchair-type, on the structural stability of the investigated SWCNT models were also investigated.

Experimental Tests on Strengthened Masonry Vaults

2014 ◽  
Vol 578-579 ◽  
pp. 1396-1399 ◽  
Author(s):  
Łukasz Hojdys ◽  
Piotr Krajewski
Keyword(s):  
Carbon Fiber ◽  
Glass Fiber ◽  
Failure Modes ◽  
Cement Mortar ◽  
Experimental Tests ◽  
Load Carrying Capacity ◽  
Lime Mortar ◽  
Clay Bricks ◽  
Load Carrying ◽  
Masonry Vaults

This paper reports and discusses the results of experiments performed on masonry barrel vaults strengthened externally with a composite material. The vaults characterized by 125-mm thickness, 2000-mm internal span and 730-mm rise, were built of solid clay bricks and lime mortar. As a strengthening glass fiber grids or carbon fiber grids were used. They were embedded in a polymer-cement mortar at the vaults extrados. The main aim of presented research was to determine load-carrying capacity and examine failure modes of tested specimens. The results of performed tests show that observed failure modes depended on reinforcement ratio of strengthening layer. The specimen strengthened with one layer of glass fiber grid failed due to fibers rupture, whereas the vault strengthened with carbon fiber grid failed due to sliding along a mortar joint just above the abutment.

scholarly journals CVD Synthesis of Hierarchical 3D MWCNT/Carbon-Fiber Nanostructures

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Toma Susi ◽  
Albert G. Nasibulin ◽  
Hua Jiang ◽  
Esko I. Kauppinen
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Fiber ◽  
Multiwalled Carbon Nanotubes ◽  
Carbon Fibers ◽  
Gas Flow ◽  
Carbon Precursor ◽  
Optimal Temperature ◽  
Multiwalled Carbon ◽  
Cvd Synthesis

Multiwalled carbon nanotubes (MWCNTs) were synthesized by CVD on industrially manufactured highly crystalline vapor-grown carbon fibers (VGCFs). Two catalyst metals (Ni and Fe) and carbon precursor gases (C2H2and CO) were studied. The catalysts were deposited on the fibers by sputtering and experiments carried out in two different reactors. Samples were characterized by electron microscopy (SEM and TEM). Iron was completely inactive as catalyst with bothC2H2and CO for reasons discussed in the paper. The combination of Ni andC2H2was very active for secondary CNT synthesis, without any pretreatment of the fibers. The optimal temperature for CNT synthesis was750∘C, with total gas flow of 650 cm3min⁡−1ofC2H2,H2, and Ar in 1.0:6.7:30 ratio.

scholarly journals Effect of Chases with Renovation Techniques on the Load Carrying Capacity of Masonry Walls

2021 ◽  
Vol 6 (11) ◽  
pp. 160
Author(s):  
Adnan Al-Sibahy ◽  
Rodger Edwards
Keyword(s):  
Carrying Capacity ◽  
Cement Mortar ◽  
Masonry Wall ◽  
Load Flow ◽  
Wire Mesh ◽  
Galvanized Steel ◽  
Small Scale ◽  
Masonry Walls ◽  
Load Carrying Capacity ◽  
Load Carrying

Infrastructure through the masonry walls (for example, wiring and piping works) are usually installed using chases in different directions. Introducing these chases in a newly built wall will affect its overall load carrying capacity. However, there has thus far been very limited research into the effects of chases on the response and load carrying capacity of walls. This study has been undertaken to evaluate the structural behaviour of new masonry walls having chases in both horizontal and vertical directions and subjected to compression load throughout an extensive experimental programme. In addition, two renovation techniques have been proposed to infill the chases created in small scale walls (wallettes). The first technique involved the use of plastic wire mesh and cement mortar, while the second incorporated using galvanized steel channel together with the plastic wire mesh and cement mortar. Furthermore, a reference case of wallette without chases has been considered to enable reasonable comparisons to check the effect of the chases and the efficiency of the proposed renovation techniques. The outcomes of this study were used to modify the design equations proposed in the relevant codes of practice. The obtained results showed a notable reduction in the load carrying capacity of the masonry wall due to the introduction of the chases with a reduction percentage of 29% compared to the masonry wall without chase. The percentage decrease depends on the depth of the chase and the inclination angle of the load flow. The walls with horizontal chases exhibited more reduction in the load carrying capacity compared to those with vertical chases. The adopted renovation techniques using galvanized steel channel and/or plastic wire mesh with cement mortar recovered 55% and 93% of the lost load carrying capacity due to the presence of the chase and the failure was due to the de-bonded phenomena of the infill materials. Suitable factors of safety have been proposed to be incorporated in the compressive strength and modulus of elasticity formulas of the masonry walls of the BS EN codes.

Incorporation of Carbon Nanotubes on Strategically De-Sized Carbon Fibers for Enhanced Interlaminar Shear Strength of Epoxy Matrix Composites

2019 ◽  
Vol 41 (4) ◽  
pp. 655-655
Author(s):  
Muhammad Abdul Basit Muhammad Abdul Basit ◽  
Sybt e anwar Qais Sybt e anwar Qais ◽  
Muhammad Saffee Ullah Malik and Ghufran Ur Rehman Muhammad Saffee Ullah Malik and Ghufran Ur Rehman ◽  
Faizan Siddique Awan Faizan Siddique Awan ◽  
Laraib Alam Khan and Tayyab Subhani Laraib Alam Khan and Tayyab Subhani
Keyword(s):  
Carbon Nanotubes ◽  
Shear Strength ◽  
Carbon Fibers ◽  
Epoxy Matrix ◽  
Interlaminar Shear Strength ◽  
Matrix Composites ◽  
Multiwalled Carbon ◽  
Shear Properties ◽  
Functionalized Multiwalled Carbon Nanotubes ◽  
Interlaminar Shear

Carbon fiber reinforced polymeric matrix composites are enormously used in aerospace and automotive industries due to their enhanced specific properties. However, the area of interlaminar shear properties still needs investigation so as to produce composites with improved through-the-thickness properties. To improve interlaminar shear properties of these composites, acid-functionalized multiwalled carbon nanotubes were deposited on de-sized carbon fibers through electrophoretic deposition. De-sizing of carbon fabric was performed through three different methods: furnace heating, acidic treatment and chloroform usage. As the acid-treatment provided better results than other two techniques, the acid-de-sized carbon fibers were coated with nanotubes and subsequently incorporated in epoxy matrix to prepare a novel class of multiscale composites using vacuum assisted resin transfer molding technique. Nearly 30% rise in the interlaminar shear strength of the composites was obtained which was credited to the coating of nanotubes on the surface of carbon fibers. The increased adhesion between carbon fibers and epoxy matrix due to mechanical interlocking of nanotubes was found to be the possible reason of improved interlaminar shear properties.

Tribological Behavior of Poly(ethylene Glycol)-Carbon Nanotubes

2011 ◽  
Vol 217-218 ◽  
pp. 688-691 ◽  
Author(s):  
Xue Feng Li ◽  
Han Yan ◽  
Shao Xian Peng
Keyword(s):  
Carbon Nanotubes ◽  
Ethylene Glycol ◽  
Flat Surface ◽  
Load Carrying Capacity ◽  
Poly Ethylene Glycol ◽  
Casting Technique ◽  
Spin Casting ◽  
Load Carrying ◽  
Nanocomposite Thin Films ◽  
Poly Ethylene

Poly(ethylene glycol)-carbon nanotubes (PEG-CNTs) were successfully prepared. Results of four-ball tribotester indicated that both the load-carrying capacity and anti-wear of the PEG-CNTs were superior to those PEG owing to the additive reinforced by CNTs. The nanocomposite thin films have been fabricated on mica by spin casting technique. AFM investigations provide insights into the roughness and microtribological properties on a micro scale. The polymer in the film is the guarantee of flat surface, and the rigid CNTs enhance load-bearing property of the thin film.

Sign in / Sign up

Export Citation Format

Share Document