The effects of silica fume and polypropylene fibers on the impact resistance and mechanical properties of concrete

2010 ◽  
Vol 24 (6) ◽  
pp. 927-933 ◽  
Author(s):  
Mahmoud Nili ◽  
V. Afroughsabet
Keyword(s):  
Mechanical Properties ◽  
Silica Fume ◽  
Impact Resistance ◽  
Polypropylene Fibers ◽  
The Impact

SHPB Dynamic Experiment on Silica Fume Concrete

2013 ◽  
Vol 631-632 ◽  
pp. 771-775 ◽  
Author(s):  
Rong Jun Chen ◽  
Hong Wei Liu ◽  
Rui Zeng
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Silica Fume ◽  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Impact Resistance ◽  
Dynamic Mechanical Properties ◽  
Hopkinson Pressure Bar ◽  
The Impact

Dynamic mechanical properties of silica fume concrete in a number of strain rate under the conditions of dynamic compression mechanical properties subjected to various strain rates were studied, and gained the stress versus strain curves, details of an experimental investigation using 74 mm-diameter split Hopkinson pressure bar(SHPB) apparatus were presented. The results showed that: The admixture of silica fume concrete impact resistance, especially under the impact of the performance of high-speed has a very important influence, with the impact velocity increased, the strain rate increase, and its impact more obvious.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

scholarly journals Effect of SWCNT-Tuball Paper on the Lightning Strike Protection of CFRPs and Their Selected Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3140
Author(s):  
Kamil Dydek ◽  
Anna Boczkowska ◽  
Rafał Kozera ◽  
Paweł Durałek ◽  
Łukasz Sarniak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Copper Foil ◽  
Impact Resistance ◽  
Mechanical Analysis ◽  
Lightning Strike ◽  
Single Wall Carbon Nanotubes ◽  
Carbon Fibre Reinforced Polymer ◽  
The Impact

The main aim of this work was the investigation of the possibility of replacing the heavy metallic meshes applied onto the composite structure in airplanes for lightning strike protection with a thin film of Tuball single-wall carbon nanotubes in the form of ultra-light, conductive paper. The Tuball paper studied contained 75 wt% or 90 wt% of carbon nanotubes and was applied on the top of carbon fibre reinforced polymer before fabrication of flat panels. First, the electrical conductivity, impact resistance and thermo-mechanical properties of modified laminates were measured and compared with the reference values. Then, flat panels with selected Tuball paper, expanded copper foil and reference panels were fabricated for lightning strike tests. The effectiveness of lightning strike protection was evaluated by using the ultrasonic phased-array technique. It was found that the introduction of Tuball paper on the laminates surface improved both the surface and the volume electrical conductivity by 8800% and 300%, respectively. The impact resistance was tested in two directions, perpendicular and parallel to the carbon fibres, and the values increased by 9.8% and 44%, respectively. The dynamic thermo-mechanical analysis showed higher stiffness and a slight increase in glass transition temperature of the modified laminates. Ultrasonic investigation after lightning strike tests showed that the effectiveness of Tuball paper is comparable to expanded copper foil.

Phase Morphology, Thermal and Mechanical Properties of Compatibilized Nylon12/Natural Rubber Blends Using PS/MNR

2013 ◽  
Vol 844 ◽  
pp. 53-56
Author(s):  
Saravalee Saengthaveep ◽  
Sadhan C. Jana ◽  
Rathanawan Magaraphan
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Moisture Absorption ◽  
Rubber Particle ◽  
Impact Resistance ◽  
Phase Morphology ◽  
Thermal And Mechanical Properties ◽  
Binary Blend ◽  
Polyamide 12 ◽  
The Impact

To produce a tough material for application demanding high impact resistance and low moisture absorption, melt blending of Nylon12 (Polyamide 12, PA12) and natural rubber (NR) was carried out in a brabender plasticorder at 210 °C with rotor speed of 70 rpm in the presence of polystyrene/maleated natural rubber (PS/MNR) blend as a compatibilizer. The effect of compatibilizer content (1, 3, 5, 7 and 10 phr) on phase morphology, thermal, and mechanical properties of [Nylon12/NR]/[PS/MNR] blends was investigated by using SEM, DSC, and Izod impact tester, respectively. The result revealed that PS/MNR blend improved the compatibility of Nylon12/NR blends efficiently due to the presence of amide linkage at the interfaces from the reaction between the reactive groups of MNR and the NH2 end groups of Nylon12 during mixing. A fine phase morphology (good dispersion and small dispersed phase size of NR domains in Nylon12 matrix) of [Nylon12/NR]/[PS/MNR] blends was observed at the optimum compatibilizer content of 7 phr, relating to the improvement of mechanical property. The impact energy of [Nylon12/NR]/[PS/MNR] blends was 503 J/m higher than that of neat Nylon12 (115 J/m) and Nylon12/NR binary blend (241 J/m) due to the toughening effect of rubber and proper morphology. The melting temperature of all blends did not change obviously from thermal analysis. However, the presence of rubber particle obstructed the crystallization of Nylon12 phase, leading to the decreasing of %crystallinity from 93% to around 70%.

scholarly journals Effect of Three-dimensional Printing with Nanotubes on Impact Resistance

2019 ◽  
Author(s):  
Anne Schmitz
Keyword(s):  
Mechanical Properties ◽  
Lower Limb ◽  
Impact Resistance ◽  
Three Dimensional ◽  
Three Dimensional Printing ◽  
Impact Tester ◽  
The Impact ◽  
Dimensional Printing ◽  
Pendulum Impact ◽  
Pendulum Impact Tester

Abstract The types of biomedical devices that can be three-dimensional printed (3DP) is limited by the mechanical properties of the resulting materials. As a result, much research has focused on adding carbon nanotubes (CNT) to these photocurable polymers to make them stronger. However, there is little to no data on how CNTs affect the impact resistance of these polymers, an important property when designing and manufacturing lower limb prosthetics. The objective of this study was to expand the use of 3DP to prosthetics by testing the hypothesis that adding CNTs to a stereolithographic (SLA) photocurable resin will result in a cured polymer with increased impact resistance. Twenty-six total specimens: 13 with nanotubes and 13 without nanotubes, were printed on a Form2 SLA printer. Once all the specimens were printed, washed, and cured, the impact resistance was quantified using a pendulum impact tester in a notched Izod configuration. Contrary to the hypothesis, the specimens with SWCNTs (0.312 ± 0.036 ft*lb/in) had a significantly lower impact resistance compared to the non-SWCNT specimens (0.364 ± 0.055 ft*lb/in), U = 34.0, p = 0.004. This decreased impact resistance may be due to voids in the printed polymer around the aggregated nanotubes. Thus, SLA polymers still do not have the impact strength needed to be used for a full lower limb prosthetic.

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