scholarly journals Performance of Isolated Footings Reinforced Randomly by Glass Fiber

2019 ◽  
pp. 1-8
Author(s):  
Elsayed El Kasaby ◽  
Mohammad Farouk A. Bdelmagied
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Fatigue Properties ◽  
Structural Elements ◽  
Fiber Glass ◽  
Forming Process ◽  
Rectangular Shape ◽  
Concrete Crack ◽  
Reinforced Steel ◽  
Positive Effect

Fiber glass reinforced concrete (FGRC) is used form any structural elements due to its high mechanical properties, particularly flexural strength. As the concrete crack forming process accelerates and the probability of sudden fractures increases. There were various methods to eliminate this weakness of concrete. One of most common methods was employed of randomly distributed fiber. In this paper, two types of isolated footings were utilized, square and rectangular shape reinforced by a fiber glass with a length of 18 mm and having a rate of (0.20, 0.30, 0.35, 0.40, 0.50 and 1.00%) of weight, to experimentally investigate the tensile and fatigue properties of footings The results of FGRC were compared with the reinforced steel concrete. The results revealed that FGRC has a positive effect on the tensile and fatigue properties of isolated footing, especially with higher percentage of used fiber glass.

Effect of Carbon Nanotubes on Mechanical Properties of Cement Composites

2014 ◽  
Vol 915-916 ◽  
pp. 768-771
Author(s):  
Yun Feng Li ◽  
Jing Zhou ◽  
Lei Wen Gao
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Brittle Failure ◽  
Cement Composites ◽  
Toughness Index ◽  
Different Content ◽  
Positive Effect

Nanotubes exhibiting great mechanical properties are expected to produce significantly stronger and tougher cement composites. The effects of Carbon Nanotubes to cement based composites are investigated in this paper. The flexural strength and the compressive strength of the CNTs cement composites under different content of are tested and the toughness indexes are analyzed. The results show that CNTs have a positive effect on the brittle failure of cement composites, and that the compressive strength and flexural strength of 0.10% CNTs cement composites are significantly increased. The toughness index of 0.05% CNTs cement composites is relatively higher.

scholarly journals Influence of Microfibers Additive on the Self-healing Performance of Mass Concrete

2021 ◽  
Vol 39 (1A) ◽  
pp. 104-115
Author(s):  
Alaa Z. Dahesh ◽  
Farhad M. Othman ◽  
Alaa A. Abdul-hamead
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Physical And Mechanical Properties ◽  
Sem Analysis ◽  
Mass Concrete ◽  
Self Healing ◽  
Mixture Ratio ◽  
Concrete Mixtures ◽  
Strength Tests ◽  
Positive Effect

Because cracks are the main problem of mass concrete, this paper investigates an experimental study on the effect of polypropylene microfiber (PPMFs) on self -repair behavior of mass concrete, through study the microstructure, workability, physical, and mechanical properties of mass concrete. PPMFs with a diameter of 18 µm add in different percentages (0, 0.5, 1 and 1.5) % of cement weight. Where the prepared mixture ratio was (1:2:4.8) and the water-cement ratio (W/C) was 0.4. Also, 0.6% of Superplasticizer (SP) % of cement weight to all concrete mixtures was added. In this study, an SEM analysis used to observe the effect of PPMFs on the microstructure of mass concrete, and compressive and flexural strength tests for study the mechanical properties of this. And referring to the analysis and discussion of the results, PPMFs used have changed the microstructure of mass concrete, and have an effective effect on improving compressive strength and flexural strength, and mechanism of sealing the cracks of concrete autogenously. Also, 1% PPMFs (% of cement weight) recorded as the highest addition, which has a positive effect on mass concrete properties to apply it in the construction field.

scholarly journals Effects of TiO2 Nanoparticle Addition on Microstructure and Selected Properties of Ag–xTiO2 Composites

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4846
Author(s):  
Anna Wąsik ◽  
Beata Leszczyńska-Madej ◽  
Marcin Madej
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Nitrogen Atmosphere ◽  
Contact Boundary ◽  
Powder Metallurgy Method ◽  
Tem Analysis ◽  
Single Action ◽  
Steel Balls ◽  
Positive Effect ◽  
Made In

The paper presents the results of a study of the microstructure and selected properties of silver-based composites reinforced with TiO2 nanoparticles, produced by the powder metallurgy method. Pure silver powders were mixed with TiO2 reinforcement (5 and 10 wt%) and 5 mm steel balls (100Cr6) for 270 min in a Turbula T2F mixer to produce a homogeneous mixture. The composites were made in a rigid die with a single-action compaction press under a pressure of 400 MPa and 500 MPa and then sintered under nitrogen atmosphere at 900 °C. Additionally, to improve the density and mechanical properties of the obtained sinters, double pressing and double sintering operations were conducted. As a result, compacts with a density of 90–94% were obtained. The microstructure of the sintered compacts consists of uniform grains, and the TiO2 reinforcement phase particles are located on the grain boundaries. There were no discontinuities at the Ag–TiO2 contact boundary, which was confirmed by SEM and TEM analysis. The use of a higher pressure had a positive effect on the hardness and flexural strength of the tested materials. It was found that the composites with 5 wt% TiO2 pressed under 500 MPa are characterized by the highest level of mechanical properties. The hardness of these composites is 57 HB, while the flexural strength is 163 MPa.

scholarly journals Fatigue and fracture mechanical properties of selected concrete for subtle precast structural elements

2020 ◽  
Vol 310 ◽  
pp. 00033
Author(s):  
Stanislav Seitl ◽  
Petr Miarka ◽  
Vlastimil Bílek
Keyword(s):  
Mechanical Properties ◽  
Precast Concrete ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Structural Elements ◽  
Mechanical Fracture ◽  
Fatigue And Fracture ◽  
Natural Aggregates ◽  
Concrete Elements ◽  
Bearing Part

Precast concrete elements used as a civil structure are usually made of a cement-based matrix and natural aggregates (such as sand, gravel, crushed stone, etc.). These structures are usually exposed not only to a static load but also to a cyclic load if they load the bearing part of a bridge (traffic etc.). The knowledge of fatigue and fracture mechanical characteristics is important in designing and modelling new structures. This paper introduces and compares fracture mechanical properties obtained from static and fatigue tests for three kinds of concrete. The focus was set on the bulk density, flexural and compressive cube strength, fracture toughness and fatigue properties (S−N − Wöhler curve). All of these tests are important for a practical application in the design of precast concrete structures. The experimental results were statistically analysed and they showed that the fatigue and mechanical fracture properties improved with improved mechanical parameters of concrete.

Effects of Rare-Earth Oxides Doping on Microstructures and Properties of Al2O3/TiAl Composites

2011 ◽  
Vol 675-677 ◽  
pp. 143-146
Author(s):  
Fen Wang ◽  
Xiao Feng Wang ◽  
Jian Feng Zhu ◽  
Liu Yi Xiang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Rare Earth ◽  
Flexural Strength ◽  
Rare Earth Oxide ◽  
Rare Earth Oxides ◽  
Oxide Content ◽  
The Matrix ◽  
Al2o3 Particles ◽  
Positive Effect

Effects of rare-earth oxides addition (0.38~1.52 mol% of Sm2O3, Eu2O3 and Er2O3) on the property and microstructure of the hot-pressed (1300°C, 2h, 35 MPa) Al2O3 (12 wt %)/TiAl insitu composites have been investigated. The results show that the doping of rare-earth oxides has a positive effect on both mechanical properties and densities of Al2O3/TiAl composites. Densities enhanced with increasing of rare-earth oxides. The flexural strength and fracture toughness were higher than other samples when the rare-earth oxide content was 0.38 mol %. The matrix grains and Al2O3 particles were significantly refined, and Al2O3 particles evenly distributed in the matrix.

scholarly journals Flexural Strength Estimation for Hollow Cross-Section Simply Supported UHPC Beams

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nasser Hakeem Tu’ma ◽  
Mohammed Naji Hammood ◽  
Rasool Dakhil Mohsin
Keyword(s):  
Flexural Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Bottom Flange ◽  
Structural Elements ◽  
Ultra High Performance Concrete ◽  
Aspect Ratios ◽  
Flange Thickness ◽  
Strength Based ◽  
Reinforced Steel

Abstract The hollow structural elements occupy a great deal of researchers’ interest due to the possibility of losing their weights and maintaining or developing their resistances especially when increasing both compressive and tensile strength of modern materials. The flexural strength based on the forces balance and stain compatibility was derived. Nine beams of Ultra High Performance concrete (UHPC) and conventional reinforced steel bars were casted. Several parameters were taken which are the thickness of the concrete top flange, thickness of the concrete bottom flange, depth of the longitudinal hollow and the ratio of the longitudinal reinforcing steel. By comp aring the practical and theoretical results, the proposed flexural strength provided a safety factor of one-fifth against the experimental collected data. The ultimate flexural force developed up 260 % when increasing the reinforced steel area 4.6 times and 230 % comparing with the solid beam. Many aspect ratios were also mentioned that keep the strength in developing.

AL TECH POTOMAC A

Alloy Digest ◽  
1987 ◽  
Vol 36 (7) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Temperature ◽  
Tensile Ductility ◽  
Heat Treating ◽  
Fatigue Properties ◽  
Die Steel ◽  
Transverse Tensile ◽  
Temperature Performance ◽  
Specialty Steel

Abstract AL TECH POTOMAC A has well-balanced strength and toughness which make it especially suitable for a wide variety of hot-die steel applications, including those involving severe coolants. Its outstanding mechanical properties make it useful for many non-tooling requirements such as aerospace components. For more specialized needs, the manufacturer offers special melting processes that enhance this steel's fatigue properties and transverse tensile ductility. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, and machining. Filing Code: TS-478. Producer or source: AL Tech Specialty Steel Corporation.

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