scholarly journals Concrete reinforced with various amounts of steel fibers reclaimed from end-of-life tires

2019 ◽  
Vol 262 ◽  
pp. 06008 ◽  
Author(s):  
Małgorzata Pająk
Keyword(s):  
Compressive Strength ◽  
End Of Life ◽  
Steel Fibers ◽  
Geometrical Characteristic ◽  
Mechanical Parameters ◽  
Fresh State ◽  
Negative Effect ◽  
Flexural Tests ◽  
Concrete Reinforcement

The main objective of the paper was to provide more information about the influence of fibers coming from the end-of-life tires on the behaviour of concrete. Because of their untypical geometrical characteristic they are not eagerly applied as concrete reinforcement. Considering the amount of used tires, the management of this waste would he beneficial for the environment. The paper deals with the typical floor concrete reinforced with three dosages of fibers equal to: 30kg/m3, 40kg/m3 and 60kg/m3. The compressive and flexural mechanical parameters of RSFC were studied. The waste fibers with the shape dissimilar to manufactured fibers did not have a negative effect on the properties of the mix in a fresh state. The compressive strength was slightly affected by the fibers, meanwhile the pronounced influence of RSF on the post-peak flexural parameters was noted. Those parameters increased proportionally with the amount of fibers. However, the scatters in the flexural tests results were increasing with the fibers content. The investigations indicate that the fibers from the end-of-life tires could he applied as a concrete reinforcement. The values of flexural parameters which can be further applied to structural calculations were shown.

scholarly journals Strength and Toughness of Waste Fishing Net Fiber-Reinforced Concrete

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7381
Author(s):  
Tri N. M. Nguyen ◽  
Taek Hee Han ◽  
Jun Kil Park ◽  
Jung J. Kim
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Mechanical Strength ◽  
Brittle Material ◽  
Fiber Reinforced Concrete ◽  
Concrete Compressive Strength ◽  
Flexural Tests ◽  
Potential Efficiency ◽  
Concrete Reinforcement

In this study, we estimate the potential efficiency of waste fishing net (WFN) fibers as concrete reinforcements. Three WFN fiber concentrations (1, 2, and 3% by volume) were mixed with concrete. Compressive strength, toughness, splitting tensile strength, and biaxial flexural tests were conducted. Compressive strength decreased but other properties increased as a function of fiber proportions. According to the mechanical strength observations and the ductility number, WFN fibers yielded benefits in crack arresting that improved the postcracking behavior and transformed concrete from a brittle into a quasi-brittle material. It is inferred that WFN fiber is a recycled and eco-friendly material that can be utilized as potential concrete reinforcement.

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.    

An Investigation on Effect of Oil Palm Shell Ash on Flexural Strength and Compressive Strength of Cement Mortar

2014 ◽  
Vol 894 ◽  
pp. 55-59
Author(s):  
Abdoullah Namdar ◽  
Fadzil Mat Yahaya ◽  
Kok Jun Jie ◽  
Lim Yen Ping
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Oil Palm ◽  
Cement Mortar ◽  
Fine Sand ◽  
Time To Failure ◽  
Palm Shell ◽  
Oil Palm Shell ◽  
Negative Effect ◽  
Palm Oil Mill

One of waste agriculture materials is oil palm shell ash. It has been producing in high quantity in palm oil mill, and for storage of that an investment requires. In this paper, an attempt has been made to analysis effect of oil palm shell ash on compressive and flexural strength of cement mortar. The compressive strength and flexural strength of cement mortar has been measured. To improve accuracy of work 50% cement and 50% fine sand has been proposed in cement mortar mix design. The results have been indicated that the effect of OPS ash on flexural and compressive strength of cement mortar is not same. The deflection, load sustainability and time to failure for compressive strength have independent fluctuation of flexural strength. The positive and negative effect of OPS ash on mechanical properties of cement mortar has been observed. The morphology of crack failure has not been investigated. The work can be continued with many waste agriculture materials. Keywords: waste agriculture, deflection, load sustainability, time to failure.

Zaczyny cementowe z dodatkiem nanorurek węglowych do uszczelniania otworów wiertniczych o wysokiej temperaturze i ciśnieniu złożowym (150°C, 90 MPa)

Nafta-Gaz ◽  
2021 ◽  
Vol 77 (5) ◽  
pp. 323-331
Author(s):  
Miłosz Kędzierski ◽  
◽  
Marcin Rzepka ◽  
Keyword(s):  
Carbon Nanotubes ◽  
Compressive Strength ◽  
High Temperature ◽  
Rheological Parameters ◽  
External Diameter ◽  
Mechanical Parameters ◽  
Cement Slurry ◽  
Significant Information ◽  
High Temperature And Pressure ◽  
Temperature And Pressure

The article presents the results of the influence of carbon nanotubes on the mechanical parameters of cement stones under high temperature and pressure conditions (150°C, 90 MPa). The tests used multi-walled carbon nanotubes (MWCNTs) with an external diameter of 10–20 nm and a length of 10–30 μm. Cement slurries contained 0.1% of CNTs bwoc (by the weight of cement). Laboratory tests of cement slurries were carried out at the Oil and Gas Institute – National Research Institute. The tests were carried out under conditions of increased pressure and temperature at 150°C, 90 MPa. Cement slurries were prepared on the basis of class G drilling cement. Developing recipes were guided by the requirements to be met by cement slurry for the cementing of casing in the conditions of high temperature and reservoir pressures. The densities of tested slurries ranged from 1900 kg/m3 to 2250 kg/m3 (slurries with the addition of hematite). The cement slurries were tested for density, fluidity, rheological parameters, filtration and thickening time. Compressive strength tests and measuring adhesion were carried out after 2, 7, 14 and 28 days. Cement slurry recipes with very good technological parameters were developed and after curing (after 28 days of hydration) had very high values of compressive strength, reaching up to 45 MPa. Cements were characterized by high values of adhesion to pipes reaching up 7 MPa after 28 days. The research showed significant information about possible applications of carbon nanotubes to modify the cement slurry under conditions of high temperature and pressure. The conducted tests confirmed that the addition of even small amounts of CNTs improves the mechanical parameters of the cement stone compared to the base sample without such addition, and also reduces the thickening time of cement slurries and reduces filtration. It is investigated that CNTs addition increases the viscosity and yield point of cement slurry. As a result, slurries with the addition of MWCNTs will more effectively displace the mud from the borehole and significantly affect the quality of cementation.

scholarly journals Influence of Hybrid Fibers on Toughness Behavior of High Strength Flowing Concrete

2011 ◽  
Vol 57 (3) ◽  
pp. 249-260 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Hybrid Composite ◽  
High Strength ◽  
Steel Fibers ◽  
Hybrid Fibers ◽  
Static Modulus ◽  
Static Modulus Of Elasticity ◽  
Strength And Toughness

Abstract This study investigates the use of steel fibers and hybrid composite with a total fibers content of 2% on the high strength flowing concrete and determines the density, compressive strength, static modulus of elasticity, flexural strength and toughness indices for the mixes. The results show that the inclusion of more than 0.5% of palm fibers in hybrid fibers mixes reduces the compressive strength. The hybrid fibers can be considered as a promising concept and the replacement of a portion of steel fibers with palm fibers can significantly reduce the density, enhance the flexural strength and toughness. The results also indicates that the use of hybrid fibers (1.5 steel fibers + 0.5% palm fibers) in specimens increases significantly the toughness indices and thus the use of hybrid fibers combinations in reinforced concrete would enhance their flexural toughness & rigidity and enhance their overall performances

scholarly journals Effect of Incorporation of Rice Husk Ash Instead of Cement on the Performance of Steel Fibers Reinforced Concrete

2021 ◽  
Vol 8 ◽  
Author(s):  
Osama Zaid ◽  
Jawad Ahmad ◽  
Muhammad Shahid Siddique ◽  
Fahid Aslam
Keyword(s):  
Compressive Strength ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Steel Fibers ◽  
Concrete Compressive Strength ◽  
Brittle Behavior ◽  
Direct Combustion ◽  
Low Performance ◽  
Strength And Durability ◽  
Reference Samples

The production of rice is significant worldwide; the husk produced is generally used as a combustible material for the preparation of paddies, delivering energy through direct combustion as well as by gasifying. Annually, 7.4 million tons of Rice Husk Ash (RHA) is produced and poses an incredible danger to the environment, harming the land and the encompassing zone where it is unloaded. In the transformation of rice husk to ash, the ignition cycle eliminates the natural products, leaving silica-rich remains. These silica-rich remains have proven to have potential to be utilized in concrete as a limited substitution of cement to enhance the concrete compressive strength. Steel fibers’ incorporation increases the concrete tensile strength, balances out concrete samples, and changes their brittle behavior to a more ductile response. In the current study, the influence of various doses of Rice Husk Ash (RHA) used in concrete in the presence and absence of steel fibers and concrete performance has been examined. A total of nine mixes have been designed: one was a control, four were without steel fibers containing only RHA, and the last four mixed RHA with steel fibers from 0.5 to 2%. Tests with 5, 10, 15, and 20% percentages of RHA replacing the concrete have been targeted. Results have been compared with the reference samples and the reasonability of adding Rice Husk Ash to concrete has been studied. From the results, it was noted that about 10% of cement might be replaced with Rice Husk Ash mixed in with steel fibers with almost equal compressive strength. Replacing more than 15% of cement with RHA will produce concrete with a low performance in terms of strength and durability.

scholarly journals The Influence of Replacing Sand with Waste Glass Particle on the Physical and Mechanical Parameters of Concrete

2018 ◽  
Vol 4 (7) ◽  
pp. 1646
Author(s):  
Hamed Dabiri ◽  
Mohammad Kazem Sharbatdar ◽  
A. Kavyani ◽  
M. Baghdadi
Keyword(s):  
Compressive Strength ◽  
Glass Particle ◽  
Waste Glass ◽  
Waste Materials ◽  
Alkali Silica Reaction ◽  
Colored Glass ◽  
Mechanical Parameters ◽  
Practical Solution ◽  
Compressive Strength Of Concrete ◽  
Harmful Effects

Glass is a special type of materials which is widely used in various forms and colors for different usages. Colored bottles comprise a large part of waste glass. To reduce the destructive effects of waste glass on the environment, it might be recycled. However, some indecomposable waste materials are buried. This will have harmful effects on the environment. A practical solution for reducing non-recyclable waste colored glass is using them as replacements for materials in other industries such as concrete industry. The effect of replacing aggregate with waste glass particle on the compressive strength and weight of concrete is investigated in this study. To achieve the goal, totally 27 cubic specimens were created; 6 specimens were made of concrete, while waste glass particle was added to the mix of other specimens. To prevent Alkali Silica Reaction (ASR), Microsilica was added to the mix of specimens containing glass. Generally, Results indicated that replacing aggregate with glass particle more than 30% lead to increment in compressive strength of concrete. The weight of concrete remains almost the same in all of the specimens. Briefly, based on the results it could be concluded that the optimum percentage for replacing aggregate with glass particle is 50%.

scholarly journals Justifiability of Euthanasia and Related Practices among Common Russians: In search of Determinants

2019 ◽  
Vol 25 (1) ◽  
pp. 72-97
Author(s):  
Maksim G. Rudnev
Keyword(s):  
End Of Life ◽  
Personal Autonomy ◽  
Explanatory Power ◽  
Unexpected Result ◽  
Weak Support ◽  
Life Issues ◽  
Negative Effect ◽  
End Of Life Issues ◽  
Trust In Physicians ◽  
Proximity To Death

The aging of the population during the twentieth century sparked a discussion on end-of-life issues and particularly voluntary life termination due to unbearable suffering (euthanasia and related practices). Most of the euthanasia attitude studies have been focused on groups directly involved in end-of-life issues, such as physicians and patients. This article investigates the typical views of common Russians in regard to euthanasia and related practices, and looks for their determinants. A survey of 1201 respondents in 2014 was conducted using a probabilistic sample representing the population of Russia. Measurement of euthanasia justifiability included descriptions of patients’ conditions and types of life termination procedures. Analysis of the results showed that basic values were important predictors of euthanasia justifiability. However, a model derived from international and western research failed to confirm this. Our hypothesis regarding the relations between values of autonomy and justification of euthanasia found only weak support, while benevolence values demonstrated a strong negative effect. Proximity to death showed a negative effect: the fact of caring for sick close ones, as well as one’s own ill-health, were related to a lower justification of euthanasia. Religiosity demonstrated only marginally significant coefficients. Contrary to our hypothesis, interactions between death proximity indicators and trust in physicians and people in general were insignificant. Another unexpected result was a negative link between confidence in the healthcare system and euthanasia justifiability. We attribute these findings to a “priestly” model of care prevalent among Russians; the characteristic structuring of values among Russians, in which care for others contradicts personal autonomy; as well as endorsement of avoidance over approach motivations. In conclusion we list the limitations of the study and point out the weak explanatory power of the models presented.

Mechanical Performances of Green Engineered Cementitious Composites Incorporating Various Types of Sand

2019 ◽  
Vol 821 ◽  
pp. 512-517
Author(s):  
Siong Wee Lee ◽  
Chai Lian Oh ◽  
Mohd Raizamzamani Md Zain ◽  
Norrul Azmi Yahya ◽  
Azerai Ali Rahman
Keyword(s):  
Compressive Strength ◽  
Recycled Concrete ◽  
Cementitious Composites ◽  
Flexural Stress ◽  
Engineered Cementitious Composites ◽  
River Sand ◽  
Granulated Blast Furnace Slag ◽  
In Series ◽  
Mechanical Performances ◽  
Flexural Tests

This paper evaluates the mechanical performances of green engineered cementitious composites (ECC) by means of compressive strength and flexural behaviour. Green ECC made of cement, ground granulated blast-furnace slag (GGBS), river sand or recycled concrete fine (RCF), polypropylene (PP) fiber, water and superplasticizer (SP) was employed in this study. Compression test result implies that green ECC incorporating either sieved river sand or sieved RCF (below 600 μm) in series G60 and G70 exhibited greater compressive strength compared with green ECC with unsieved river sand. In series G80, compressive strength of green ECC was not affected by RCF content. Flexural stress-mid deflection curves demonstrated that all green ECC specimens performed more ductile compared to normal concrete as they undergone large deformation capacity after the first cracking strength. Both compression and flexural tests suggested that mixture G80SRCF0.4 containing large amount of sieved RCF and least amount of cement is the best green ECC mixture in this study.

Evaluation of Mechanical Behavior and Microstructural Characteristics of Photocatalytic Concretes to Be Used as Pavement Blocks

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
João Victor Staub de Melo ◽  
Glicério Trichês
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Mechanical Behavior ◽  
Tio2 Nanoparticles ◽  
Modulus Of Elasticity ◽  
Microstructural Characteristics ◽  
State Tests ◽  
Fresh State ◽  
Hardened State ◽  
Microstructural Behavior

This paper reports the results obtained in a study on the effect of the addition of TiO2 nanoparticles on the mechanical properties and microstructural characteristics of photocatalytic concretes. In the hardened state, tests to determine the compressive strength and modulus of elasticity were carried out. Also, microstructural aspects of the samples were investigated. In the fresh state, the influence of the addition of TiO2 on the concrete compaction and conduction calorimetry curves was evaluated. The results obtained indicated a better mechanical and microstructural behavior of concrete with addition of TiO2.

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