Effect of Discarded Steel Fibers on Impact Resistance, Flexural Toughness and Fracture Energy of High-Strength Self-Compacting Concrete Exposed to Elevated Temperatures

2020 ◽  
pp. 103271
Author(s):  
Saif K. Mezzal ◽  
Zaid Al-Azzawi ◽  
Khalid B. Najim
Keyword(s):  
Fracture Energy ◽  
Elevated Temperatures ◽  
Impact Resistance ◽  
High Strength ◽  
Steel Fibers ◽  
Self Compacting Concrete ◽  
Flexural Toughness

scholarly journals Impact Performance of Steel Fiber-Reinforced Self-Compacting Concrete against Repeated Drop Weight Impact

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 91
Author(s):  
Sallal R. Abid ◽  
Murali Gunasekaran ◽  
Sajjad H. Ali ◽  
Ahmed L. Kadhum ◽  
Thaar S. Al-Gasham ◽  
...  
Keyword(s):  
Steel Fiber ◽  
Impact Resistance ◽  
High Strength ◽  
Steel Fibers ◽  
Test Results ◽  
Fiber Reinforced ◽  
Self Compacting Concrete ◽  
Impact Performance ◽  
Free Falling ◽  
The Impact

The self-compacting concrete (SCC) was invented to overcome the compaction problems in deep sections, owing to its perfect workability characteristics. Steel fibers when used with SCC would affect the required fluidity characteristics but improve its impact resistance. In this research, an experimental work was conducted to evaluate the impact response of micro-steel fiber-reinforced SCC, under flexural impact. A 5.47 kg free-falling mass was dropped repeatedly from 100 mm height on the top center of 270 mm-length beam specimens. Eight mixtures with two design grades of 30 and 50 MPa were prepared to distinguish the normal and high-strength SCCs. The distinguishing variable for each design grade was the fiber content, where four volumetric contents of 0%, 0.5%, 0.75%, and 1.0% were used. The test results showed that the impact resistance and ductility were significantly improved due to the incorporation of micro-steel fibers. The percentage improvements were noticeably higher at failure stage than at cracking stage. For the 30 MPa mixtures, the maximum percentage improvements at cracking and failure stages were 543% and 836%, respectively. Weibull’s linear correlations with R2 values of 0.84 to 0.97 were obtained at the failure stage, which meant that the impact failure number followed the Wiebull distribution.

Mechanical and Basic Physical Properties of High-Strength Concrete Exposed to Elevated Temperatures

2018 ◽  
Vol 760 ◽  
pp. 108-113 ◽  
Author(s):  
Lenka Scheinherrová ◽  
Monika Čáchová ◽  
Michaela Petříková ◽  
Lukáš Fiala ◽  
Eva Vejmelková ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Structural Changes ◽  
Elevated Temperatures ◽  
Water Environment ◽  
High Strength ◽  
Steel Fibers ◽  
Quartz Powder ◽  
Matrix Density ◽  
Drying Treatment

In this paper, the effect of elevated temperatures on the mechanical and basic properties of two different newly-designed high-strength concretes is studied. The studied materials were prepared from Portland cement, steel fibers, reactive finely milled quartz powder and quartz sand, silica fume, plasticizer, and with a relatively low water/cement ratio of 0.24. The samples were stored in water environment for the first 28 days of hydration to achieve better mechanical properties. Then, after pre-drying at 105 °C to constant mass, the materials were exposed to elevated temperatures of 600 °C and 1000 °C where they were kept for 2 hours. The basic physical properties, such as matrix density, bulk density and open porosity were determined as a function of temperature. Mechanical properties (compressive and flexural strength) were also studied. The measured parameters exhibited a high dependence on temperature and the obtained results pointed to the structural changes of the studied materials. Spalling was not observed because of the pre-drying treatment.

A Review on Ductile Self-Compacting Concrete

2013 ◽  
Vol 594-595 ◽  
pp. 433-438
Author(s):  
Muhd Fadhil Nuruddin ◽  
Kok Yung Chang ◽  
Norzaireen Mohd Azmee ◽  
Nasir Shafiq
Keyword(s):  
High Strength Concrete ◽  
High Performance ◽  
Lightweight Concrete ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Self Compacting Concrete ◽  
Factors Influencing ◽  
Recent Innovation ◽  
High Performance Fiber

Ductile self-compacting concrete (DSCC) also known as ultra-high-performance fiber reinforced concrete with a steel like compressive strength of up to 250 MPa and remarkable increase in durability compared to high-strength concrete can be considered as the most successful recent innovation in concrete construction. The achievement of DSCC has been made possible by the introduction of materials such as superplasticizers, microsilica and steel fibers. Incorporation of steel fibers in the mix made it feasible to design sustainable filigree, lightweight concrete constructions without any additional steel reinforcement. The purpose of this paper is to review the needs of DSCC and the factors influencing the workability of DSCC as well as the effect of the inclusion of steel fibers. Various studies concluded that the inclusion of steel fibers will increase the mechanical and durability properties but reduce the workability.

scholarly journals Effect of Steel Fiber Aspect Ratio on the Properties of High Strength Self Compacting Concrete

2019 ◽  
Vol 9 (2) ◽  
pp. 2938-2941
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Steel Fibers ◽  
Self Compacting Concrete ◽  
Split Tensile Strength ◽  
Strength Concrete ◽  
Fiber Aspect Ratio ◽  
Aspect Ratios ◽  
Hardened Properties

The High strength concrete defined as per IS 456 as the concrete having characteristic compressive strength more than 65 MPa. The self-compacting concrete has lot of advantages including concreting at congested reinforcement locations, better finish, good compaction etc. The inclusion of fibers in the concrete mix decreases the brittle nature of concrete thereby the ductility increases. Different types of fibers are available for inclusion in concrete like steel, glass, polypropylene, basalt, etc. In the present investigation, high strength concrete having characteristic strength of 90 MPa was developed and hooked ended steel fibers are used and the hardened properties are determined. Steel fibers having diameter of 1 mm and lengths of 25 and 50 mm were added to concrete in 0.125%, 0.25% and 0.5% by volume of concrete. Three hardened properties compressive strength, split tensile Strength and flexural strength were determined. Out of the two lengths of fiber i.e with two aspect ratios, the fiber with 50 mm length yielded better results.

COMPARISON OF FRESH AND HARDENED PROPERTIES OF SELF-COMPACTING CONCRETE MIXTURE FROM DIFFERENT ASPECT RATIO OF STEEL FIBER VIEW POINT

2021 ◽  
Vol 16 (1) ◽  
pp. 115-138
Author(s):  
Hassane Amidou Ouedraogo ◽  
Süleyman Özen ◽  
Veysel Kobya ◽  
Serkan Sagiroglu ◽  
Ali Mardani-Aghabaglou
Keyword(s):  
Aspect Ratio ◽  
Fracture Energy ◽  
Modulus Of Elasticity ◽  
Dynamic Properties ◽  
Crack Opening ◽  
Steel Fibers ◽  
Time Dependent ◽  
Self Compacting Concrete ◽  
Depth Of Penetration ◽  
Aspect Ratios

ABSTRACT Self-compacting concrete (SCC) is a type of concrete which is frequently preferred in different applications due to its advantages such as its fluidity and transition in tight openings between steel reinforcing bars. However, it is vital that SCC maintains its fresh state characteristics when its transportation phase is taken into consideration. Fiber reinforced in SCC affects the properties of fresh concrete negatively while it had a positive effect on its dynamic properties. In this study, the effect of steel fibers having different aspect ratios on the time dependent fresh properties and mechanical properties of self-compacting concrete mixtures was investigated. In addition to the control mixture without fiber, in the mixtures containing fiber, three different twin-hook steel fibers with aspect ratios of 54, 64 and 50 were used as 0.6% of total volume. In all of the SCC mixtures, the water/cement ratio, cement dosage and slump-flow value were kept constant. The time dependent rheological properties of the mixtures were investigated. The compressive, split-tensile and flexural strengths as well as fracture energy, the load deflection relation under flexural load and load-crack opening displacement, modulus of elasticity of SCC mixtures were also investigated. Besides, the water absorption capacity and depth of penetration of water under pressure of mixtures were measured. On the basis of the results, the fiber utilization and its aspect ratio had no significant effect on compressive strength and modulus of elasticity of the SCC mixtures. The split-tensile, flexural strengths and fracture energy of SCC mixtures increased by using fiber; the permeability properties of SCC mixture increased by fiber utilization.

Relationship between Impact Energy and Flexural Toughness Energy of Steel Fiber Reinforced Lightweight Aggregate Concrete

2011 ◽  
Vol 261-263 ◽  
pp. 385-388
Author(s):  
Hai Tao Wang ◽  
Jin Qing Jia
Keyword(s):  
Impact Energy ◽  
Impact Resistance ◽  
Lightweight Aggregate ◽  
Steel Fibers ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Flexural Toughness ◽  
Drop Weight ◽  
Flexural Tests ◽  
The Impact

In order to determine the impact resistance of lightweight aggregate concrete (LWC), especially the effect of steel fibers on impact resistance of LWC, a series of drop-weight tests, recommended by the ACI committee 544, have been carried out in the present study. Impact and flexural tests were carried out on lightweight aggregate concrete reinforced with five different percentages of steel fibers 0.0%, 0.5%, 1.0%, 1.5% and 2.0% by volume of concrete. For each volume of fibers, complete load–deflection curves of SFLWC were generated in order to determine the total energy absorbed for each specimen. The addition of steel fibers to concrete has improved impact resistance and also the flexural toughness. The test results showed that a logarithmic relation exists between flexural toughness energy by means of the generated load–deflection curves from the flexural tests and the impact energy by means of drop-weight tests.

scholarly journals Fire Performance of Heavyweight Self-Compacting Concrete and Heavyweight High Strength Concrete

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 822 ◽  
Author(s):  
Farhad Aslani ◽  
Fatemeh Hamidi ◽  
Qilong Ma
Keyword(s):  
Compressive Strength ◽  
Mass Loss ◽  
Modulus Of Elasticity ◽  
High Strength Concrete ◽  
Elevated Temperatures ◽  
High Strength ◽  
Self Compacting Concrete ◽  
Strength Concrete ◽  
Magnetite Content ◽  
Hardened State

In this study, the fresh and hardened state properties of heavyweight self-compacting concrete (HWSCC) and heavyweight high strength concrete (HWHSC) containing heavyweight magnetite aggregate with 50, 75, and 100% replacement ratio, and their performance at elevated temperatures were explored experimentally. For fresh-state properties, the flowability and passing ability of HWSCCs were assessed by using slump flow, T500 mm, and J-ring tests. Hardened-state properties including hardened density, compressive strength, and modulus of elasticity were evaluated after 28 days of mixing. High-temperature tests were also performed to study the mass loss, spalling of HWSCC and HWHSC, and residual mechanical properties at 100, 300, 600 and 900 °C with a heating rate of 5 °C/min. Ultimately, by using the experimental data, rational numerical models were established to predict the compressive strength and modulus of elasticity of HWSCC at elevated temperatures. The results of the flowability and passing ability revealed that the addition of magnetite aggregate would not deteriorate the workability of HWSCCs and they retained their self-compacting characteristics. Based on the hardened densities, only self-compacting concrete (SCC) with 100% magnetite content, and high strength concrete (HSC) with 75 and 100% magnetite aggregate can be considered as HWC. For both the compressive strength and elastic modulus, decreasing trends were observed by introducing magnetite aggregate to SCC and HSC at an ambient temperature. Mass loss and spalling evaluations showed severe crack propagation for SCC without magnetite aggregate while SCCs containing magnetite aggregate preserved up to 900 °C. Nevertheless, the mass loss of SCCs containing 75 and 100% magnetite content were higher than that of SCC without magnetite. Due to the pressure build-up, HSCs with and without magnetite showed explosive spalling at high temperatures. The residual mechanical properties analysis indicated that the highest retention of the compressive strength and modulus of elasticity after exposure to elevated temperatures belonged to HWSCC with 100% magnetite content.

scholarly journals Hybrid Effects of Stirrup Ratio and Steel Fibers on Shear Behaviour of Self-Compacting Concrete

2018 ◽  
Vol 64 (1) ◽  
pp. 145-169
Author(s):  
Praveen Kannam ◽  
Venkateswara Rao. Sarella ◽  
Rathish Kumar Pancharathi
Keyword(s):  
Failure Mode ◽  
Mechanical Behaviour ◽  
Shear Failure ◽  
Ultimate Load ◽  
Steel Fiber ◽  
High Strength ◽  
Steel Fibers ◽  
Shear Behaviour ◽  
Self Compacting Concrete ◽  
Shear Cracking

Abstract Shear cracking behaviour of fibrous self-compacting concrete of normal and high strength grade (M30 and M70) is presented here. Two stirrup diameters (6mm ∅ and 8 mm ∅) with a constant steel fiber content of 38 kg/m3 (0.5% by volume of concrete) were selected for the present study. The size of the beam was fixed at 100x200x1200mm. The clear span of the beam 1100mm, was maintained throughout the study. A total of 16 shear-deficient beams were tested under three point loading. Two stirrup spacing (180mm and 360 mm) are used for the shear span-to-depth ratio (a/d = 2). Investigation indicates that initial cracking load and ultimate load increased as the area of shear reinforcement increased by increasing the diameter of stirrup. It was also noted that the failure mode was modified from brittle shear failure to flexural-shear failure in the presence of fibers. The mechanical behaviour of SFRSCC was improved due to the combined effect of stirrups and steel fibers. The stiffness, toughness, and deflection of the beams increased when compared to SCC beams without fibers. The experimental results were compared with existing models available in literature, and the correlation is satisfactory.

Sign in / Sign up

Export Citation Format

Share Document