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.

Experimental Study on the Shear Behavior of Fiber Reinforced Self-Compacting Concrete Rectangular Beams

2014 ◽  
Vol 934 ◽  
pp. 65-70
Author(s):  
Zhi Guo You ◽  
Yun Long Zhou ◽  
Long Chao Yang ◽  
Peng Wang
Keyword(s):  
Failure Mode ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Steel Fibers ◽  
Shear Load ◽  
Experiment Study ◽  
Hybrid Fiber ◽  
Self Compacting Concrete ◽  
Hybrid Fibers ◽  
Better Than

The main purpose of this paper is the analysis of the influence of steel fiber and hybrid fiber on the ultimate shear load and failure mode of rectangular concrete beams. The results of this experiment study indicate that fibers can enhance the ultimate shear load. Hybrid fibers can change the failure mode. The mechanical behavior of beam with hybrid fibers is better than that with mono-steel fibers.

scholarly journals Shear Failure Mode and Concrete Edge Breakout Resistance of Cast-In-Place Anchors in Steel Fiber-Reinforced Normal Strength Concrete

2020 ◽  
Vol 10 (19) ◽  
pp. 6883
Author(s):  
Jong-Han Lee ◽  
Eunsoo Choi ◽  
Baik-Soon Cho
Keyword(s):  
Flexural Strength ◽  
Failure Mode ◽  
Shear Failure ◽  
Steel Fiber ◽  
Shear Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Embedment Depth ◽  
Fiber Reinforced ◽  
Tensile Performance

Concrete edge failure of a single anchor in concrete is strongly dependent on the tensile performance of the concrete, which can be greatly improved by the addition of steel fibers. This study investigated the effect of steel fibers on the shear failure mode and edge breakout resistance of anchors installed in steel fiber-reinforced concrete (SFRC) with fiber volume percentages of 0.33, 0.67, and 1.00%. The anchor used in the study was 30 mm in diameter, with an edge distance of 75 mm and embedment depth of 240 mm. In addition to the anchor specimens, beam specimens were prepared to assess the relationship between the tensile performance of SFRC beams and the shear resistance of SFRC anchors. The ultimate flexural strength of the beam and the breakout shear resistance of the anchor increased almost linearly with increasing volume fractions of fiber. Therefore, based on the ACI 318 design equation, a term was proposed using the ultimate flexural strength of concrete instead of the compressive strength to determine the concrete breakout shear resistance of an anchor in the SFRC. The calculated shear resistance of anchors in both the plain concrete and SFRC were in good agreement with the measurements. In addition to the load capacity of the SFRC anchors, the energy absorption capacity showed a linear increase with that of the SFRC beam.

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.

scholarly journals Strength And Durability Properties Of Steel Fiber Reinforced Self Compacting Concrete

2021 ◽  
Vol 12 (5) ◽  
pp. 818-826
Author(s):  
Sumith Vangara, S Siva Rama Krishna, Venu Malagavelli, K.Tarunkumar, A. Jagadish Babu
Keyword(s):  
Steel Fiber ◽  
Design Procedure ◽  
Steel Fibers ◽  
Second Phase ◽  
Initial Surface ◽  
Fiber Reinforced ◽  
Acid Attack ◽  
Self Compacting Concrete ◽  
Surface Absorption ◽  
Durability Properties

In this present study the durability characteristics of Steel fiber reinforced Self compacting concrete (SFRSCC) is determined for M30 and M40 grade concrete mixes. Along with durability strength and sorptivity is carried out and comparison is made with Plane self-compacting concrete (SCC) by chemical resistances, Initial Surface Absorption Test (ISAT). In the present study, the rational mix design procedure for self-compacting concrete is used. SCC mixes contains large quantity of powder (material whose parcel size is 0.125 mm) to maintain the plastic yield of the properties of fresh concrete as per the general guidelines for design of SCC mixes given in the EFNARC (2005). The present project consists of two phases. In the first phase, SCC mixes for different grades are developed without steel fibers and with steel fibers. The mechanical properties like compressive strength of the different grades were studied. In the second phase, based on the experimental results, durability properties were studied with the using of specimens of size 100 mm × 100 mm × 100 mm. Durability studies like Acid attack factors, Acid-Durability factors, Sulphate attack factors, Sorptivity are studied for the Plain SCC and steel Fiber Reinforced SCC and a comparison is made.

scholarly journals An Analytical and Numerical Investigation on Punching Shear Behaviour of SCC Slab

2016 ◽  
Vol 3 (3) ◽  
Author(s):  
V. Kavinkumar ◽  
R. Elangovan
Keyword(s):  
Shear Stress ◽  
Shear Failure ◽  
Shear Capacity ◽  
Punching Shear ◽  
Shear Behaviour ◽  
Slab Thickness ◽  
Failure Zone ◽  
Self Compacting Concrete ◽  
Concentrated Load ◽  
Different Thickness

<div><p><em>This research is to study the mechanical properties of Self Compacting Concrete (SCC) as well as punching shear failure of SCC slabs. Self compacting concrete was first invited in 1988 to achieve durable concrete structures .Design of Reinforced concrete slab is often compromised by their ability to resist shear stress at punching shear surface area. The connection between slabs and supporting columns could be susceptible to high shear stress and might cause sudden and brittle failure. Punching shear failure takes the form of truncated pyramid shape. This program includes investigating the effect of SCC, slab thickness on the punching shear behaviour in terms of load-deflection response and ultimate failure load, failure characteristic of punching shear failure (shape of failure zone and size of failure zone) of simply supported slabs of 1000 x 1000 x 50 and 75mm under concentrated load at centre of slab. The slabs are made with both SCC and Conventional concrete (CC). Investigation included two way specimens with different thickness to evaluate the performance of specimen with different thickness and the effect of thickness on punching shear capacity and performance</em>.</p></div>

Analysis of seismic performance and research of load capacity of steel reinforced high strength concrete columns with rectangular helical hoops

2020 ◽  
pp. 136943322098165
Author(s):  
Jianyang Xue ◽  
Xin Zhang ◽  
Xiaojun Ke
Keyword(s):  
Failure Mode ◽  
Seismic Performance ◽  
Calculation Method ◽  
High Strength Concrete ◽  
Failure Modes ◽  
Shear Failure ◽  
High Strength ◽  
Shear Capacity ◽  
Strength Concrete ◽  
Shear Span

This paper mainly focused on the seismic performance and shear calculation method of steel reinforced high-strength concrete (SRHC) columns with rectangular helical hoops. An experimental investigation was performed in this paper. Eleven SRHC columns with rectangular helical hoops and one with ordinary hoops were constructed at the laboratory of Guangxi university. The failure modes, hysteresis loops, envelope curves, characteristic loads and displacements and cumulative damage analysis are presented and investigated. It can be seen from the test results that the failure modes of SRHC columns can be divided into three types with the shear span ratio increased, namely, shear baroclinic failure mode, flexure-shear failure mode and flexure failure mode. In addition, the specimens with rectangular helical hoops have plumper hysteretic loops. Shear span ratio is the main influencing factor of characteristic load; the axial compression ratio and concrete strength have less influence on characteristic load, while stirrup ratio has little effect on the characteristic load. Finally, a calculation method for shear capacity of SRHC columns under shear baroclinic failure and flexure-shear failure mode is proposed.

Compressive Strength and Splitting Tensile Strength of Steel Fiber Reinforced Ultra High Strength Concrete (SFRC)

2010 ◽  
Vol 34-35 ◽  
pp. 1441-1444 ◽  
Author(s):  
Ju Zhang ◽  
Chang Wang Yan ◽  
Jin Qing Jia
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Strength Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
High Strength ◽  
Splitting Tensile Strength ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Strength Concrete

This paper investigates the compressive strength and splitting tensile strength of ultra high strength concrete containing steel fiber. The steel fibers were added at the volume fractions of 0%, 0.5%, 0.75%, 1.0% and 1.5%. The compressive strength of the steel fiber reinforced ultra high strength concrete (SFRC) reached a maximum at 0.75% volume fraction, being a 15.5% improvement over the UHSC. The splitting tensile strength of the SFRC improved with increasing the volume fraction, achieving 91.9% improvements at 1.5% volume fraction. Strength models were established to predict the compressive and splitting tensile strengths of the SFRC. The models give predictions matching the measurements. Conclusions can be drawn that the marked brittleness with low tensile strength and strain capacities of ultra high strength concrete (UHSC) can be overcome by the addition of steel fibers.

Design of shear reinforcement for thick plates using a strut-and-tie model

2010 ◽  
Vol 37 (2) ◽  
pp. 181-194 ◽  
Author(s):  
H. Marzouk ◽  
E. Rizk ◽  
R. Tiller
Keyword(s):  
Shear Failure ◽  
Punching Shear ◽  
Shear Behaviour ◽  
Rational Approach ◽  
Concrete Slabs ◽  
Shear Reinforcement ◽  
Lower Section ◽  
Strut And Tie ◽  
Shear Cracking ◽  
Strut And Tie Model

The strut-and-tie method is a rational approach to structural concrete design that results in a uniform and consistent design philosophy. A strut-and-tie model has been developed to model the punching-shear behaviour of thick concrete plates. This model provides a quick and simple approach to check the punching-shear behaviour. Thick concrete slabs (250–500 mm) without shear reinforcement can exhibit brittle shear failure under a central force and an unbalanced moment. Shear reinforcement has proven to be very effective in preventing such failures. The developed strut-and-tie model has also been used to evaluate the minimum shear reinforcement required to prevent brittle shear failure of two-way slabs in the vicinity of concentrated loads. The strut-and-tie model for symmetric punching consists of a “bottle-shaped” compressive zone in the upper section of the slab depth, leading to a “rectangular-stress” compressive zone in the lower section of the slab depth. Inclined shear cracking develops in the bottle-shaped zone prior to failure in the lower zone. Cracking in the bottle-shaped zone is related to the splitting tensile strength of concrete.

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 Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)

2012 ◽  
Vol 2 (3) ◽  
Author(s):  
Farhad Aslani ◽  
Shami Nejadi
Keyword(s):  
Steel Fiber ◽  
Steel Reinforcement ◽  
Steel Fibers ◽  
Fiber Types ◽  
Reinforcing Steel ◽  
Structural Elements ◽  
Fiber Reinforced ◽  
Self Compacting Concrete ◽  
Inclined Angle ◽  
Bond Characteristics

AbstractSteel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths (τ (app)) and slip coefficient (β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle (ϕ). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers, information is hardly available in this area. In this study, bond characteristics of deformed reinforcing steel bars embedded in SFRSCC is investigated secondly.

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