TESTS OF ECCENTRICALLY COMPRESSED REINFORCED CONCRETE ELEMENTS STRENGTHENED BY CASES USING SELF-COMPACTING STEEL FIBER CONCRETE

The paper considers the effects of high temperatures in case of fire on the change in impermeability of steel fiber reinforced concrete having a high-strength cement-sand matrix and various content of fiber of different types, sizes, and strength. It is shown that in the temperature range from 20° to 1100° C in the diagram “Heating temperature - impermeability class», the matrix and steel fiber concrete(SFC) have a S-shaped character, and in case of heating temperature of over 100 °C, there comes a distinct decrease in impermeability.

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The Design Application of Steel Fiber Concrete on Bottom Frame Structure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.639-640.1241 ◽

2013 ◽

Vol 639-640 ◽

pp. 1241-1244

Author(s):

Jun Zuo

Keyword(s):

Reinforced Concrete ◽

Steel Fiber ◽

Internal Force ◽

Fiber Reinforced Concrete ◽

Frame Structure ◽

Steel Fiber Reinforced Concrete ◽

Concrete Frame ◽

Fiber Concrete ◽

Steel Fiber Concrete ◽

Bottom Frame

The concrete frame with bottom frame structure bear the load from the upper floors, roofing and brick walls, internal force is quite large, so the designed section size of frame beams is big, sometimes even the clear height of the building can't meet the architectural requirements; And more reinforcement, construction of concrete are difficult to pound, even vibration bar are difficult to insert into the beam, seriously influence the construction quality of reinforced concrete and the frame structure quality can't t be assured. This article introduces the design and application of steel fiber reinforced concrete in the bottom frame through the practical engineering examples. Steel fiber concrete can enhance the tensile and shear strength, and make it has good resistance to crack and toughness. As a result of the steel fiber concrete, the bearing capacity of bottom frame is greatly improved, and the problem in the project is solved.

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Reinforced concrete beams strengthened with steel fiber concrete

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/890/1/012045 ◽

2020 ◽

Vol 890 ◽

pp. 012045

Author(s):

Radaikin Oleg ◽

Sharafutdinov Linar

Keyword(s):

Reinforced Concrete ◽

Steel Fiber ◽

Concrete Beams ◽

Reinforced Concrete Beams ◽

Fiber Concrete ◽

Steel Fiber Concrete

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Research status and prospect of waste steel fiber reinforced concrete

E3S Web of Conferences ◽

10.1051/e3sconf/202124803039 ◽

2021 ◽

Vol 248 ◽

pp. 03039

Author(s):

Yu Binglin

Keyword(s):

Reinforced Concrete ◽

Steel Fiber ◽

Fiber Reinforced Concrete ◽

Synthetic Fiber ◽

Fiber Reinforced ◽

Steel Fiber Reinforced Concrete ◽

Scrap Tire ◽

Research Status ◽

Fiber Concrete ◽

Steel Fiber Concrete

Scrap steel fiber concrete (SFRC) is a new kind of concrete material, which uses the scrap steel fiber from the scrap tire as the reinforced fiber of FRP bar fiber reinforced concrete, replacing or partially replacing the traditional steel fiber and synthetic fiber. This paper summarizes the research status of waste steel fiber at home and abroad, including the mechanical properties of compressive and tensile resistance, the mixing amount and use requirements of waste steel fiber, and finally the development prospect of waste steel fiber concrete is forecasted

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Concrete grade change in the layers of three-layer steel fibre reinforced concrete beams

Journal of Achievements of Materials and Manufacturing Engineering ◽

10.5604/01.3001.0014.6325 ◽

2020 ◽

Vol 1 (102) ◽

pp. 16-29

Author(s):

T.Q.K. Lam ◽

T.M.D. Do ◽

V.T. Ngo ◽

T.T.N. Nguyen ◽

D.Q. Pham

Keyword(s):

Reinforced Concrete ◽

Steel Fiber ◽

Concrete Beams ◽

Vertical Displacement ◽

Reinforced Concrete Beams ◽

Stress Load ◽

Study Results ◽

Fiber Concrete ◽

Steel Fiber Concrete ◽

Layer Steel

Purpose: Determine the state of stress-strain, formation and development cracks, three-layer beam diagrams of load-compression stress, load-tension stress, load-vertical displacement relationships with a change in concrete grade. Design/methodology/approach: This paper presents the results of an ANSYS numerical simulation analysis involving stress-strain state and cracking of the steel fiber concrete layers of three-layer reinforced concrete beams with the upper and lower layers. With a cross-section of 150x300 mm, a total span of 2200 mm and an effective length of 2000 mm, the middle is a normal concrete layer. Under two-point loads, all the beam samples were tested. The research simulated three-layer concrete beams in different layers of beams with a change in concrete grade, and compared with and without the use of steel fibers in layers of concrete beams, including the nonlinearity of the material considered. Findings: A diagram of the formation and development of cracks in three-layer concrete beams has been constructed by the study results, determining the load at which the concrete beams begin to crack, the load at which the concrete beams are damaged. In the middle of three-layer steel fiber reinforced concrete beams, load-compression stress, loadtension stress, load-vertical displacement relationships are established. Study results show that these three-layer concrete beams appear to crack earlier than in other cases in cases 2 and 3, but the beam bearing capacity is damaged at 67 kN, the earliest in case 3. And case 6 at 116 kN is the latest. The effects of case 1 and case 3 are small compared with and without the use of steel fibers in cases, while the effects of case 5 and case 6 are very high. Research limitations/implications: The research focuses only on the change of concrete grade in the layers, but the input parameters affecting three-layer steel fiber concrete beams have not been researched, such as the number of tensile steel bars, tensile steel bar diameter, steel fiber content in concrete, thickness variation in three-layer concrete beam layers, etc. Practical implications: Provides a result of experimental study and ANSYS numerical simulation in multi-layer steel fiber concrete beams. Originality/value: The analysis of multi-layered steel fiber concrete beams using experimental and simulation methods shows that other parameters influencing the beams will continue to analysis the working stages of three-layer beams.

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Experimental Studies of Reinforced Concrete and Fiber-Reinforced Concrete Beams with Short-Term and Long-Term Loads

Materials Science Forum ◽

10.4028/www.scientific.net/msf.968.227 ◽

2019 ◽

Vol 968 ◽

pp. 227-233 ◽

Cited By ~ 1

Author(s):

Stepan Neutov ◽

Maryna Sydorchuk ◽

Mykola Surianinov

Keyword(s):

Reinforced Concrete ◽

Steel Fiber ◽

Concrete Beams ◽

Experimental Studies ◽

Fiber Reinforced Concrete ◽

Reinforced Concrete Beams ◽

Short Term ◽

Ordinary Concrete ◽

Fiber Concrete ◽

Steel Fiber Concrete

Experimental studies of the stress-strain state of reinforced concrete and fiber-reinforced concrete beams under short-term and long-term loads were carried out. The tests were carried out on three series of beams of different types - from ordinary concrete, steel fiber concrete and combined section, when the lower zone of the beam with a height of0.5his made of steel fiber concrete, and the upper one is made of ordinary concrete. During short-term loading, the load was applied in steps with a 10-minute exposure at each step to failure or to a predetermined level of a continuously acting load. In the interval between the steps, the process of cracking was tracked. After reaching a given level of loading, the load was fixed and maintained unchanged with a spring cassette for 300 days. Deformations were measured using strain gauges and dial gauges. Deflections and relative deformations of the extreme upper and extreme lower fibers for three types of beams are determined. It has been established that stabilization of deflections in beams from steel fiber concrete occurs much earlier (100 days) than in beams made of ordinary concrete (175 days). Studies have shown that the beams of ordinary concrete in the process of long-acting load lowered the carrying capacity by 5.5%. The bearing capacity of steel concrete beams, in contrast, increased by 7.6%.

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Study and Comparison of Characteristics of Models of Hollow-Core Slabs, Reinforced Concrete and Steel-Fiber Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.864.9 ◽

2020 ◽

Vol 864 ◽

pp. 9-18

Author(s):

Mykola Surianinov ◽

Stepan Neutov ◽

Iryna Korneieva ◽

Maryna Sydorchuk

Keyword(s):

Reinforced Concrete ◽

Steel Fiber ◽

Concrete Slab ◽

Fiber Reinforced Concrete ◽

Hollow Core ◽

Steel Fiber Reinforced Concrete ◽

Reinforced Concrete Slab ◽

Fiber Concrete ◽

Steel Fiber Concrete ◽

Correct Data

Two models of hollow core slabs were tested: reinforced concrete and steel fiber concrete. When designing slab models, the proportions of full-sized structures were preserved for the further possibility of correct data comparison. As a result of testing models of hollow core slabs, it was found that the bearing capacity of a slab with combined reinforcement is 24% higher than that of reinforced concrete, the deflection is 36% less, and the crack resistance is 18% higher. The use of steel fiber made it possible to avoid the brittle fracture of a steel fiber reinforced concrete slab, which was observed in the model of a conventional reinforced concrete slab.

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Numerical simulation of electric heating of dispersed-reinforced concrete with steel fibers

Journal of Physics Conference Series ◽

10.1088/1742-6596/2131/5/052064 ◽

2021 ◽

Vol 2131 (5) ◽

pp. 052064

Author(s):

E Matus ◽

M Soppa

Keyword(s):

Experimental Data ◽

Thermal Conductivity ◽

Reinforced Concrete ◽

Steel Fiber ◽

Electric Heating ◽

Contact Layer ◽

Concrete Mixture ◽

Study Results ◽

Fiber Concrete ◽

Steel Fiber Concrete

Abstract Solution to the problem of current density distribution in a fragment of a steel fiber concrete mixture is obtained, using the finite element method. It is shown that the fiber-concrete contact layer makes a significant contribution to the effective electrical conductivity of the mixture. More than 50% of the total current flows through the reinforcing fibers. The conductivity of the mixture increases in proportion to the reinforcement coefficient. It increases 2-3 times, depending on the choice of the contact properties, reinforcing 2% by volume layer. Experimental data that confirm the indicated dependence are presented. Also, a solution to the problem of heat distribution in a fragment of steel-fiber-concrete mixture in stationary and non-stationary modes of external heating and electrode heating was obtained. It is shown that the effective thermal conductivity coefficient increases in proportion to the reinforcement coefficient. A significant effect of the contact layer parameters on thermal conductivity is shown, comparison with experimental data. Significant heat release in the area of contact zone and in fiber leads to a temperature rise in these zones by 20-30 degrees in a stationary mode. The temperature distribution in fiber-reinforced concrete during induction heating is considered. In this case, it is necessary to significantly increase the frequency of the current used. The study results can be used, prescribing electric heating modes for products made of dispersion-reinforced concrete.

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EXPERIMENTAL STUDIES OF DEFORMABILITY AND FRACTURE RESISTANCE OF AIRFIELD SLABS ON MODELS

Mechanics And Mathematical Methods ◽

10.31650/2618-0650-2021-3-2-64-74 ◽

2021 ◽

Vol 3 (2) ◽

pp. 64-74

Author(s):

I. Korneieva ◽

◽

D. Kirichenko ◽

O. Shyliaiev ◽

◽

...

Keyword(s):

Reinforced Concrete ◽

Steel Fiber ◽

Concrete Slab ◽

Crack Opening ◽

Experimental Studies ◽

Measuring Instruments ◽

Reinforced Concrete Slab ◽

Fiber Concrete ◽

Steel Fiber Concrete ◽

Opening Width

The results of experimental studies of deformability and crack resistance of models of aerodrome slabs made of reinforced concrete and steel-fiber concrete, made on the basis of serial slab PAG-18 taking into account the scale factor, are presented. Two series of slabs were tested - two models of reinforced concrete and two models with one-percent dispersed reinforcement. The load was applied in steps, the instrument readings were recorded twice at each step and the crack opening width was measured starting from the moment of the first crack formation. Dial gauges, deflectometer and microscope MPB-3 were used as measuring instruments. In accordance with the normative documents acting in Ukraine, one of two possible loading schemes was considered - with the loading by the concentrated force applied in the span part of a plate which had a hinged support along its short sides. Plate models were tested on a specially made stand. Each load step ended with a five-minute dwell time, at the beginning and the end of which readings were taken on the measuring instruments. The deformations at the same levels were measured with dial gauges. The process of crack formation was observed with a Brinell tube in the places of the greatest crack opening. Breaking load for fiber concrete slab was 1.52 times higher than for reinforced concrete slab, and the moment of cracking initiation was 1.22 times higher. The process of cracking in the fiber concrete slab begins at higher loads than in the reinforced concrete slab. The initial crack opening width of the slabs is almost the same, and the final crack opening width of all the cracks in the fiber concrete slab is significantly lower than in the reinforced concrete slab. The deformations in steel-fiber concrete slabs when the load is applied in the span, both for compressed and stretched fibers, are higher than in reinforced concrete slabs. The experimental studies indicate that dispersed reinforcement of airfield slabs with steel fiber leads to their higher crack resistance.

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