scholarly journals Study on Adaptability of Test Methods for Workability of Fresh Self-Compacting SFRC

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5312
Author(s):  
Xinxin Ding ◽  
Haibin Geng ◽  
Kang Shi ◽  
Li Song ◽  
Shangyu Li ◽  
...  
Keyword(s):  
Steel Fiber ◽  
Volume Fraction ◽  
Test Methods ◽  
Fiber Reinforced Concrete ◽  
Ring Test ◽  
Steel Fiber Reinforced Concrete ◽  
Slump Flow ◽  
Filling Ability ◽  
Flow Test ◽  
Passing Ability

To ensure the quality of concrete construction, the workability of fresh mix measured by rational test methods is critical to be controlled. With the presence of steel fibers, whether the test methods and evaluation indices of fresh self-compacting concrete (SCC) are adaptable for self-compacting steel fiber reinforced concrete (SFRC) needs to be systematically verified. In this paper, seven groups of self-compacting SFRC, referenced with one group SCC, were prepared by using the mix proportion design method based on the steel fiber-aggregates skeleton packing test. The main factors included the volume fraction and the length of hooked-end steel fiber. Tests for filling ability, passing ability, and stability of fresh self-compacting SFRC and SCC were carried out. Results indicate that the adaptability was well for the slump-flow test with indices of slump flow and flow time T500 to evaluate the filling ability, the J-ring flow test with an index of PA level to evaluate the passing ability, and the static segregation test with an index of static segregation resistance to evaluate the stability of fresh self-compacting SFRC. By the repeated tests and measurements, the slump cone should be vertically lifted off to a height of 300 mm within 3 s at a constant speed, the spacing of the rebar in the J-ring test should be adjusted to be two times the fiber length. If the table jumping test is used, the dynamic segregation percent should be increased to 35% to fit the result of the static segregation test. Good workability of the self-compacting SFRC prepared in this study is presented with the general evaluation of test results.

Experiment Study on the Frost Resistance of Steel Fiber Reinforced Concrete on the Microstructure

2011 ◽  
Vol 368-373 ◽  
pp. 357-360
Author(s):  
Lei Jiang ◽  
Di Tao Niu ◽  
Min Bai
Keyword(s):  
Reinforced Concrete ◽  
Frost Resistance ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Nacl Solution ◽  
Steel Fiber Reinforced Concrete ◽  
Freeze Thaw ◽  
Damage Rate

Based on the fast freeze-thaw test in 3.5% NaCl solution, the frost resistance of steel fiber reinforced concrete (SFRC) was studied in this paper. On the basis of scanning electron microscope (SEM) and mercury intrusion method, the microstructure and pore structure of SFRC was analysed. The reinforced mechanism of SFRC under the cooperation of freeze-thaw and NaCl solution was discussed. The test results show that adding appropriate amount of steel fibers into concrete can reduce the pore porosity and improve the compactness of concrete. The effects of steel fiber with proper volume fraction can inhibit the peeling of the concrete and reduce its damage rate. The volume of steel fiber on the frost-resisting property of SFRC is obvious.

scholarly journals Shrinkage and Mechanical Properties of Self-Compacting SFRC With Calcium-Sulfoaluminate Expansive Agent

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 588 ◽  
Author(s):  
Changyong Li ◽  
Pengran Shang ◽  
Fenglan Li ◽  
Meng Feng ◽  
Shunbo Zhao
Keyword(s):  
Mechanical Properties ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Cementitious Materials ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Steel Fiber Reinforced Concrete ◽  
Volume Stability ◽  
Calcium Sulfoaluminate ◽  
Expansive Agent

With the premise of ensuring workability on a fresh mixture, the volume stability of hardened self-compacting steel fiber reinforced concrete (SFRC) becomes an issue due to the content of cementitious materials increased with the volume fraction of steel fiber. By using the expansive agent to reduce the shrinkage deformation of self-compacting SFRC, the strength reduction of hardened self-compacting SFRC is another issue. To solve these issues, this paper performed an experimental investigation on the workability, shrinkage, and mechanical properties of self-compacting SFRC compared to the self-compacting concrete (SCC) with or without an expansive agent. The calcium-sulfoaluminate expansive agent with content optimized to be 10% mass of binders and the steel fiber with a varying volume fraction from 0.4% to 1.2% were selected as the main parameters. The mix proportion of self-compacting SFRC with expansive agent was designed by the direct absolute volume method, of which the steel fibers are considered to be the distributed coarse aggregates. Results showed that rational high filling and passing ability of fresh self-compacting SFRC was ensured by increasing the binder to coarse-aggregate ratio and the sand ratio in the mix proportions; the autogenous and drying shrinkages of hardened self-compacting SFRC reduced by 22.2% to 3.2% and by 18.5% to 7.3% compared to those of the SCC without expansive agent at a curing age of 180 d, although the expansion effect of expansive agent decreased with the increasing volume fraction of steel fiber; the mechanical properties, including the compressive strength, the splitting tensile strength, and the modulus of elasticity increased with the incorporation of an expansive agent and steel fibers, which met the design requirements.

scholarly journals Behavior of Rectangular-Sectional Steel Tubular Columns Filled with High-Strength Steel Fiber Reinforced Concrete Under Axial Compression

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2716 ◽  
Author(s):  
Shiming Liu ◽  
Xinxin Ding ◽  
Xiaoke Li ◽  
Yongjian Liu ◽  
Shunbo Zhao
Keyword(s):  
Energy Dissipation ◽  
Bearing Capacity ◽  
Failure Modes ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Local Buckling ◽  
Steel Tube ◽  
Fiber Reinforced Concrete ◽  
Steel Fiber Reinforced Concrete ◽  
Energy Dissipation Capacity

This paper studies the effect of high-strength steel fiber reinforced concrete (SFRC) on the axial compression behavior of rectangular-sectional SFRC-filled steel tube columns. The purpose is to improve the integrated bearing capacity of these composite columns. Nine rectangular-sectional SFRC-filled steel tube columns and one normal concrete-filled steel tube column were designed and tested under axial loading to failure. The compressive strength of concrete, the volume fraction of steel fiber, the type of internal longitudinal stiffener and the spacing of circular holes in perfobond rib were considered as the main parameters. The failure modes, axial load-deformation curves, energy dissipation capacity, axial bearing capacity, and ductility index are presented. The results identified that steel fiber delayed the local buckling of steel tube and increased the ductility and energy dissipation capacity of the columns when the volume fraction of steel fiber was not less than 0.8%. The longitudinal internal stiffening ribs and their type changed the failure modes of the local buckling of steel tube, and perfobond ribs increased the ductility and energy dissipation capacity to some degree. The compressive strength of SFRC failed to change the failure modes, but had a significant impact on the energy dissipation capacity, bearing capacity, and ductility. The predictive formulas for the bearing capacity and ductility index of rectangular-sectional SFRC-filled steel tube columns are proposed to be used in engineering practice.

scholarly journals Using Steel Fiber-Reinforced Concrete Precast Panels for Strengthening in Shear of Beams: An Experimental and Analytical Investigation

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Pitcha Jongvivatsakul ◽  
Linh V. H. Bui ◽  
Theethawachr Koyekaewphring ◽  
Atichon Kunawisarut ◽  
Narawit Hemstapat ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Experimental Program ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume ◽  
Simple Formulation

In this paper, the performances of reinforced concrete (RC) beams strengthened in shear with steel fiber-reinforced concrete (SFRC) panels are investigated through experiment, analytical computation, and numerical analysis. An experimental program of RC beams strengthened by using SFRC panels, which were attached to both sides of the beams, is carried out to investigate the effects of fiber volume fraction, connection type, and number and diameter of bolts on the structural responses of the retrofitted beams. The current shear resisting model is also employed to discuss the test data considering shear contribution of SFRC panels. The experimental results indicate that the shear effectiveness of the beams strengthened by using SFRC panels is significantly improved. A three-dimensional (3D) nonlinear finite element (FE) analysis adopting ABAQUS is also conducted to simulate the beams strengthened in shear with SFRC panels. The investigation reveals the good agreement between the experimental and analytical results in terms of the mechanical behaviors. To complement the analytical study, a parametric study is performed to further evaluate the influences of panel thickness, compressive strength of SFRC, and bolt pattern on the performances of the beams. Based on the numerical and experimental analysis, a shear resisting model incorporating the simple formulation of average tensile strength perpendicular to the diagonal crack of the strengthened SFRC panels is proposed with the acceptable accuracy for predicting the shear contribution of the SFRC system under various effects.

Influence of Fiber Volume Fraction and Aggregate Size on Flexural Behavior of High Strength Steel Fiber-Reinforced Concrete (SFRC)

2013 ◽  
Vol 372 ◽  
pp. 223-226 ◽  
Author(s):  
Seok Joon Jang ◽  
Yeon Jun Yun ◽  
Hyun Do Yun
Keyword(s):  
Reinforced Concrete ◽  
Fiber Volume Fraction ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Aggregate Size ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Flexural Behavior ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume

The effects of aggregate size and fiber volume fraction on the flexural behavior of 70MPa high strength steel fiber-reinforced concrete (SFRC) were investigated in this work. Test variables consist of fiber volume fraction (0, 1 and 2 %) and maximum aggregate size (8, 13 and 20 mm). The prism for flexural test was 100 x 100 x 400 mm and was tested under four points loading. Flexural toughness index was measured using ASTM C 1018 procedure. Test results indicated that the addition of steel fiber to 70MPa high strength concrete improves flexural and post-cracking behaviors. This phenomenon is remarkable for SFRC mixture with higher fiber content and smaller aggregate size. Also, the flexural toughness of high strength SFRC depends primarily on fiber content. The maximum aggregate sizes were secondary in importance.

scholarly journals Statistical Analysis and Preliminary Study on the Mix Proportion Design of Self-Compacting Steel Fiber Reinforced Concrete

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 637 ◽  
Author(s):  
Xinxin Ding ◽  
Minglei Zhao ◽  
Siyi Zhou ◽  
Yan Fu ◽  
Changyong Li
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Calculation Model ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Mix Proportion ◽  
Binder Ratio ◽  
Water To Binder Ratio

With the sustainable development of green construction materials in civil engineering, self-compacting steel fiber reinforced concrete (SC-SFRC) has attracted widespread attention due to its superior self-compacting performance and excellent hardened properties. In this paper, 301 groups of test data from published literatures were collected to quantify the characteristics of the mix proportion of SC-SFRC. The type, aspect ratio and volume fraction of steel fiber commonly used in SC-SFRC are discussed and the effects of steel fiber on the workability and mechanical properties of SC-SFRC are statistically studied. The relationship of cubic compressive strength and water-to-binder ratio and that of the splitting tensile strengths between SC-SFRC and referenced self-compacting concrete (SCC) are also evaluated. Based on these analyses, the reasonable ranges of material components in the mix proportion design of SC-SFRC are determined. The results showed that with several adjusted parameters, the calculation model of the water-to-binder ratio for the mix proportion design of ordinary concrete is suitable for SC-SFRC. The calculation model of tensile strength is suggested for SC-SFRC with various types of steel fiber.

Seismic Performance of SFRC Piers under Reversed Cyclic Loading

2012 ◽  
Vol 178-181 ◽  
pp. 2228-2235 ◽  
Author(s):  
Yu Ye Zhang ◽  
Hong Yi Wei ◽  
Wan Cheng Yuan ◽  
Wei Hu
Keyword(s):  
Energy Dissipation ◽  
Bearing Capacity ◽  
Seismic Behavior ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Plastic Hinge ◽  
Content Volume ◽  
Fiber Reinforced Concrete ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume

Steel fiber reinforced concrete (SFRC) has many good dynamic performances such as toughness and ductility. However, few studies have focused on SFRC’s application in bearing member of bridge structures. In this paper, pseudo-static cyclic tests of eight pier specimens are carried out to investigate seismic behavior of piers using SFRC. The main variables in the testing are the steel fiber content (volume fraction of 0.0%, 0.5%, 1.0% and 1.5%), the length of SFRC region and the stirrup ratio of piers. Seismic behavior of the test specimens, like the failure pattern, the hysteretic characteristics, the skeleton curves, the ductility and the energy dissipation are investigated experimentally. The results show that, 1) the SFRC pier with the steel fiber volume fraction of 1.0% has much better performance than that with other fiber volume contents, particularly for bearing capacity, hysteretic energy dissipation and ductility; 2) the pier specimen can keep sufficient seismic capacity, in which some stirrups are replaced by steel fibers; and 3) compared with specimen with application of SFRC in entire pier, the specimen with appropriate local application of SFRC in potential plastic hinge region can sustain almost the same seismic properties, such as the ultimate bearing capacity, the stiffness, the ductility and the energy dissipation capacity.

scholarly journals Performance of Hybrid Steel Fibers Reinforced Concrete Subjected to Air Blast Loading

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mohammed Alias Yusof ◽  
Norazman Mohamad Nor ◽  
Ariffin Ismail ◽  
Ng Choy Peng ◽  
Risby Mohd Sohaimi ◽  
...  
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Blast Loading ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Air Blast ◽  
Air Blast Loading

This paper presents the results of the experimental data and simulation on the performance of hybrid steel fiber reinforced concrete (HSFRC) and also normal reinforced concrete (NRC) subjected to air blast loading. HSFRC concrete mix consists of a combination of 70% long steel hook end fibre and also 30% of short steel hook end fibre with a volume fraction of 1.5% mix. A total of six concrete panels were subjected to air blast using plastic explosive (PE4) weighing 1 kg each at standoff distance of 0.3 meter. The parameters measured are mode of failure under static and blast loading and also peak overpressure that resulted from detonation using high speed data acquisition system. In addition to this simulation work using AUTODYN was carried out and validated using experimental data. The experimental results indicate that hybrid steel fiber reinforced concrete panel (HSFRC) possesses excellent resistance to air blast loading as compared to normal reinforced concrete (NRC) panel. The simulation results were also found to be close with experimental data. Therefore the results have been validated using experimental data.

Experiment Study on the Frost Resistance of Steel Fiber Reinforced Concrete

2010 ◽  
Vol 150-151 ◽  
pp. 243-246 ◽  
Author(s):  
Lei Jiang ◽  
Di Tao Niu ◽  
Min Bai
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Early Stage ◽  
Variable Parameter ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Freeze Thaw ◽  
Splitting Strength

In order to study various factor affecting durability of steel fiber reinforced concrete (SFRC), basic experimental research that combine the action of freezing-thawing cycles and deicing salt to SFRC was conducted. In the experiment, the volume fraction of steel fiber and number of freeze-thaw circulation are taken as variable parameter. Based on the different numbers of freeze-thaw circulation, weight losing of SFRC, splitting strength and the dynamic modulus of elasticity were measured. Furthermore, the reinforced mechanism of the SFRC under the action of freeze-thaw was analysed. The test results show that after adding a certain amount of steel fiber to the concrete, cracks in concrete at early stage are effectively prevented and the permeability of concrete is obviously reduced, thus the durability of concrete is improved. The reinforced actions of steel fiber on splitting strength of concrete are notable and the influence of steel fiber volume fraction on the frost-resisting property is obvious. On the contrary, the negative effects of steel fiber with high volume fraction on the splitting strength of concrete exist. The best performance of SFRC can be got when the steel fiber quantity is 1.5%.

Shrinkage Performance of Adherence of New Steel Fiber-Reinforced Concrete to Old Concrete

2010 ◽  
Vol 163-167 ◽  
pp. 3569-3574
Author(s):  
Hong Qiang Cheng ◽  
Dan Ying Gao
Keyword(s):  
Reinforced Concrete ◽  
Fiber Volume Fraction ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume ◽  
Shrinkage Force ◽  
The Difference

Shrinkage experiments were done to determine the influence of the volume fraction of steel fiber-reinforcement on the bonding behavior between new concrete and old concrete. The mechanics of the model of restricted shrinkage upon the adherence of new steel fiber reinforced concrete to old concrete are described. The results demonstrate that the difference of shrinkage between the new and the old concrete can been reduced by adding steel fiber to the new concrete. The decrease of shrinkage difference reduces the shrinkage force at the adhesive interface, which improves the adhesion of new concrete to old concrete and the magnitude of the decrease of shrinkage difference is correlated to the steel fiber volume fraction.

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