Steel Fiber Content Research Articles

Compressive constitutive behavior of steel fiber reinforced geopolymeric recycled aggregate concrete: Experimental investigation and analytical model

With the incorporation of industrial wastes and recycled concrete aggregate (RA), steel fiber reinforced geopolymeric recycled aggregate concrete (SFR-GRAC) can ensure both high performance and environmental benefits simultaneously. As a green concrete, SFR-GRAC is promising for practical engineering applications and its constitutive behavior needs a systematical study. This paper presented an experimental investigation on the stress–strain behavior of SFR-GRAC under uniaxial compression, focusing on the effect of RA substitute rates (25%, 50%, 75% and 100%) and steel fiber (SF) volume fractions (0.5%, 1.0% and 1.5%). The failure pattern, compressive strengths, stress–strain curve and corresponding characteristics, as well as energy absorption capacity were studied. The results show that the addition of SF improves the failure pattern and specimen integrity, as well as the mechanical properties in terms of peak stress, peak strain, elastic modulus and toughness due to the fiber crack-bridging action. The compressive strength and elastic modulus of GRAC are deteriorated with the use of RA, except that the decreases are less pronounced when the RA contents are below 50%. Moreover, the negative impact induced by the inclusion of RA can be alleviated by the addition of SF and the activation of alkali-activator as the rehydration of cement particles in old pastes in RA. Finally, based on a comprehensive analysis of the test results in current study and literature, empirical constitutive relations are established to model the stress–strain responses of SFR-GRAC with various RA and SF contents under axial compression, and model predictions show close agreements with test results.

Effect of steel fiber on the permeability of freeze-thaw damaged concrete under splitting tensile and compressive loads

This study investigated the effect of steel fibers on the permeability and mechanical properties of freeze-thaw damaged concrete under splitting tensile and compressive loads. A specially designed permeability apparatus is used to investigate the continuous permeability performance of steel fiber reinforced concrete (SFRC) subjected to loads. Results demonstrated that for the concrete without load, the addition of steel fibers exhibits a negative effect on the impermeability performance of the concrete matrix without freeze-thaw damage. The initial permeability of SFRC specimens is between 81.7 % and 180 % higher than that of NC specimens. The addition of steel fibers shows a positive effect on the impermeability of concrete subjected to freeze-thaw cycles. The permeability of SFRC under loads can be categorized into two stages. In the first stage, the concrete matrix is the main water channel. The addition of steel fiber can effectively increase the maximum radial deformation of the first stage and maintain low permeability of concrete in a large radial deformation range. In the second stage, concrete cracks are the main water channels. Both the addition of steel fibers and freeze-thaw cycles can reduce the permeability of the concrete in the second stage. Furthermore, under compressive load, with the increasing of stress level, the permeability of SFRC exhibits a slowly decreasing trend, this is followed by a significant increasing trend. The addition of steel fibers can maintain low permeability performance in a large stress level range, and as the steel fiber content increases, the permeability at peak load gradually decreases. The strain–permeability curves of SFRC under splitting tensile and compressive loads subjected to freeze-thaw cycles are investigated. The permeability of SFRC gradually increases with the increasing of the number of freeze-thaw cycles when the compressive strain exceeds 0.002. However, the opposite trend is observed under splitting tensile load. Notably, the reduction in concrete permeability due to the steel fibers is more significant under splitting tensile load than that under compressive load. Future work might integrate this research with stress-strain constitutive equations and finite element analysis. This will offer a foundational framework for engineering applications aimed at enhancing the permeability of steel fiber concrete under freeze-thaw conditions.

Study on mechanical properties and microstructure of steel-polypropylene fiber coal gangue concrete

Incorporating coal gangue into the concrete matrix can realize the utilization of solid waste and reduce the use of natural aggregate. To improve the mechanical properties of coal gangue concrete, this paper designs four-level and four-factor orthogonal tests with coal gangue ceramide substitution rate, coal gangue ceramide sand substitution rate, steel fiber content, and polypropylene fiber content as independent variables. Through multidimensional data analysis of the test results, The main and secondary factors of compressive strength of hybrid fiber coal gangue concrete from strong to weak are the replacement rate of coal gangue ceramic sand, the replacement rate of coal gangue ceramic grain, the content of steel fiber and the content of polypropylene fiber. The optimal content is 30% coal gangue ceramic particle, 25∼30% coal gangue ceramic sand, 0.75∼1% steel fiber, and 0.2% polypropylene fiber. The grey prediction model GM (1, 5) is obtained, which can predict the concrete strength well within the range selected in this paper. The influence of fiber and coal gangue on the microstructure was studied by scanning electron microscopy, and the influence law of interfacial transition zone on the strength of concrete was explored, which provided a theoretical basis for the study of solid waste utilization of coal gangue.

Influence of Type and Volume Content of Steel Fiber on the Compressive Strength of Ultra-High Performance Fiber Reinforced Concrete

The paper presents the results of determining the compressive strength of various compositions of Ultra-High Performance Fiber Reinforced concrete (UHPFRC) with fiber volume content from 1 to 3%. Four types of fibers were used: corrugated fiber of 15/0.3 mm and 22/0.3 mm, straight fiber of 13/0.3 mm and hooked-end fiber of 30/0.5 mm. It was found that corrugated and hooked-end fiber leads to an increase in compressive strength by 10–30 MPa when its content is increased from 1 to 3%. Straight fiber has no noticeable effect on the mechanical properties of UHPFRC. Empirical equations for predicting the compressive strength of UHPFRC depending on the strength of concrete matrix, geometric dimensions and content of dispersed reinforcement for compositions with corrugated and hooked-end fibers have been obtained. It is found that increasing the volume content of aggregate in the concrete matrix composition from 0.2 to 0.4 m3/m3 leads to an increase in the strength of UHPFRC. The strength of specimens with corrugated fiber increased by 5.3–13.3 MPa, with hooked-end fiber – by 14–19.3 MPa, with straight fiber – 5–7 MPa. It is also noted that the most intensive growth of mechanical characteristics due to the increase in the aggregate volume content in the composition is observed at a higher percentage of fiber volume fraction.

Structural Performance of Ferrocement Panels under Low- and High-Velocity Impact Load.

The primary objective of this experimental study is to examine the response and energy absorption capacity of ferrocement panels exposed to low- and high-velocity impact loads. The panels are reinforced with two different types of mesh layers, namely, welded wire grid (WWG) and expanded wire grid (EWG), with varying percentages of steel fibers (SF). The ferrocement panel system is made up of cement mortar reinforced with 0-2% SF with an increment of 1% and wire grid layers arranged in three different layers 1, 2, and 3. A consistent water-cement ratio (w/c) of 0.4 is maintained during mortar preparation, and all panels are subjected to a 28-day curing process in water. The study utilized square-shaped ferrocement panels measuring 290 mm × 290 mm × 50 mm. The panels are exposed to repeated impact blows from a 2.5 kg falling mass dropped from a height of 0.80 m. The count of blows necessary to commence the first crack formation and the cause of ultimate failure are recorded for each panel. The study reports that an increase in SF content and the number of wire grid layers increased the number of blows needed for both the first crack and the ultimate failure. In the high-velocity impact test, 7.62 mm bullets are fired at the panels from a distance of 10 m with a striking velocity of 715 m/s. The study observed and analyzed the extent of spalling, scabbing, and perforation. The results showed that an increase in fiber content and the number of wire grid layers led to a decrease in the area of scabbing and spalling compared with the control specimens. It was also possible to see the mode of failure and crack pattern for impacts with low and high velocities.

Experimental and numerical analyses of the effect of fibre content on the close-in blast performance of a UHPFRC beam

Limited research has been conducted on the influences of fiber content on close-in blasting characteristics for ultrahigh-performance fiber-reinforced concrete (UHPFRC) beams. This paper aims to address this knowledge gap through experimental and mesoscale numerical methods. Experiments were conducted on ten UHPFRC beams built with varying steel fiber volumetric fractions subjected to close-in explosive conditions. Additionally, this study considered other parameters, such as the longitudinal reinforcement type and ratio. In the case of UHPFRC beams featuring normal-strength longitudinal reinforcement of diameters Φ12, Φ16, and Φ20, a reduction in maximum displacement by magnitudes of 19.6%, 19.5%, and 17.4% was observed, respectively, as the volumetric fractions of fiber increased from 1.0% to 2.5%. In addition, increasing the longitudinal reinforcement ratio and using high-strength steel longitudinal reinforcement both significantly reduced the deformation characteristics and increase the blasting resistances of UHPFRC beams. However, the effects on the local crushing and spalling damage were not significant. A mesoscale finite element model, which considers the impacts of fiber parameters on UHPFRC beam behaviors, was also established and well correlated with the test findings. Nevertheless, parametric analyses were further conducted to examine the impacts of the steel fiber content and length and the hybrid effects of various types of microfibers and steel fibers on the blasting performance of UHPFRC beams.

Influences on the mechanical and physical properties of hot-press moulding alkali-activated slag (HP-FRAASC) composite with various fibers

ABSTRACT In this study, we will apply the hot-press moulding method for the first time to the preparation of alkali-activated slag composites (AASC) and incorporate 1vol.-%, 3vol.-%, 5vol.-%, and 7vol.-% steel, copper, and carbon fibres into the matrix in order to investigate the characteristics of the HP-AASC and fibre reinforced (HP-FRAASC) in terms of compressive strength, flexural strength, impact toughness, and bulk density of HP-AASC and HP-FRAASC. Results show that the composites have good flexural strength, compressive strength, and impact toughness when the content of steel fibres is 5 vol.-%, copper fibres are 7 vol.-%, and carbon fibres are 1–3 vol.-%. It was observed from each sample of HP-FRAASC and HP-AASC that the HP-AASC samples had lower porosity, better density, and an easy preparation process, which can be used as a suitable preparation method for this material.

The Influence of UHPFRC Jacket Steel Fiber Content on Strengthening Damaged Columns

Steel fiber is a commonly used material to repair damaged concrete, caused by environmental or design issues. This study used various Micro-copper-coated Steel Fiber (MSF) content (0.0, 0.5, 2.0, and 2.5%) with varying aspect ratios (28, 37, and 45) as part of Ultra-High-Performance Fiber-Reinforced Concrete (UHPFRC) mixtures to repair damaged concrete columns using a 30 mm layer jacketing. Twelve columns were prepared and tested at first by loading them with roughly 90% of their ultimate axial load capacity. Damage was caused and the columns were subsequently strengthened and rebuilt using UHPFRC mixtures in 30-mm layer jacketing for a second test, to determine the effect of UHPFRC and MSF content on damaged and reinforced columns. The test results showed that the concrete properties improved as the MSF content increased to 2.0% of the volume fraction, beyond which there was a slight reduction. Additionally, the UHPFRC-strengthened columns with and without MSFs experienced higher load capacities than the corresponding unstrengthened. On the contrary, using 2.5% MSF in the UHPFRC decreased the loading capacity by 14% compared to the UHPFRC with 2.0% MSF. The strengthened column with 2.0% MSF content showed the highest load efficiency (165.7% compared to unstrengthened), along with substantial displacement and ductility.

Tensile behavior and failure modes of expansion anchors in High-Performance Steel Fiber Reinforced Concrete (HPSFRC)

To investigate the tensile(pullout) behavior of expansion anchors in High-Performance Steel Fiber Reinforced Concrete(HPSFRC), 30 valid unconfined tension(pullout) tests on expansion anchors, studying the effects of different steel fiber content(0.0 %, 0.5 %, 1.0 %, and 1.5 %), embedment depths(25 mm, 35 mm, and 45 mm), and anchor diameters(10 mm and 12 mm) on the tensile behavior of anchors. A total of seven failure modes, including different types of mixed modes, are observed. The incorporation of fibers reduces the anchorage stiffness, increases the ductility, and improves the post-peak performance of the tensile behavior of anchors. Effective embedment depth(Hef)exerts a great influence on the failure mode; as Hef increases, the dominant failure mode transits from the concrete breakout to the pull-through and mixed failure modes, and finally the steel failure mode. The increase in Hef also leads to increases in the ultimate tensile strength of the anchor(Nu) and the anchorage ductile. For the same Hef and fiber content, compared to the smaller diameter(D), Nu for the larger diameter is larger but the pullout ductility is weaker. A modified model considering the influence of steel fibers is proposed to predict Nu of CB mode in HPSFRC, and it results in more accurate predictions compared to the existing prediction models(CCD model, Toth model). An existing prediction model for PT mode in normal concrete has been proven to be applicable for anchors HPC/HPSFRC.

Push-out tests of interfacial bond slip between H-shaped steel and ultra-high performance concrete

The effects of steel fiber content, stirrup reinforcement ratio, cover thickness of ultra-high performance concrete (UHPC) and embedded length of H-shaped steel on interfacial bond performance were studied through pull-out tests of ten specimens. The crack development process and damage mode of the specimens were analyzed by the load-slip(P-S) curves obtained at the loading end and the strain distribution of the H-shaped steel web. A formula for characteristic bond strength of H-shaped steel and UHPC was established, and a constitutive relationship for bond slip was proposed. A finite element model based on nonlinear springs was established to simulate the bond-slip relationship and the whole process of loss of performance at the interface of H-shaped steel and UHPC. The results showed that the strain of H-shaped steel decreased gradually along its embedment length, and the amount of steel fiber content, cover thickness and embedding length had large influences on the ultimate bond stress.

Evaluation of Flexural Toughness of Concrete Reinforced with High-Performance Steel Fiber.

In this study, a flexural test and residual stress evaluation using the aspect ratio (65 and 80) and steel fiber content (20, 30, and 40 kg/m3) as variables were conducted according to the EN 14651 standard to investigate the flexural toughness of concrete reinforced with high-performance arched steel fibers. The result of the flexural test show that the residual stress was 114.5% higher in the test specimen with high curvature and high content of arched steel fibers than that in the other conditions. In addition, the energy absorption capacity of arched steel fiber-reinforced concrete increased by 138.88% compared to concrete.

Statistics of acoustic emission waveforms in characterizing the fracture process zone in fibre-reinforced cementitious materials under mode I fracture

This article reports on the characteristics of fracture process zone in steel fibre-reinforced concrete (SFRC) under the mode I fracture process using acoustic emission (AE) testing. The generated AE waveforms during mode I fracture process in SFRC were recorded in the laboratory. Using a statistical analysis of AE waveforms, it was observed that as the loading increases, a damage zone consisting of numerous microcracks develops ahead of the predefined notch tip. The location of the generated AE events related to the numerous microcracks were classified into three zones namely (i) major damage, (ii) moderate damage and (iii) low damage. The areas of these regions were evaluated from the distribution of the AE events around the pre-notch. The number of AE events reduced with the increase in the steel fibre content under the same experimental conditions. The major damage zone was located ahead of the notch tip very closely and it comprised of AE events with (i) high peak amplitude, (ii) low information entropy and (iii) longer AE waveform duration.

Study on the Dynamic Mechanical Properties of Ultrahigh-Performance Concrete under Triaxial Constraints.

To confirm the effect of confining pressure on the dynamic mechanical behavior of ultrahigh-performance concrete (UHPC), this study used a true triaxial split Hopkinson pressure bar test system to perform dynamic compression tests on UHPC under triaxial constraints. The confining pressure range considered was 5~10 MPa, the strain rate range was 35~80 s-1, and the steel fiber contents were 0.5%, 1% and 2%. The three-dimensional dynamic engineering stress-strain relationship and equivalent stress-strain relationship of UHPC under different confining pressures and different strain rates were obtained and analyzed in detail. The results show that under the confinement condition, the dynamic peak axial stress-strain and dynamic peak lateral stress-strain of UHPC have strong sensitivity to the strain rate. In addition, the dynamic peak lateral stress-strain is more sensitive to the confining pressure than the dynamic axial stress. An empirical strength enhancement factor (DIFc) that considers the strain rate effect and confining pressure was derived, and the impact of the coupling between the enhancement caused by the confining pressure and the strain rate effect on the dynamic strength of the UHPC under triaxial confinement was discussed. A dynamic strength failure criterion for UHPC under triaxial constraint conditions was established.

Study on the impact resistance of steel fiber-reinforced self-compacting concrete after high temperature

The present study explored the dynamic mechanical properties of steel fiber-reinforced self-compacting concrete (SFRSCC) after a high temperature. The impact test was conducted using a φ80 mm split Hopkinson pressure bar (SHPB) device, with a focus on the factors of influence and the regularity of steel fiber content (0.5 %, 1.0 %, and 1.5 %), impact strain rate (55 s−1, 90 s−1, and 140 s−1), and temperature (20 °C, 300 °C, 600 °C, and 900 °C) on the failure form, dynamic strength, impact toughness, and dynamic increase factor (DIF-σ) of SFRSCC after high-temperature exposure, and the mechanism analysis based on the results of the SEM examination. The impact test results revealed the following: (1) With the increase in the steel fiber (SF) content, the dynamic strength (fp) of the SFRSCC exhibited a further evident growth trend after high temperature compared to that at normal temperature reaching 105 % and the toughness index also increased by more than 20 %. (2) While the effect of SF content on DIF-σ of SFRSCC was not significant under normal temperature conditions after high-temperature exposure, the DIF of SFRSCC can increase by over 40 % with the increase of SF content. In addition, the strain rate effect was also further significant, and the DIF-σ can increased by about 30 % after high-temperature treatment compared to normal temperature. (3) A prediction formula was proposed for DIF-σ of SFRSCC after high temperature, and the results were in good agreement with the results of the impact test. This prediction formula can better provide theoretical data support for disaster prevention and reduction in subsequent projects. The findings of the present study would serve as a valuable reference for subsequent research on the impact resistance of SFRSCC after high-temperature exposure.

Compression and bending of alkali-activated slag cementitious materials at high temperature

Alkali-activated slag cementitious material (AASCM) with manufactured sand can effectively utilise industrial waste slag and reduce river sand consumption. Steel fibres can effectively improve the mechanical properties of AASCM. Therefore, in this study, the influence of steel fibres and aggregate type on the compression and bending properties of AASCM after high-temperature treatment was investigated. The results show that the mass loss rate, compressive strength and flexural strength loss rate of AASCM with manufactured sand were higher than those with natural river sand at different temperatures. Steel fibres can increase the mass loss rate of AASCM; however, the influence of the steel fibre content on the mass loss of AASCM was not apparent. When the temperature was lower than 600°C, the compressive and flexural strength of AASCM was effectively increased by steel fibres, while, for temperatures higher than 800°C, the mechanical properties of AASCM did not improve, owing to the oxidation failure of steel fibres. Microstructure analysis showed that the number of microcracks in the AASCM increased, owing to the high silicon content of the manufactured sand, and the bond property between the steel fibres and cementitious materials decreased with an increase in temperature.

Induction Heating and Cooling Performance of Asphalt Mixture as Recycling Rap and Steel Slag

Recycling reclaimed asphalt pavement (RAP) for asphalt pavement construction is of interest due to its potential to mitigate environmental impact and resource consumption; however, the addition of RAP limits the induction heating behavior of asphalt mixtures, hindering the further application of RAP in sustainable and functional asphalt pavement. This study prepared recycled asphalt mixtures with high contents of steel slag aggregate and RAP, and optimized the rejuvenator dosage and composition design to investigate the induction heating rate. The effect of the steel fiber content, heating time, and heating distance on the induction capacity were verified for the recycled asphalt mixture. Moreover, the cooling curves of the recycled asphalt mixture were explored using a constant temperature chamber and infrared camera. The results showed that 6 wt% of rejuvenator in aged asphalt could evidently restore the physical properties and surface morphology, the highest heating rate of 1.204 °C/s could be reached with 2 wt% of steel fiber content, and the effective intervals of heating time and heating distance were set as 60–120 s and 10–20 mm, respectively. This study could be a significant reference in promoting solid waste recycling and sustainable asphalt pavement construction.

Investigating compressive strength of concrete containing steel fiber by data-driven approach

The main objective of this paper is to use the data-driven approach to predict and study the factors affecting the compressive strength of steel fiber concrete. Therefore, six machine learning (ML) models were evaluated against a database of 166 samples and ten input variables, including Cement content, Water content, Silica fume content, Steel fiber content, Coarse aggregate content, Sand content, Superplasticizer content, Fiber diameter, Fiber length, Fly ash content. SixMLmodels, including Artificial Neural Network (ANN), K-Nearest Neighbor (KNN), Categorical Boosting (CatB), Random Forest (RF), Gradient Boosting (GB), and Extreme Gradient Boosting (XGB), are evaluated against performance metrics and validated by 1000 Monte Carlo simulations. The compressive strength prediction performance by the ML models is arranged in descending order as follows XGB>GB>CatB>RF >ANN>KNN. The two best models can predict the compressive strength of steel fiber concrete to be GB with a coefficient of determination (R2) of 0.9874 and a root mean square error (RMSE) of 2.5763 MPa and XGB with an R2 of 0.9926 and an RMSE of 1.9814 MPa for the testing dataset. The influence of the ten variables can be arranged in descending order as follows: Cement content > Water content > Silica fume content > Steel fiber content >Coarse aggregate content > Sand content > Superplasticizer content > Fiber diameter > Fiber length > Fly ash content. Among them, Cement content, Silica fume content, and Steel fiber content have a positive effect on improving the compressive strength of concrete. The steel fiber content used should be less than 1.5% of concrete volume to improve the efficiency of steel fiber in concrete. Meanwhile, Fiber diameter and Fiber length have a minimal influence on the compressive strength of steel fiber concrete.

Bearing behavior of steel fiber reinforced recycled aggregate concrete blocks

The bearing strength of concrete is considered as essential design parameter for safely transmitting load to concrete supports, including support anchorage, post-tension member, corbel, bridge pedestal, column-foundation, and other forms of superstructure supports. End-hooked steel fiber has never previously been used to improve the bearing strength of recycled aggregate concrete (RAC). Therefore, this study provides an experimental evaluation for the steel fiber reinforced recycled concrete aggregate (SFRAC) bearing strength with various percentages (0, 10, 20, 30, 50, and 100%) of recycled concrete aggregate (RCA) substitution. Steel fibre contents of 0.5, 1, 1.5, and 2% were conducted. Three concrete blocks are evaluated (100 × 100 × 100mm, 150 × 150 × 150mm, and 250 × 250 × 250 mm). The ratio of concrete block to bearing area (A2/A1) was maintained at 2.5 throughout three block sizes. The major objective of this study is to investigate stiffness (k), ductility (Δ), residual slip (Sr), residual bearing stress (fbr), ultimate slip (Su), the ultimate bearing stress (fbu), and failure mechanisms for different concrete blocks. The experimental results illustrated that the fbu, fbr and k values of concrete blocks including 10, 20, 30, 50 and 100% of RCA were less than those control samples devoid of RCA. However, nevertheless, the fbu, fbr and k were enhanced with employing various steel fiber percentages. Utilization of RAC enhanced the Su and Δ values. In addition, varying amount of steel fiber improved the Su values of 50% RAC and 100% RAC. Meanwhile, the concrete's ductility was improved as a result of the bearing load-related crack-arresting ability of steel fibers in the concrete blocks. Using a given formula, the ultimate bearing strength of concrete specimens was predicted, and the calculated and experimental results were both reliable.

Evaluation of flexural toughness of polyurethane concrete incorporating various steel fiber length and content

ABSTRACT Polyurethane concrete has excellent mechanical properties, rapid solidification and durability, but brittle damage is easy to occur at room temperature. To solve the problem of insufficient bending toughness of polyurethane concrete, steel fibers were added into the traditional polyurethane concrete to prepare steel fiber polyurethane concrete in this paper. A total of 8 test beams with dimensions of 150 mm × 150 mm × 550 mm were made. The influence of steel fibers with different length-diameter ratios and volume ratios on the flexural strength of polyurethane concrete was studied through four points bending tests. The results show that under the same volume ratio and diameter, as the length of steel fiber increases from 30 mm to 60 mm, the peak load decreased by 8.6%, and the displacement corresponding to the peak load decreased by 41.1%. Under the same length-diameter ratio, the steel fiber volume ratio from 0.5% to 2.0%, the peak load increased by 49.1%, and the displacement corresponding to the peak load increased by 100.8%. The toughening degree, relative initial flexural toughness ratio and relative residual flexural toughness ratio were proposed, and the inconsistencies of calculation criteria for flexural toughness in steel fiber reinforced concrete (JG/T 472–2015) were optimized.

Research on axial compressive behavior of steel-fiber-reinforced recycled concrete-filled square steel tube slender columns

This paper presents an experimental and analytical study of the axial behavior of steel-fiber-reinforced concrete-filled square steel tube slender columns. A total of 25 axially compressive column specimens are manufactured to investigate the effects of the mass replacement percentage of recycled coarse aggregates (Rp), tube wall thickness (Ts), length-to-width ratio of columns (Lc), and steel fiber content (Vsf) on the performance of slender columns. The results show that the effects of Lc and Ts on the compressive behavior of the column specimens are significant owing to changes in the confinement effect and instability. In terms of the bearing capacity, the compressive strength increases by 12.45%–23.19% as Ts increases from 3 to 5 mm but decreases by 4.35%–10.65% as Lc increases from 6 to 12. However, the incorporation of steel fibers improves the post-peak load mechanical behavior of the slender columns by performing anchoring and bridging effects, and when Vsf reaches 1.2%, it tends to compensate for the reduction caused by changes in Lc and Ts. The synergistic action of the column specimens under axial compression is quantified based on an energy consumption indicator. In addition, predictions of the bearing capacity of the slender columns specified in the Eurocode 4, GB 50936-2014, and Han model are compared and discussed. An incremental iteration model is proposed, and the predicted values are similar to the experiment results with reasonable safety margins.