Longitudinal Steel Reinforcement Research Articles

Buckling resistance of steel fibre-reinforced concrete encased steel composite columns

Six steel fibre reinforced high strength concrete (SFRHSC) encased steel columns were tested to investigate their structural performance without the need of conventional longitudinal steel reinforcements and stirrups. The SFRHSC encased steel composite columns were tested until failure under eccentric compression load to determine their buckling resistance including the compression and moment strength interaction behaviour. Furthermore, two composite beams with similar cross-section were subject to four-point load to obtain the load-deflection behaviour and ultimate moment resistance. The experimental results showed that, without the presence of longitudinal steel bar reinforcements, the steel fibre-reinforced composite columns exhibited ductile behaviour and showed no evidence of debonding or early cover spalling. Test evidence showed that the hooked-end steel fibres were able to bridge the growing cracks effectively. Two analytical approaches were proposed to predict the compression and moment resistances of the tested columns. The first model was based on the fibre element analysis, while the second model provided a simplified analytical prediction. Both the models were developed accounting for second-order effects in slender columns. The models were able to predict the test results with reasonable accuracy. The test results also fitted well with the predicted axial force–moment strength interaction curves.

Verification of a Torsional Behaviour Prediction Model for Reinforced Recycled Aggregate Concrete Beams

This study shows the torsional conduct of aggregate streaming beams of reinforced concrete recycling. Pure torsion was perceived for 15 reinforced concrete beams containing recycled concrete aggregates. The beams were grouped into five lengths and cross-sectional groups. The study’s principal parameters were the various percentages of longitudinal steel reinforcement and the proportions of recycled aggregates. The beams were purely twisted until failure and investigated for torsional and crack behaviour. The findings show that the beams with maximum steel enhancement and standard aggregate exhibited maximum cracking power and ultimate torsional strength. Recycled aggregates increased the presence of splitting and the ultimate strength, and the effects of steel strengthening in recycled beams were apparent. In a second analysis, the whole torsional reaction of the beams was analytically predicted. A soft truss model was used and matched with test results for standard beams. A strong compromise was generally reached.

Reactive Powder Concrete Beam's Behavior in Flexural : Review

Reactive Powder Concrete can be considered as a special type of concrete in which the coarse aggregate will be eliminated to get a homogenous microstructure with a maximum density for final result. Many researchers presented a state of the art review on reactive powder's production, mechanical properties, durability, development and applications. But the review about structural behavior is hardly to found. Because of importance of this type of concrete and its structural applications. This paper focused on review the researchers that deals with structural behavior of reactive powder concrete beams under bending load. Also review the proposed design equations related with reactive concrete behavior. Before starting a review of strength , stress-strain relation and ductility are presented because of their importance and effect on structure behavior of beams under bending. According to review of previous studies the type of fibers and its content as volumetric ratio, type of pozalanic materials and its content , amount of longitudinal steel reinforcement are main factors that affected the flexural behavior of reinforced Reactive Powder Concrete

Flexural behavior of hybrid GFRP-reinforced concrete-steel double-skin tubular beams

The hybrid GFRP-concrete-steel double-skin tubular beams (DSTBs) are composed of the outer GFRP tube, the inner steel tube and the sandwich concrete between both tubes. They have attracted the attention of researchers owing to the high ductility, lightweight, corrosion resistance and convenient construction. However, there are few studies on the reinforced DSTBs under bending load compared with the unreinforced DSTBs. Eight circular cross-sectional composite beams are tested in this paper to investigate the flexural behavior, including five reinforced DSTBs, two unreinforced DSTBs and one solid reinforced concrete GFRP tubular beam. The main parameters include the longitudinal steel reinforcement ratio, the inner steel tube diameter, the GFRP tube thickness, and the concrete strength. The results show that all the composite beams exhibit ductile flexural failure, and the average displacement ductility factor of the reinforced DSTBs is 3.85. The arrangement of longitudinal steel bars significantly enhances the bearing capacity and reduces the mid-span deflection of the composite beam, and it is recommended to use a reasonable low steel ratio for the excessive steel reinforcement is adverse to the ductility. Increase of the inner steel tube diameter greatly improves the flexural capacity on premise of ensuring the stiffness and ductility. The outer GFRP tube provides moderate hoop confinement on the compressive concrete in the pure bending members, which limits the increasing extent of the flexural capacity. Reasonable confinement stiffness is suggested for the reinforced DSTBs to avoid insufficient or excessive constraint. Besides, concrete with sufficient compressive strength is recommended to be used in the hybrid DSTBs for it increases both the flexural capacity and the initial stiffness of the beam.

Analytical Review on Eccentric Axial Compression Behavior of Short and Slender Circular RC Columns Strengthened Using CFRP.

Although reinforced concrete (RC) columns subjected to combined axial compression and flexural loads (i.e., eccentric load) are the most common structural members used in practice, research on FRP-confined circular RC columns subjected to eccentric axial compression has been very limited. More specifically, the available eccentric-loading models were mainly based on existing concentric stress–strain models of FRP-confined unreinforced concrete columns of small scale. The strength and ductility of FRP-strengthened slender circular RC columns predicted using these models showed significant errors. In light of such demand to date, this paper presents a stress–strain model for FRP-confined circular reinforced concrete (RC) columns under eccentric axial compression. The model is mainly based on observations of tests and results reported in the technical literature, in which 207 results of FRP-confined circular unreinforced and reinforced concrete columns were carefully studied and analyzed. A model for the axial-flexural interaction of FRP-confined concrete is also provided. Based on a full parametric analysis, a simple formula of the slenderness limit for FRP-strengthened RC columns is further provided. The proposed model considers the effects of key parameters such as longitudinal and hoop steel reinforcement, level of FRP hoop confinement, slenderness ratio, presence of longitudinal FRP wraps, and varying eccentricity ratio. The accuracy of the proposed model is finally validated through comparisons made between the predictions and the compiled test results.

Bond Behaviour of Near-Surface Mounted Strips in RC Beams-Experimental Investigation and Numerical Simulations.

This paper presents an investigation of the bond mechanism between carbon fibre reinforced polymer (CFRP) laminates, concrete and steel in the near-surface mounted (NSM) CFRP-strengthened reinforced concrete (RC) beam-bond tests. The experimental program consisting of thirty modified concrete beams flexurally strengthened with NSM CFRP strips was published in. The effects of five parameters and their interactions on the ultimate load carrying capacities and the associated bond mechanisms of the beams are investigated in this paper with consideration of the following investigated parameters: beam span, beam depth, longitudinal tensile steel reinforcement ratio, the bond length of the CFRP strips and compressive concrete strength. The longitudinal steel reinforcement was cut at the beam mid-span in four beams to investigate a better assessment of the influence of the steel reinforcement ratio on the bond behaviour of CFRP to concrete bond behaviour. The numerical analysis implemented in this paper is based on a nonlinear micromechanical finite element model (FEM) that was used for investigation of the flexural behaviour of NSM CFRP-strengthened members. The 3D model based on advanced CFRP to concrete bond responses was introduced to modelling of tested specimens. The FEM procedure presents the orthotropic behaviour of the CFRP strips and the bond response between the CFRP and concrete. Comparison of the experimental and numerical results revealed an excellent agreement that confirms the suitability of the proposed FE model.

Experimental evaluation of flexural behavior of High-Performance Fiber Reinforced Concrete Beams using GFRP and High Strength Steel Bars

Substitution of only steel rebar with fiber-reinforced polymer (FRP) or in combination with steel rebar has been recommended to reduce corrosion effects in steel rebar. This paper has pursued the impact of hybrid concrete beams reinforced with High Strength Steel Bars (HSS) and Glass Fiber-Reinforced Polymer Bars (GFRP) manufactured employing High-Performance Fiber-Reinforced Cementitious Composites (HPFRCC) instead of conventional concrete through experimental tests. Seven concrete beams including conventional concrete and HPFRCC in three separate groups, having identical compressive strengths and longitudinal steel reinforcement ratios, have been tested following respected codes and regulations to supply sufficient development lengths using GFRP headed bars, under four-point loading tests. The first and second groups, each represented one conventional concrete beam and an HPFRCC model with GRFP or HSS; the third group included three HPFRCC beams using GRFP and Steel rebar to assess flexural behavior of beams under different reinforcement ratios. Experimental results indicated that HPFRCC beams demonstrated improvements in their load capacity, flexural strength, bending stiffness, ductility, and energy absorption compared to similar conventional concrete beams. Also, in hybrid beams compared to steel reinforced concrete beams both cast with HPFRCC, the more the effective reinforcement ratio of both single and hybrid bars increased, the more ductility was improved between 37 and 88 percent. Displacement ductility of hybrid beams having effective reinforcement ratios up to 1.35 and 1.25 times more than the balance ratio was increased 23 and 37.5 percent, respectively. Energy absorption for HPFRCC beams reinforced only with GFRP or steel rebar was increased 31 and 250 percent compared to identical conventional concrete beams, respectively. In hybrid compared to GFRP reinforced beams both cast with HPFRCC, the more effective reinforcement ratio increased, the more energy absorption was increased in a range of 51 up to 174 percent. Therefore, it can be concluded that using the hybrid of GFRP and HSS bars result in up to 30 percent improvement in flexural strength because of the effective performance of GFRP after steel rebar yielding and ductility increase due to HSSs yielding.

Effects of Corrosion on Stress–Strain Behavior of Confined Concrete

An analytical model is proposed to predict the stress–strain relationship of confined concrete subjected to reinforcement corrosion. The stress–strain graph of confined concrete with corroded reinforcement was predicted using estimation of four key parameters: maximum compressive stress, strain at maximum compressive stress, modulus of elasticity of concrete, and ultimate compressive strain of concrete. To validate the model, analytically predicted stress–strain curves of confined concrete of circular RC columns damaged due to corroded reinforcement were compared with those obtained from full-scale experimental tests with varying degrees of corrosion. The results of the comparison indicate good agreement. The RC columns had identical size, the same longitudinal steel reinforcement and spiral confinement type but with different spiral pitches providing varying levels of confinement. The corroded RC columns were categorized into four corrosion groups: noncorroded, low corrosion, high corrosion, and mechanical pitting corroded. The presented model is based on a modified version of the Mander’s universal model for RC columns.

Nonlinear modeling of a damaged reinforced concrete building and design improvement behavior

Nonlinear modeling is performed for a reinforced concrete building that presented flexural damage during the 2010 Chile earthquake. The focus of the analysis is the behavior of a wall on the first floor that presented localized damage; the wall is T-shaped, has a web length of 8 m, and a flange length reaching 18 m. An unconfined concrete model and a steel model incorporating buckling were considered, accounting for the poor detailing of the wall boundary element. The walls were modeled using nonlinear fiber elements. A rigid diaphragm was considered, and the slabs were incorporated only in areas where they could generate coupling effects in the walls, being modeled as beams with plastic hinges at their ends. Nonlinear static and dynamic analyses were performed on the building model, utilizing records for Santiago from the 2010 Mw 8.8 earthquake. For relatively low lateral drift values (~0.003), the strain levels observed in the model for the wall suffering damage would lead to flexural damage due to its large size, large amount of longitudinal steel reinforcement in the flange, and poor detailing of the web boundary. Several other nonlinear models were created to compare the impact of the design improvements on the overall performance of the building. From the results, it can be seen that the observed damage would be avoided by implementing design solutions such as increased wall thickness, confinement, or decoupling of the main wall.

3D concrete printing of permanent formwork for concrete column construction

This study investigated 3D concrete printing of permanent formwork for concrete column construction. The effect of different hydroxypropyl methyl cellulose (HPMC) contents (0, 0.0003 and 0.0006 by mass of binder) and the water-to-binder (W/B) ratios (0.27, 0.29 and 0.31) on the rheological properties, structural build-up and mechanical performance were studied using several mixtures for manufacture of the permanent formworks. The results showed that the mixture with the HPMC = 0.0006 and the W/B = 0.27 showed the maximum static yield stress, largest thixotropy and maximum green strength, and thereby selected as the optimum mixture. The plastic failure of the optimum mixture was also predicted using a thixotropy model and was compared with the experimental results. Subsequently, three concrete columns with different longitudinal steel reinforcement ratios (0.0%, 1.9% and 2.5%) were constructed using the printed concrete as the permanent formwork and tested in compression. Good bonding was observed at the interface of the cast-in-place concrete and the printed concrete permanent formwork. In addition, it was observed that the initial stiffness, the maximum bearing capacity and the corresponding longitudinal displacement of the concrete columns increased, as the longitudinal reinforcement ratio increased. The counterpart concrete columns using the conventional formworks were also constructed and tested for comparison. In comparison, the concrete columns made using the printed concrete as the permanent formwork obtained a higher stiffness and bearing capacity than the counterpart conventional concrete columns. The reasons for the differences are explained.

Mechanical properties of engineered cementitious composites beams fabricated by extrusion-based 3D printing

Engineered cementitious composites (ECC) is emerging as promising candidate cementitious materials for 3D concrete printing (3DCP). This paper experimentally investigated the bending behaviors of 3D printed ECC beams with different geometric configuration. A novel mix design for ECC with ultra-high molecular weight polyethylene (PE) fiber was developed and the PE-ECC beams were casted by two methods, i.e., mold-cast and extrusion-based 3D printing. The four-point bending tests were conducted for plain ECC beams, reinforced concrete (RC) beams as well as cast-in-situ unreinforced ECC beam. The influences of different parameters including fabrication methods, print angles and superposition types were particularly investigated. The anisotropic mechanical properties under bending of printed beams and bending capacity of cast in place reinforced concrete beams were also investigated. Also, the strain distribution of longitudinal steel reinforcement in reinforced concrete as well as printed ECC beam were studied. The results indicated that the printed ECC beam presented a ductile failure mode accompanied with strain hardening behaviors. Also, the ECC beams exposed to z direction loading showed better mechanical anisotropic properties when compared with those exposed to x direction.

Lateral cyclic response sensitivity of rectangular bridge piers confined with UHPFRC tube using fractional factorial design

Through the use of ultra-high performance fiber reinforced concrete (UHPFRC) tubes in an RC bridge pier, the pier can substantially reduce seismic damages during earthquakes compared to the conventional RC piers. The seismic behavior of such a novel bridge pier is affected by various design factors. This study aims at identifying the significant levels of each main factor and their interactions which affect the cyclic response of UHPFRC tube-confined pier. A fractional factorial design methodology is used to statistically estimate the effects of different main factors and their interactions. 3D finite element models of the UHPFRC tube-confined columns are first generated and validated by using experimental results. Then, a sensitivity study is conducted considering ten potential material and geometry-related factors. Five response variables, i.e. the initial stiffness, load-carrying capacity, residual drift, hysteretic energy dissipation, and equivalent viscous damping, for the UHPFRC tube-confined column are examined. From the parametric study, the significant factors including the main factors and their interactions are determined for each response variable. According to the sensitivity analysis results, predictive equations are proposed to predict the response quantities for other UHPFRC tube-confined columns with the same column cross-section through regression analysis. Results demonstrate that the longitudinal steel reinforcement ratio, axial load ratio, and aspect ratio have large effects (with total contributions greater than 40%) on all the response variables.

Fatigue design in reinforced concrete bridges according to Brazilian code

There has been an increase in the flow of freight vehicles commuting on Brazilian highways. Then, special attention to the structural performance of bridges regarding the fatigue in beams is needed. Brazil has neither normative metrology to study real data flow of vehicles, nor specific fatigue load train models and coefficients to the analysis and design of road bridges. The same load train that is used for general dimensioning, TB 450, is used for the fatigue verification. Hence, this work aims to verify if the current TB 450 is representative of the freight heavy vehicles with 2 to 9 axles concerning the effects of fatigue in the longitudinal reinforcement of beams of theoretical reinforced concrete bridges with two, three, and five beams. This verification is performed analyzing the stress variations found in the longitudinal reinforcement of vehicles with 2 to 9 axles and the TB 450. Based on the results, the longitudinal steel reinforcement was more susceptible to fatigue's effects. Freight vehicles with 5, 6, 8 and 9 axles presented the most significant stress, therefore, they tend to cause more deleterious effects. Hence, the adoption of a Brazilian normative fatigue specific load train and coefficients is necessary to analyze pre-existing road bridges and design new ones most accurately.

The P-y Response of Laterally Loaded Flexible Piles in Residual Soil

This paper describes the main features related to lateral displacements with depth after successive lateral loading–unloading cycles applied to the top of reinforced-concrete flexible bored piles embedded in naturally bonded residual soil. The bored piles under study have a cylindrical shape, with 0.40-m in diameter and 8.0-m in length. Both bored piles types (P1 and P2) include an embedded steel pipe section in their center as longitudinal steel reinforcements: pile type P1 has another 16 steel rods as steel reinforcement to concrete while pile type P2 has no further steel reinforcement. Pile type P1 has three times as much stiffness (EI) and four and a half times the plastic moment (My) than pile type P2. A similar load–displacement performance was observed at initial loads as for small displacements of both piles. At this initial loading stage, the response of the reinforced concrete piles is a function of the soil characteristics and of a linear elastic pile deformation. During this stage, piles can even be understood as probes for evaluating soil reactions. For larger horizontal displacements, after the concrete section starts undergoing large deformations, approaching the ultimate bending moment, pile behavior and consequently the load–displacement relation starts to diverge for both piles. For pile P1 the values of relevant lateral displacements are extended to about 2.5-m in depth, while for pile P2 lateral displacements are mostly constrained to about 2.0-m in depth. Measurements of horizontal displacements of pile P1 against depth recorded with a slope indicator show that, after unloading, lateral loads at distinct stages (small and near failure loads), exhibits a much higher elastic phase of the system response. An analytical fitting model of soil reaction is proposed based on the measured displacements from slope indicator. The integration of a continuous model proposed for the soil reaction agrees fairly well with the measured displacements up to moments close to plastic limit. Results of load–displacement show that the stiffer pile (P1) was able to mobilize twice as much lateral load compared to pile P2 for a service limit displacement of about 20 mm. The paper shows results that enable the isolation of the structural variable through real scale pile load tests, thus granting understanding of its importance and enabling its quantitative visualization in examples of piles embedded in residual soil sites.

Flexural Strengthening of Substandard Reinforced Concrete Bridge Wall Piers with CFRP Systems under Cyclic Loads

Reinforced concrete bridge wall piers constructed according to older codes experience damage during earthquakes, which can lead to bridge collapse. Deficiencies include inadequate design and detailing of longitudinal and transverse steel reinforcement and deficient lap splices. Three wall piers were constructed using as-built reinforcement details conforming to pre-1973 requirements to evaluate flexural strengthening strategies. The first wall pier was used as the control specimen. The second wall pier was retrofitted using carbon fiber-reinforced polymer (CFRP) jackets and transverse CFRP anchors placed through the section for the confinement of the lap-spliced region and vertical CFRP anchors to improve flexural capacity. The third wall pier was retrofitted similarly to the second pier by using vertical near-surface mounted (NSM) CFRP rods. The piers were tested under cyclic lateral load until failure. Both retrofitted wall piers were able to achieve significantly higher flexural capacity, stiffness, and hysteretic energy dissipation when compared with the control wall pier specimen. The as-built wall specimen was not able to develop the theoretical flexural capacity due to lap splice clamping failure; both retrofitted specimens exceeded the theoretical flexural capacity of the as-built wall specimen.

Numerical investigation of the parameters influencing the behavior of dapped end prefabricated concrete purlins with and without CFRP strengthening

Dapped end prefabricated concrete purlins (PCPs) suffer from shear damages due to coating, snow, wind load and also their dead loads. In this present study, a series of numerical modelling is performed with the aid of finite element program ABAQUS in order to investigate this behavior of PCPs through parametric study. In addition to the mechanical properties of the PCPs, the strengthening of the PCPs with the help of carbon fiber reinforced polymers (CFRP) is considered as a parameter in the models. Pursuant to this aim, longitudinal steel reinforcement ratio, shear friction reinforcement ratio, bending reinforcement ratio, suspension reinforcement ratio, concrete and steel mechanical properties, pre-stressing level, CFRP ply orientation, the number of CFRP plies and material properties of CFRP composite were selected as the parameters. First of all, numerical models were verified using experimental test data of three PCP test specimens and five CFRP coupon tests. Later, a total of 50 different numerical models was created to investigate the behavior of PCPs thoroughly. Vertical load- displacements curves are compared and explained in detail. The result of the parametric study revealed that the effects of the parameters related to reinforced concrete except longitudinal reinforcement and material properties of concrete are very limited when compared to the effects of the parameters related to CFRP. The effect of FRP ply orientation is the most effective parameter that increases significantly the shear capacity of PCPs. More importantly is the general FRP layout is proposed to delay or prevent shear cracks for the beams and the proposed layout is proved through numerical analyses. [±45°] fiber orientation is recommended to use to prevent shear damage.

Flexural strengthening of over-reinforced concrete beams with highly ductile fiber-reinforced concrete layer

This study investigates the effectiveness of highly ductile fiber-reinforced concrete (HDC), which is characterized by its high ultimate compressive strain ability, in improving the failure mode and deformational characteristics of over-reinforced concrete beams. The flexural behavior of over-reinforced concrete beams strengthened with HDC was experimentally investigated. The variables included the tensile longitudinal steel reinforcement ratio, thickness of the layer, strengthening materials, and strengthening methods. The crack pattern, failure mode, load–deflection responses, flexural capacity, ductility, and strain were investigated. The experimental results indicated that applying HDC to strengthen the compression zone of an over-reinforced concrete beam is a highly effective method to change its brittle failure and improve the ductility. HDC-strengthened beams showed an increase in flexural capacity and deformation compared to normal concrete-strengthened beams with equal strengthening thickness. A better deformation capacity can be achieved by using a larger thickness of the strengthening layer, ensuring the coordination between the strengthening layer and the existing beam. The effectiveness of HDC in strengthening over-reinforced concrete beams was improved as the tensile longitudinal steel reinforcement ratio increased. A simplified calculation method for the flexural capacity of HDC-strengthened beams was proposed, which is in good agreement with the experimental results. The compression zone relative depth for the balanced failure could be notably improved by applying a larger thickness to strengthen the compression zone of over-reinforced concrete beams than the critical thickness of the HDC layer, which can be calculated by the proposed approach.

Numerical Study on Flexural Behavior of Concrete Beams Strengthened with Fiber Reinforced Cementitious Matrix Considering Different Concrete Compressive Strength and Steel Reinforcement Ratio

Concrete structures retrofitted with fiber reinforced cementitious matrix (FRCM) have become widespread due to their mechanical and durability performances. However, the behavior of FRCM -strengthened RC members under service loads is still a concern, and more efforts need to be done. In this study, a nonlinear three-dimensional finite element (FE) model has been developed to study the performance of reinforced concrete (RC) beams strengthened by (FRCM). The model was validated against the experimental results gathered from six beams tested under three-bending points. Consequently, the primary numerically studied parameters were longitudinal steel reinforcement ratio and concrete compressive strength. A cohesive damage parameters were investigated to represent the experimental results. Also, the theoretical flexural capacity of strengthened beams based on ACI-549 code was evaluated based on the numerical method results. As a conclusion, the numerical results are in a very good agreement with the experimental ones regarding yielding load, ultimate load, and failure mode. In addition, the developed models from parametric studies concluded the insignificant effect of concrete compressive strength on increasing the ultimate capacity of strengthened beam. However, the steel reinforcement ratio has a major impact on enhancing the ultimate capacity of strengthened beams.

Feasibility and flexural behavior of RC beams prestressed with straight unbonded aluminum alloy tendons

This paper investigates the feasibility and flexural behavior of reinforced concrete beams internally prestressed with straight unbonded aluminum alloy tendons by testing five partially prestressed beams and one reference beam. For each beam specimen, load-deflection curves, failure modes and cracking behavior, the relationship between load and strains in steel and prestressing aluminum alloy tendons were examined and analyzed. In particular, the effects of effective prestress, combined reinforcement index (CRI), and partial prestressing ratio (PPR) on flexure of concrete beams were discussed. The test results indicated that the spacing and width of concrete cracks of prestressed beams containing the same amount of bonded longitudinal steel reinforcement decreased with the increase of effective prestress, and the combined reinforcement index governs flexural behavior of the prestressed beams. The flexural crack width and displacement ductility exhibited a reduction with the increase of CRI. In addition, an analytical model was established to calculate the flexural strength and corresponding deflection at midspan of the concrete beams internally prestressed with unbonded aluminum alloy tendons by suggesting a new simplified curvature distribution, which is more accordant with the original curvature distribution. The proposed model provides a relatively good estimation of the flexural capacity and midspan deflection of the prestressed beams.

Mechanical performance of CFRP enclosed reinforced concrete beams by different shear reinforcement

This paper aims to study the flexural behavior of CFRP enclosed reinforced concrete beams with different shear reinforcement. Four-point bending tests were carried out on six concrete beams with different contents of steel fibers (0.5%, 1.0%, and 1.5%) as well as six beams with different stirrup spacing (100 mm, 150 mm, and 300 mm) without fiber. The effect of steel fiber (SF) content as well as stirrup spacing on flexural properties of concrete beams were investigated. Meanwhile, the effect of expansive agent on the properties of specimens was also studied. The data collected in this test include cracking load, ultimate load, mid-span deflection, strain of CFRP (Carbon fiber reinforced polymer), strain of longitudinal steel reinforcement as well as the failure modes. Test results show that both cracking loads and ultimate loads of the SF reinforced beam specimens are generally higher than those of the corresponding stirrup reinforced beam specimens. Experimental results also indicate that the addition of SF can improve the ductility and cracking resistance of specimens. This therefore demonstrates that it is feasible to replace stirrup reinforcement with SF as shear reinforcement. In addition, it exhibits a good agreement between experimental results and analytical predictions in cracking loads and ultimate loads.