Tension Reinforcement Ratio Research Articles

Shear strength behavior of reinforced concrete T-beams without web reinforcement

To investigate the influencing factors of shear strength for reinforced concrete beams without web reinforcement, 36 reinforced concrete beams were tested: 27 with a T-shaped section and 9 with a rectangular section. The experiments were designed to analyze the impact of various parameters on the shear strength behavior, including the shear span ratio, tension reinforcement ratio, and beam shape. The experimental findings indicate that each variable has a significant improvement, particularly, the contributions of the flange on the shear behavior of RC beams. Based on collected the shear database, two proposed equations were established and verified against the suggested equations in several international codes. The proposed equations herein exhibit an incredible, accurate, and consistent predictions of shear behavior of the beams. Additionally, the collected dataset was analyzed using various machine learning algorithms to explore the applicability; the results demonstrate that the modern data-driven techniques can provide an efficient and reliable prediction for the shear behavior.

Evaluation of moment-curvature response and curvature ductility of reinforced UHPC cross-sections

This study deals with the evaluation of moment-curvature response and curvature ductility of reinforced ultra high performance concrete (R-UHPC) cross-sections. Curvature ductility is calculated based on six definitions. The impact of these definitions is demonstrated through the calculation of strength reduction factors and comparisons of factored flexural strength of R-UHPC and reinforced normal strength concrete (R-NSC) cross-sections. Strategies for improving the curvature ductility of R-UHPC cross-sections are presented. A versatile framework to predict the complete moment curvature response of R-UHPC cross-sections is proposed. The proposed procedure is used to study the effect of tension reinforcement ratio, UHPC strain at crack localization, UHPC tension model, UHPC ultimate tensile strain, and compression reinforcement ratio on curvature ductility and complete moment curvature response. It is determined that for a given cross-section, changing the material from NSC to UHPC causes notable reductions in curvature ductility. This reduction applies to: 1) tension and compression reinforcement ratios that range from 0.69–2.78 % and 0 – 1.37 %, respectively; 2) UHPC tension models that feature elasto-plastic and linear strain hardening responses with and without residual branches; and 3) UHPC ultimate tensile strains that range from 0.005–0.015. Such reductions in curvature ductility render the considered R-UHPC cross-sections as members in the transition zone – a classification currently prohibited for R-NSC sections according to ACI 318–19 (22) - while their R-NSC counterparts qualify as tension-controlled. This results in lower strength reduction factors for R-UHPC cross-sections and limits the benefits of UHPC when flexural strength controls design. It is concluded that R-UHPC cross-sections that feature either the highest or the lowest reinforcement ratios provide the highest added benefit from the point of view of enhancing factored flexural strength compared to R-NSC sections. The most effective method to elevate curvature ductility is an increase in the UHPC strain at crack localization. A minimum UHPC strain at crack localization of 0.006 is required to change the classification of cross-sections from the transition zone to tension-controlled. The use of compression reinforcement - an established technique for R-NSC members to induce a change in the flexural failure mode by elevating curvature ductility - was determined to have almost no influence on the curvature ductility of R-UHPC cross-sections.

Parametric study on the flexural behavior of steel fiber reinforced concrete beams utilizing nonlinear finite element analysis

Reinforced concrete beams undergo significant internal forces and deformations under extensive loading and have flexural or shear failure based on the reinforcement detailing and geometric properties. The addition of steel fibers increases the deformation and load carrying capacities that leads to ductile behavior. The main contribution of fibers is the improvement of the composite tensile capacity, which results in improved flexural and shear responses. This study numerically investigates the effect of fiber properties on the flexural behavior of steel fiber reinforced concrete (SFRC) beams for both compression and tension failure. First, three specimens from prior experimental studies are modeled using the nonlinear finite element program ABAQUS and the analytical results are verified by comparison with the test results. Contrary to prior nonlinear models, the developed model accurately predicts the damage pattern, descending portion of the load-displacement relationship, and ultimate displacement, which lead to a reliable estimation of energy dissipation capacity and ductility. A comprehensive parametric study is then conducted to examine the effect of tension reinforcement ratio, fiber volume fraction, and fiber aspect ratio on the flexural behavior of both reinforced concrete and SFRC beams. The influence of these key parameters is investigated by comparing the peak load, displacement ductility, peak stiffness, service stiffness, energy dissipation capacity, and damage pattern for both reinforced concrete and SFRC beams. The analytical results indicate that the addition of steel fibers up to 2.0 % leads to a slight increase in the load carrying capacity, while the displacement ductility and energy dissipation capacity are significantly improved. Furthermore, the utilization of 1.0 % steel fibers is observed to be sufficient to modify the failure mode of over reinforced concrete beams from brittle compression failure to tension failure.

Impact response analysis and prediction of FRP-RC beams with varying flexural stiffness: Numerical simulation and modified two-DOF calculation

The damage behavior and simplified calculation of fiber-reinforced polymer reinforced concrete (FRP-RC) beams subjected to impact loading have attracted substantial attention. In this study, a finite element model incorporating strain rate was employed. Based on the model, the progressive damage behavior and nonlinear impact response of FRP-RC beams with varying stiffness under hammer-to-beam mass ratios were examined. The results indicate that in the investigated conditions, the damage mode of FRP-RC beams does not vary with the changes in the tension reinforcement ratio, but is affected by the hammer-to-beam mass ratio. Due to the absence of a yielding stage for FRP bars, a nonlinear alteration occurred in the rebound of the FRP bars’ strain and the beam’s displacement with a redistribution of stress. When the reinforcement ratio varies from 0.32% to 3.37%, the peak displacements, reaction and impact forces vary by 25%-49%, 53%-78%, and 0.1%-1% under different mass ratios, respectively. The reinforcement ratio does not change the relationship between the mass ratio and the curve shape of the impact force time history. Additionally, an improved two-degree-of-freedom model considering the FRP’s elastic brittleness effect and modified contact stiffness scaling factor was developed, their accuracy was verified. However, there are still many inconveniences to applying the two-DOF model in engineering. Consequently, based on the above two-DOF model, explicit formulas considering contact stiffness, bending stiffness, impactor velocity and mass for displacement and impact force response of impacted FRP reinforcement concrete beams were proposed, which greatly facilitates engineering calculations.

Shear Behaviour of RC Beams: A Numerical Study

A two-dimensional (2D) nonlinear finite element (FE) model created for reinforced concrete (RC) beams is presented in this paper. The FE model was verified in order to perform further parametric studies on RC beams with and without existing steel shear links. The parameters were tension reinforcement ratio, concrete compression strength, and beam size. Moreover, the accuracy of “Turkish Standards 500: Requirements for design and construction of reinforced concrete structures (TS500)” in terms of predicting the total shear force capacity of RC beams was examined. The FE model properly captured the experimental load capacity, with a mean value of 1.04. The increase in overall shear force capacity caused by the increasing tension reinforcement ratio from 1.79 to 3.33% was 18.3% for RC beams with existing steel shear links, whereas it was 10.6% for RC beams without existing steel shear links. The total shear force capacities of RC beams with and without steel shear links increased once concrete compression was increased from 30 to 70 MPa. An increasing beam size resulted in a reduction in shear stress at failure of 33.8% and 32.7% for RC beams with and without shear links, respectively. TS500 design code gave conservative results in calculating the overall shear force capacity of RC beams.

Curvature Ductility Factor of Reinforced Concrete Beams with Confinement under Different Strain Rates of Loading

The purpose of this work is to investigate the influence of confinement on the curvature ductility factor of reinforced concrete beams at low and high strain rates of loading. The curvature ductility of beams is affected by the tension reinforcement ratio, the compression-reinforced ratio, the compression strength of concrete <img src=image/14828877_01.gif>, and the yield strength of steel <img src=image/14828877_02.gif>. The degree of transverse reinforcement is another component that determines beam flexural behavior. A model of steel and restricted concrete under varying strain rates of loading was utilized to compute the curvature ductility factor. The reinforced concrete section is studied in this research to determine the confinement of the beam and the different strain rates of loading. The ratio of the volume of rectangular steel hoops to the volume of the concrete core, <img src=image/14828877_03.gif>, represents the confinement. Six values of <img src=image/14828877_03.gif> are investigated to ensure an acceptable degree of ductility capacity. It is concluded that the ACI-Code balanced reinforcement ratio is impacted by confinement, and that it is lower than the ratio achieved when confinement is present. In this work, specific values of the curvature ductility factor for beam sections constructed with the ACI code were reported for <img src=image/14828877_02.gif>=60 ksi (414 MPa), <img src=image/14828877_01.gif>=4 ksi (27.6 MPa). Furthermore, the maximum quantity of tension reinforcement max influences the curvature ductility factor.

Prediction of shear strength of RC deep beams using XGBoost regression with Bayesian optimization

For the shear strength of deep beams, most of current design codes adopt the strut-and-tie model. However, since the shear resistance mechanism of deep beams is quite complicated and shear failure could be catastrophic with no prior warning, more reliable and robust shear strength prediction models are required. To this end, in the present study, using the extreme gradient boosting (XGBoost) and Bayesian optimization (BO) algorithms, a BO-XGBoost hybrid model was developed and its hyperparameters were optimized based on a database of 320 test specimens. The prediction accuracy of the proposed BO-XGBoost hybrid model was compared with G-XGBoost (with hyperparameters tuned by grid search), R-XGBoost (with hyperparameters tuned by random search), D-XGBoost (with default hyperparameters), and existing design equations, and the comparison showed that the proposed model can predict most accurately the shear strength of deep beams without any significant and evident bias. The parametric study using the proposed model revealed that the effective depth, beam width, shear span-to-depth ratio, tension reinforcement ratio, and concrete compressive strength are critical to the shear strength of deep beams. For ease and convenience of the utilization of the proposed model, a stand-alone application program was also developed.

Numerical investigation on DE-strengthened-RC beams without steel shear reinforcement

This study presents a two-dimensional nonlinear finite element (FE) model for Deep Embedment (DE) strengthened reinforced concrete (RC) beams without existing steel shear links. The FE model was developed and validated against experimental results reported in published literature. The parametric study was thereafter conducted to examine important parameters influencing the strengthened behavior. The parameters were concrete compressive strength, beam width, beam size, and tension reinforcement ratio. The FE model accurately predicted experimental results with a mean predicted-to-experimental value of 1.04. The FE results showed that the percentage of shear strength provided by embedded steel bars was almost constant once both concrete strength and tension reinforcement ratio were increased. However, an increase in the beam width resulted in a decrease in the percentage of shear strength gain due to embedded steel bars. Shear stress at failure decreased once beam size was increased for both unstrengthened (control) and DE-strengthened beams. The percentage of shear strength provided by embedded steel bars decreased from 47.9% to 27.6% as effective depth was increased from 261.5 mm to 523 mm.

Enhancement of RC T‐beams toughness using laced stirrups reinforcement for blast response predictions

AbstractThe dynamic behavior of laced reinforced concrete (LRC) T‐beams could give high‐energy absorption capabilities without significantly affecting the cost, which was offered through a combination of high strength and ductile response. In this paper, LRC T‐beams, composed of inclined continuous reinforcement on each side of the beam, were investigated to maintain high deformations as predicted in blast resistance. The beams were tested under four‐point loading to create pure bending zones and obtain the ultimate flexural capacities. Transverse reinforcement using lacing reinforcement and conventional vertical stirrups were compared in terms of deformation, strain, and toughness changes of the tested beams. The inclination angles of the used lacing reinforcement with respect to the longitudinal reinforcement were 45° and 60°. The lacing reinforcement was efficient and participated actively in resisting the bending moments and shear forces at the same time. For the same diameter of lacing reinforcement, the 60° inclination angle imposed more ductility before failure than beams with lacing reinforcement of a 45° inclination angle. Moreover, the lacing bar diameter was more effective in improving the load‐carrying capacities when using the inclination angle of 45°. A finite element (FE) model was developed and validated using the experimental results based on the measured deformations and strains to conduct a parametric study. The investigated parameters included the effect of the arrangements of the applied loads, laced rebar diameter, inclination angle, tension reinforcement ratio, and concrete strength.

Improvement in Bending Performance of Reinforced Concrete Beams Produced with Waste Lathe Scraps

In this study, the impacts of different proportions of tension reinforcement and waste lathe scraps on the failure and bending behavior of reinforced concrete beams (RCBs) are clearly detected considering empirical tests. Firstly, material strength and consistency test and then ½ scaled beam test have been carried out. For this purpose, a total of 12 specimens were produced in the laboratory and then tested to examine the failure mechanism under flexure. Two variables have been selected in creating text matrix. These are the longitudinal tension reinforcement ratio in beams (three different level) and volumetric ratio of waste lathe scraps (four different level: 0%, 1%, 2% and 3%). The produced simply supported beams were subjected to a two-point bending test. To prevent shear failure, sufficient stirrups have been used. Thus, a change in the bending behavior was observed during each test. With the addition of 1%, 2% and 3% waste lathe scraps, compressive strength escalated by 11.2%, 21.7% and 32.5%, respectively, compared to concrete without waste. According to slump test results, as the waste lathe scraps proportion in the concrete mixture is increased, the concrete consistency diminishes. Apart from the material tests, the following results were obtained from the tests performed on the beams. It is detected that with the addition of lathe waste, the mechanical features of beams improved. It is observed that different proportions of tension reinforcement and waste lathe scraps had different failure and bending impacts on the RCBs. While there was no significant change in stiffness and strength, ductility increased considerably with the addition of lathe waste.

Effect of Design Parameters on the Flexural Strength of Reinforced Concrete Sandwich Beams

Sandwich beams are preferable for aerostructure and marine structures due to their high mechanical strength, durability, stiffness, and fatigue resistance. This paper presents a study on the flexural behavior of sandwich beams made of self-compacting concrete comprising a polystyrene inner core with wire mesh reinforcement. The effect of the design parameters such as the inner core area, percentage of tension reinforcement, and wire mesh on the moment carrying capacity and failure modes of sandwich beams was analyzed. Ten beams were cast and tested to failure with simply supported end conditions and they were classified into three different groups. The longitudinal section of the inner core area was varied by 0% (control beam), 25%, 50%, and 75% of the gross area. The tension reinforcement ratio varied between 0.6 and 1.5%. In addition, the effect of the wire mesh in shear and flexural resistance was studied. The load-carrying capacity of sandwich beams increased with flexural reinforcement. In addition, the welded wire mesh improved the sandwich beams’ flexural and shear performance. The conventional expressions for the moment of resistance were valid for sandwich beams, whereas the shear strength expressions overestimated the capacity; therefore, modifications were suggested. The refined models had a significant agreement with the experimental results.

Shear-flexural cracking strength of RC beams with external vertical prestressing rebars: Theoretical investigation and numerical simulation

This paper presents a semi-theoretical empirical formula to predict the shear-flexural cracking strength of an RC beam enhanced with the external vertical prestressing rebar (EVPR) technique. Besides, nonlinear finite element models (FEM) created by software ABAQUS were used to analyze the effect of crucial parameters on the shear-flexural cracking strength. The parameters involve shear span-to-depth ratio, concrete strength, longitudinal tension reinforcement ratio, initial pulling force and spacing of EVPRs, and the vertical stiffness of the EVPR supports. Results show that the cracking strength increased linearly with the tensile strength of the concrete and the initial pulling force. The small shear span-to-depth ratio was predominantly conducive to the cracking strength. Adequate longitudinal tension rebars contributed to the cracking strength improvement. A reasonable EVPR spacing was recommended to ensure the cracking strength. Greater vertical stiffness of the EVPR supports can ensure higher compressive stress for the RC beam to improve the cracking strength.

Flexural performance of reinforced concrete beam made with waste foundry sand as fine aggregate

PurposeThe structural behavior of reinforced concrete (RC) beams made with waste foundry sand (WFS) was examined in this study by using investigational data. Five RC beams were tested in this present work, four beams with varying WFS content and one beam with natural aggregates. The factors considered for studying the flexural performance of RC beams were WFS content (10%, 20%, 30% and 40%), 15% Ground Granulated Blast Furnace Slag (GGBS) is used as supplementary cementitious (SCM) content for all beams and tension reinforcement ratio (0.95%). The crack pattern of the RC beams with WFS (RCB1, RCB2, RCB3 and RCB4) was similar to that of referral beam–RCB0. The RC beams made with WFS (RCB1, RCB2, RCB3 and RCB4) show lesser number of cracks than referral beam–RCB0. It is observed that RCB1 beam shows higher ultimate moment carrying capacity than other RC beams. A detailed assessment of the investigational results and calculations based on IS: 456-2000 code for flexural strength exhibited that the present provisions conservatively predicts the flexural strength and crack width of RC beams with WFS and 15% GGBS. It is suggested that 10% WFS can be used to make RC beam.Design/methodology/approachIn this present work, four RC beams made WFS and one RC beam made with natural aggregates. 15% GGBS is used as SCM for all RC beams. After casting of RC beams, the specimens were cured with wetted gunny bags for 28 days. After curing, RC beams like RCB0, RCB1, RCB2, RCB3 and RCB4 were tested under a four-point loading simply supported condition. An assessment of investigational results and calculations as per IS: 456-2000 code provisions has been made for flexural strength and crack width of RC beams with WFS and 15% GGBS. The crack pattern is also studied.FindingsFrom this experimental results, it is found that 10% WFS can be used for making RC beam. The RCB1 with 10% WFS shows better flexural performance than other RC beams. RC beams made with WFS show lesser number of cracks than referral beam–RCB0. IS: 456-2000 code provisions can be safely used to predict the moment capacity and crack width of RC beams with WFS and 15% GGBS.Originality/valueBy utilization of WFS, the dumping of waste and environmental pollution can be reduced. By experimental investigation, it is suggested that 10% WFS can be used to make RC structural members for low cost housing projects.

A novel inter-story drift limit proposal for TBEC2018 and fragility prognosis with TSC2007

The basic purpose of this paper is to investigate and propose a novel inter-story drift limits for the current Turkish Seismic Code to get easy structural assessment by using software. For this aim, numerical analysis was performed by modeling two types of RC frame structures. One of them is 5 stories, the other of them is 7 stories. Two different concrete classes, C20 and C25, were considered and three tension reinforcement ratios were considered for analysis. Tension reinforcement ratios were determined by half of the compressive reinforcement, equal to compressive reinforcement and double the compressive reinforcement ratio. Incremental dynamic analyses (IDA) were performed on these buildings. In this study to execute IDA, eleven seismic acceleration benchmark records were multiplied with various scaling factors from 0.2 to 1.0. Maximum base shear and corresponding roof displacement responses obtained from IDA curves were generated according to these responses. IDA curves were compared with each other by deriving fragility graphs. According to results, proposed limits for the current Turkish seismic code (TBEC-2018) provide, 0.6%, 2.4% and 3.3% respectively for MN, GV and GC, rather safe limits compared to drift limits presented in the foredate seismic code (TSC-2007).

Fire Resistance Assessment of Reinforced Concrete Slabs According to the Eurocodes

Reinforced concrete slabs are sensitive structural concrete elements to the effects of fire. This paper investigates the fire resistance of reinforced concrete slabs exposed to a standard fire using the simplified calculation mehods in the Eurocodes. The effects of tension reinforcement ratio, concrete cover, and concrete strength on the fire resistance of reinforced concrete slabs are assessed. The results show that the fire resistance of reinforced concrete slabs increases as the tension reinforcement ratio increases. The increase in concrete cover also improves the fire resistance of slabs, but up to a certain point where the decrease in the effective depth of cross-section becomes significant, the fire resistance of reinforced concrete slabs will be reduced. Meanwhile, high concrete strength slightly improves the fire resistance of reinforced concrete slabs.

INCREMENTAL DYNAMIC ANALYSIS OF MID-RISE RC BUILDINGS TO ASSESS EFFECT OF CONCRETE STRENGTH AND TENSION REINFORCEMENT RATIO IN BEAM

IDA is a parametric analysis method that has used commonly in several different forms to assess the structural performance under seismic loadings. This paper focuses on the effect of tension reinforcement ratio and concrete strength to performance of reinforced concrete (RC) structures. For numerical analysis, two RC frame type structures were selected. One of them is 5 stories other of them is 7 stories. Two different concrete class, C20 and C25, were considered and three tension reinforcement ratios were considered for analyses. Tension reinforcement ratios were determined half of the compressive reinforcement, equal to compressive reinforcement and double of compressive reinforcement ratio. Incremental dynamic analyses (IDA) were performed on these buildings. In this study to execute IDA, eleven seismic acceleration benchmark records were multiplied with various scaling factors from 0.2 to 1.2. Maximum base shear and corresponding roof displacement responses obtained from IDA curves were generated according to these responses. IDA curves were compared with each other by using suitable graphs. According to analyses results, increasing tension reinforcement of beam elements has not any effect on maximum roof displacement. Whereas, increasing of tension reinforcement decreased interstorey drift ratio. This result limited the damage due to decreased interstorey drift ratio.

Residual shear strength of reinforced concrete slender beams without transverse reinforcement after elevated temperatures

Forty-eight reinforced concrete (RC) beams without transverse reinforcement were tested at ambient and after exposure to high temperatures. Beams were heated to high steady-state temperatures of 350 °C, 550 °C, and 750 °C in a programmable closed electric furnace and loaded to failure after cooling down. In addition to exposure temperature, tension reinforcement percentage (ρ) and shear-span-to-depth ratio (a/d) were kept as the variables. In the beams tested at ambient and after the elevated temperature of 350 °C, beam action was dominant, and diagonal tension failure was the observed mode of failure. When beams were exposed to 550 °C and 750 °C, beam action almost vanished, and the beams failed due to the failure of a compression strut joining the loading point and the support. After exposure to high temperatures, shear strength loss observed in beams with a lower tension reinforcement ratio was found to be more significant. Whereas, change in a/d ratio had an insignificant influence on the shear strength loss of the beams. An increase in temperature resulted in the decrease of the beams stiffness and increased the deflection corresponding to the ultimate load. An empirical model was also developed from the data of the present study for the prediction of shear strength of RC slender beams exposed to high temperatures.

Flexural performance of reinforced carbon nanofibers enhanced lightweight cementitious composite (CNF-LCC) beams

As a type of lightweight concrete, foam concrete is traditionally used for non-structural applications due to its poor mechanical properties. However, in recent years, there is a surge in interest in potential applications of foam concrete as structural components due to its low self-weight, homogenous foam bubble distribution, self-compacting, saving in raw materials, good thermal and acoustic insulation. The main challenge for foam concrete is to have high-performance pore walls to provide required mechanical properties, shrinkage resistance, and durability under reduced density. A new type of foam concrete termed as carbon nanofibers enhanced lightweight cementitious composite (CNF-LCC) was developed and reported to have excellent mechanical properties, bond strength with steel reinforcement, durability and shrinkage resistance compared with traditional foam concrete. In this paper, the flexural performance of 8 reinforced CNF-LCC beams was investigated. Test parameters included the amount of carbon nanofibers (CNFs), tension and compression reinforcement ratios, and steel link ratio. The flexural performance of reinforced CNF-LCC beams was comparable with that of normal weight concrete (NWC) and lightweight aggregate concrete (LWAC) and even exceeded traditional foam concrete. The usual reinforcement detailing for NWC beams can be equally employed on CNF-LCC beams. Incorporation of CNFs produced varying degrees of improvement on flexural response especially ductility of beams. Finally, predictions from standard codes and the proposed model agreed well with the test results.

Static and Dynamic Stiffness of Reinforced Concrete Beams Strengthened with Externally Bonded CFRP Strips.

This paper presents experimental investigations of reinforced concrete (RC) beams flexurally strengthened with carbon fiber reinforced polymer (CFRP) strips. Seven 3300 mm × 250 mm × 150 mm beams of the same design, with the tension reinforcement ratio of 1.01%, were tested. The beams differed in the way they were strengthened: one of the beams was the reference, two beams were passively strengthened as precracked (series B-I), two beams were passively strengthened as unprecracked (series B-II) and two beams were actively strengthened as unprecracked (series B-III). Moreover, the strengthening parameters differed between the particular series. The parameters were: CFRP strip cross-sectional areas (series B-I, B-II) or prestressing forces (series B-III). The beams were statically loaded, up to the assumed force value, in the three-point bending test and deflections at midspan were registered. After unloading the beams were suspended on flexible ropes (the free-free beam system) and their eigenfrequencies were measured using operational modal analysis (OMA). The static measurements (deflections) and the dynamic measurements (eigenfrequencies) were conducted for the adopted loading steps until failure. Static stiffnesses and dynamic stiffnesses were calculated on the basis of respectively the deflections and the eigenfrequencies. The qualitative and quantitative differences between the parameters are described.

Experimental and numerical study on concrete beams reinforced with Basalt FRP bars under static and impact loads

The application of fiber-reinforced-polymer (FRP) bars to reinforce concrete structures could mitigate the corrosion-induced damage of steel reinforcements. No study has been reported in open literature on flexure-critical or shear-critical concrete beams reinforced with Basalt FRP (BFRP) bars under impact loads. In this study, six BFRP bars reinforced concrete beams were tested under quasi-static and impact loads. The test results showed the flexure-critical beams experienced the failure mode changing from flexure-governed under quasi-static loads to flexure-shear combined under impact loads. The shear-critical beams still failed in diagonal shear under impact loads, but experienced severer concrete spalling and more critical diagonal cracks on both sides of the beams. The impact performance of concrete beams with higher strength concrete may not be necessarily superior to that of beams with normal strength concrete due to the increased brittleness. Moreover, a numerical model of the tested beams under impact loads was developed and calibrated in LS-DYNA. Numerical results showed increasing tension reinforcement ratio could change the failure mode from flexure-governed to flexure-shear combined along with the reduced maximum midspan deflection. The BFRP bars reinforced concrete beams had comparable impact resistant performance with the conventional steel reinforced concrete beams