Tension Reinforcement Research Articles

On the ductility of RC beam section: A revision and up to date of conclusions

In the context of reinforced concrete (RC) structures, standards aim to relate the ductility of these structures to the ductility of the steels used in their construction. Among other requirements, EC8 requires the use of special ductility steels to achieve high ductility in structures. After reviewing the relevant literature, this study aims to evaluate the impact of various parameters on the ductility at the cross-section level of RC elements subjected to bending. The study concludes that there is no consensus on the assessment of ductility, nor a standardized framework for the various alternatives. Additionally: i) Some contradictions exist regarding the impact of fundamental parameters on the assessment of ductility; ii) A one-size-fits-all methodology is impractical given the diverse factors influencing ductility in RC elements. It is proposed to consider the ductility of RC element sections as a function of the mechanical ratio of tensioned reinforcement. A proposal is also made to enhance the ductility of cross-sections without significantly increasing their strength: by increasing the width of the section while keeping other parameters unchanged.

Bending Performance of Reinforced Concrete Beams with Rubber as Form of Fiber from Waste Tires

An investigation was conducted to assess the efficacy of using waste rubber as a substitute for a portion of an aggregate to enhance concrete’s sustainability. For the purpose of accomplishing this objective, a total of 12 specimens were constructed and then subjected to a series of tests to investigate their bending behavior. The samples were constructed with the following dimensions: 1000 mm length and a 100 mm by 150 mm cross-sectional area. A few factors were selected, including the impacts of the longitudinal reinforcement ratio and the waste rubber ratio. Based on the volume of aggregates, rubber replacement rates of 0%, 5%, 10%, and 15% were investigated in this study. To assess the beam bending behavior, the stirrup width and spacing were kept constant at ∅6/10. The longitudinal reinforcement was composed of three diameters: ∅6 at the top (for all beams) and ∅8, ∅10, and ∅12 at the bottom. The experimental results demonstrated that the effects of varying amounts of waste rubber and tension reinforcement on the bending and cracking of reinforced concrete beams (RCBs) were varied. The findings indicate that the incorporation of waste rubber into concrete results in a reduction in both the load-carrying capacity and the level of deformation of the material. Additionally, it was shown that as the amount of waste rubber in the RCB increased, the energy absorption capacity and ultimate load decreased. There was a reduction in energy dissipation of 53.71%, 51.69%, and 40.55% for ∅8 when longitudinal reinforcement was applied at 5%, 10%, and 15% replacement, respectively. Additionally, there were reductions of 25.35%, 9.31%, and 58.15% for ∅10, and 38.69%, 57.79%, and 62.44% for ∅12, respectively.

Innovative robotic-woven willow-clay-composite ceiling elements

Abstract The construction sector contributes 36% to global final energy use and 39% to energy-related CO2 emissions. Consequently, it is imperative to focus on quantifying and reducing environmental impacts e.g., via renewable building materials. The combination of fast-growing willow as tension reinforcement for regionally available and compression bearing clay seems a promising approach. The new attempt is based on the idea of full circularity, as the willow clay composite modules are in the first loop dismountable and can be rearranged and reused for another life cycle. When the composite material comes to its end-of-life, the materials can be theoretically fully recovered. To assess the environmental sustainability of such an innovative composite structure for the first time, a simplified cradle to grave Life Cycle Assessment is performed. The investigation is based on experimental data of the 1 to 1 scale robotically woven willow-clay-composite ceiling demonstrator. First results reveal hot spots, especially in the supply chain of the prototype production process but compared to conventional steel concrete ceiling, the innovative biobased composite is capable to function as a CO2 sink over the entire life cycle. In addition, the resource problem of timber could be circumvented accordingly.

The Consequence of the Involvement of Flexural, Compression, and Punching Reinforcement Upon Punching Strength

Flat slabs have an important role in concrete buildings due to their architectural flexibility and speed of construction. Punching shear is one of the most important phenomena to be considered during the design of reinforced concrete flat slabs, as this type of failure is brittle and does not predict previously raised alarms before failure. The main factors that affect punching strength in concrete are compressive strength, flexural reinforcement, and punching reinforcement in the form of stirrups, shear studs, or other shapes. This paper is part of a research program operated at the reinforced concrete laboratory of the Faculty of Engineering, Cairo University, to evaluate the contribution of horizontal flexural reinforcement, horizontal compression reinforcement, and vertical punching reinforcement on the punching strength of reinforced concrete flat slabs. In this research, fifteen half-scale specimens are cast and tested. The specimens had dimensions of 1100×1100 mm and a total thickness of 120 mm. All specimens were connected to a square column of dimensions 150×150 mm and loaded at the four corners with a supported span of 1000 mm. The main parameters considered in this research included spacing between stirrups, width of the stirrups, number of stirrup branches, ratio of the compression reinforcement, and ratio of the tension reinforcement. During testing, ultimate capacity, steel strain, cracking pattern, and deformation were recorded. The experimental results were analyzed and compared against values estimated from different international design codes. Doi: 10.28991/CEJ-2024-010-09-014 Full Text: PDF

Seismic analysis of geosynthetic-reinforced soil walls in tiered configuration

Research on geosynthetic-reinforced soil (GRS) walls in tiered configurations is increasing gaining attention, with numerical methods being predominantly used in the past. In recent years, there has been a growing trend in conducting shaking table tests to further explore this area. However, traditional limit equilibrium (LE) methods are more preferred for design purposes. This study utilized a modified top-down approach, which is based on LE and pseudo-static methods to investigate the horizontal seismic force on the distribution of required tension along each reinforcement layer. The approach is initially extended from static analysis to seismic analysis for multitiered GRS walls. Parametric analyses are conducted to study the impacts that horizontal seismic coefficient, reinforcement length and spacing, internal friction angle of soil, height ratio of upper/lower tier, offset distance have on the internal stability of two-tiered GRS walls. Meanwhile, influences of wall batter and number of tiers on the critical offset distance for different seismic coefficients are assessed. Results indicate that the internal stability differs between the upper and lower tiers under seismic conditions, particularly with higher seismic forces, where the lower tier requires greater reinforcement tension to enhance its stability. Additionally, the critical offset distance grows with the increase in seismic coefficient, and it is sensitive to the internal friction angle of soil and the height ratio.

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.

Experimental flexural investigation of RC beams with impeded steel truss using smooth steel angels

This paper emphasizes on testing the flexural capacity of Hybrid Steel Truss Reinforced Concrete Beam (HSTRCB), where a prefabricated steel truss is embedded into concrete beam instead of conventional rebars, forming a composite section. Five doubly reinforced concrete beams were designed, casted, experimentally tested and analyzed to investigate the flexural behavior of HSTRCB, in comparison to ordinary reinforced concrete beam. All beams were designed according to ACI 318, having same flexural capacity. First beam is ordinary reinforced concrete beam while the other four HSTRCB were designed having identical smooth steel angles, as compression and tension reinforcement, with different shear reinforcement alignment, and spacing. Different smooth truss typology were used as reinforced rebar replacement in the RC beams to determine the significant truss configuration that has highest flexural behaviour. The results showed that HSTRCB improves cracking moment, stiffness, energy absorption and effective cracked moment of inertia during the entire loading stages.

The development and performance evaluation of diagonal tension cracks control devices

ABSTRACT The cause of diagonal tension cracks is the drying shrinkage of the initial concrete, which causes them to appear at the corners of square openings, which are the most vulnerable areas to stress. Looking specifically at the cause from a structural aspect, the concentrated stress exceeds the tensile strength of the concrete, causing cracks to occur at the corners. Typically, diagonal tension reinforcement bars are arranged to prevent diagonal tension cracks, however, they have often failed to be practical solutions because they do not entirely prevent the continued occurrence of cracks. Consequently, the present study developed diagonal tension cracks control devices that are capable of preventing diagonal tension cracks. Next, comparative experiments on existing diagonal tension reinforcement bars with respect to drying shrinkage were conducted to verify the utility of the diagonal tension crack reinforcement materials through performance evaluation. According to the results, the maximum elastic strain at the top and bottom opening edges was 29.2% and 35.8%, respectively, which was a large reduction compared to the 6.7% and 4.9% of the existing diagonal tension reinforcement. Considering the above points, it is expected that the developed control device will be very practical in terms of industry.

Experimental study of moment redistribution in continuous concrete beams prestressed with unbonded tendons

AbstractThe moment redistribution in a continuous prestressed concrete beam occurs as a result of a change in the rigidity of a beam and formation of plastic hinges when approaching the failure. Rotation capacity is required to allow for moment redistribution. Four continuous two‐span concrete beams prestressed with unbonded tendons were built and loaded up to failure at the laboratory of Civil Engineering in Tampere University. The test beams had different reinforcement ratios in the support area when the degree of prestressing and amount of tension reinforcement in the midspans were kept constant. All test beams were loaded by bending, but one test beam had torsion load in addition to bending. The degree of bending moment redistribution was defined by using nonlinear analysis and equations from the European standard and ACI318, as well as the test results. Moment redistribution clearly occurred on all test beams, and the beams had a high level of deformability.

Optimum Design of Reinforced Concrete Beams with Large Opening Using Neural Network Algorithm

It is quite rare to find researches in the literature connecting neural networks to design challenges in civil engineering, particularly with regard to beam with large openings. Therefore, to ascertain the best cost design for such a beam, an optimization technique is developed, written using MATLAB functions, and verified in this study. Because of the efficiency and dependability of the iterative Particle Swarm Optimization (PSO) process, the ACI 318-19 code method is adopted via this algorithm. Using four beam design (decision) variables, which are: beam width b, longitudinal tension reinforcement area As, longitudinal compression reinforcement area A’s, and vertical shear reinforcement area Av; the objective is to minimize the overall beam cost function. The constraints for each of the 60 randomly chosen particles are handled using the self-adaptive penalty function technique, which is applied in all the 100 iterations for each of the four proposed beam design case studies with identical openings. For the developed method, completing all iterations serves as a stopping criterion. Comparative studies are conducted to demonstrate how the compressive strength of concrete and the live load scheme affect the optimal overall beam cost and the associated design variables. The relations between cost of beams and the four design variables, which are presented through graphs and tables, indicate that the beam’s cost is significantly impacted by the loading condition. This is shown by increasing the cost of beam B1, with no sustained live loads, from 722 US dollars to 984 US dollars for beam B4, which has concentrated and distributed sustained live loads. Future research is advised to include modern strengthening techniques for beams with openings, and apply this research to a PSO algorithm with several objectives.

Shear Capacity of RC Beam with Opening Strengthened Using CFRP Sheet and Plate

This paper investigates the use of carbon fibre-reinforced polymer (CFRP) sheets and plates for the bi-directional reinforcement of reinforced concrete beamswith transverse single and double symmetrical openings. The dimensions of the under-reinforced specimens are 1900mm in length, 150mm in width, and 300mm in height, with 3H12 tension reinforcement, 2H6 compression reinforcement, and R6-300 stirrups. This study aims to compare the maximal shear capacity of each CFRP configuration to that of conventional beams andevaluate the deflection profiles, failure modes, strain distribution, and crack patterns under shear loads. The beams are created using in-situ casting, and the openings are treated using post-drilling techniques to simulate real-world procedures. The beam specimens are subjected to a four-point stress test following the application of Sikadur-330 and CFRP. The principal findings indicate that the application of CFRP sheets increases the ultimate shear strength compared to conventional beams with openings, whereas the application of CFRP plates has the opposite effect. Nevertheless, the control beam with no openings has the greatest ultimate shear capacity. In addition, the sheet reinforced CFRP specimens exhibit less deflection than the control beam and conventional beams. The use of both CFRP sheets and plates aids in the transition from shear failure to flexural failure.

Simulation and design model for reinforced concrete slabs with lacing systems

Lacing reinforcement plays a critical role in the design and performance of reinforced concrete (RC) slabs by distributing the applied loads more evenly across the slab, ensuring that no specific area of the slab is overloaded. In this study, nine slabs, divided into three groups according to the investigated parameters, were meticulously designed and evaluated to study the interplay between the lacing reinforcement and other key parameters. Each slab was crafted for simple support and was subjected to both static and repeated two-point load tests. The lacing reinforcement had an angle of 45° with various tension and lacing steel. The repeated-tested specimens with lacing reinforcement experienced smaller ductility than those of similar static-tested specimens, where the reduction in ductility factor ranged between 8.4% and 22.3% for all specimens. Additionally, the tested slabs were analyzed numerically using the ABAQUS software package. The validated FE test program was used to study the effect of varying the lacing reinforcement ratio, the compressive strength of concrete, and the material types of the tension and lacing reinforcements. The lacing reinforcement becomes more effective in increasing the slab capacity when using the higher compressive strength of concrete.

Case Study on Instrumenting and Monitoring Geosynthetic-Reinforced Pile-Supported Mechanically Stabilized Earth Wall Built over Soft Soil

This paper presents a case study on instrumenting, monitoring, and finite element modeling (FEM) of geosynthetic-reinforced pile-supported (GRPS) mechanically stabilized earth (MSE) walls. The GRPS-MSE wall was monitored using various instruments such as piezometers, earth pressure cells, shape-acceleration arrays (SAAs), and strain gauges. The performance criteria included efficacy, stress concentration ratio (SCR), differential settlement, and reinforcement tension. Collected data, such as excess pore-water pressures, contact pressures on pile and soft soil, differential settlements, and lateral displacement of MSE wall, were analyzed thoroughly. A 3D FEM was also developed to simulate the GRPS MSE wall, and the results are in good agreement with field data. The results demonstrated significant load transfer from soil to piles as a result of soil arching, yielding 30–32 SCR. The field efficacy was measured at 37.69 %, while the FEM efficacy was estimated as 42.4. Strains in geogrids within the geosynthetic-reinforced load transfer platform (GLTP) system were under 1%, less than the 5% maximum recommended by FHWA. The maximum differential settlement measured between pile cap and soft soil from SAAs is 7.1 mm, while it is estimated to be 8.3 mm from FEM. The MSE wall exhibited low lateral displacement (<25 mm), indicating enhanced stability because of GLTP. The comparison between five analytical GLTP design methods showed that the CUR226 methods gave the closest results to field measurements and FEM results. This study offers crucial insights into leveraging GLTP and MSE walls in highway construction.

Unified two-way shear model for steel and FRP-RC slabs: Evaluation and reliability calibration

This study introduces a unified two-way (punching) shear design model for concrete reinforced with slabs steel- and FRP bars. The unified model modifies the ACI 318-19 punching shear model to account for the axial stiffness of the tension reinforcement by providing a new modification term (ρ Ereft./Ec)0.26, representing the reinforcing ratio multiplied by the elastic modular ratio of longitudinal bars to concrete. The unified punching shear model has been evaluated over two experimental datasets: FRP-RC slabs (145 specimens) and steel-RC slabs (390 specimens). A comparative assessment between the ACI 440.11-22, CSA S806, JSCE, and the proposed models to test their generalization abilities for slabs reinforced with both types of reinforcement. The assessment indicated a similar performance of the proposed model to the CSA S806 and the JSCE models in terms of statistical measures. The ACI 440.11–22 showed a high average strength ratio (Vexp./Vpred.) of 1.83. However, the ACI and the CSA models showed reduction in the conservatism at high reinforcement axial stiffness. In addition, reliability analysis using Monte Carlo simulation indicated that the unified punching shear model provides a satisfactory safety level with a reliability index between 3.5 and 4.0 for both steel and FRP-RC slabs.

Flexural-shear strengthening of reinforced concrete T-beams subjected to asymmetric loading using CFRP system combined by NSM strips and U-wraps

This paper presents a developed three-dimensional (3D) finite element model (FEM) of flexural and shearstrengthening of reinforced concrete (RC) T-beams using a CFRP (Carbon Fiber-Reinforced Polymer) system combined by near-surface mounted (NSM) strips and U-wraps subjected by asymmetric loading. The 3D FEM was verified by experimental results. Concrete was simulated by a total-strain-based rotating smeared crack model. NSM CFRP strips and CFRP U-wrap sheets were modeled as shell elements. Steel reinforcement and NSM CFRP strips were embedded in concrete, corresponding to a perfect bond. U-wrap sheets were modeled as a shell element and bonded to the concrete surface using an interface element, considering appropriate bond properties. Four RC T-beams from an experimental work were analyzed, and predictions of the applied load-displacement curve and failure mode were presented to demonstrate the accuracy of the developed finiteelement analysis. It is shown that the finite element results of T-beams agree well with the experimental behavior in terms of applied load versus displacement and failure mode. Moreover, a parametric study was conducted to examine the influence of some design-oriented parameters such as concrete compressive strength, amount of longitudinal tension reinforcement, amount of stirrups, multiple layers of externally bonded (EXB) CFRP sheets, and flange width.

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.

Cyclic behavior of self-centering RCFST column to beam joints with prefabricated connectors

This paper presents the cyclic behavior of reinforced concrete-filled steel tube (RCFST) column to beam joint with prefabricated connectors. The cyclic performance of four specimens was investigated to focus on the hysteretic behavior, reinforcement tension, residual deformation, and strain distribution of joints. The equivalent viscous damping coefficients (ξeq) corresponding to the four specimens range from 0.049 to 0.087 at the yield point. And the final residual drift ratio of the specimens ranged from 3.6% to 12.9%. The tested column-beam joint specimens had good hysteretic behavior, energy dissipation, and self-centering ability. The PT steel bars without hollow channel or weakened treatment enhanced the self-centering ability and workability of joints. The finite element models were developed to verify the main mechanical properties of the self-centering RCFST column to beam joint. The average of KE/ KFEA, Mc,y/ My,FEA and Mc,p/ Mp,FEA were 0.89, 0.98, and 1.03, respectively. The FEA models could predict mechanical properties of the joints with high accuracy.

External precast concrete nib beam-to-column connection under elevated temperatures: Experimental and finite element analysis

The precast concrete nib is one of the most widely used beam-to-column connections to address the architectural drawback of the ordinary precast concrete corbel. However, precast concrete nib beam-to-column connections are not classified as fully rigid or pin but exhibit semirigid properties. Semirigid connections are at risk of deflection at lower loads and cracking during early fire events. In this study, full-scale fire tests were carried out to determine the thermal and structural behaviour of the external monolithic and precast concrete nib beam-to-column connections subjected to 120 min standard cellulose fires. A finite element simulation using ANSYS validated the experimental results based on the internal temperature distributions, load–deflection curves, and stress visualization. Results show that the tension reinforcement of the concrete nib specimen at high temperature was below the critical temperature of 300 °C during the 120 min of heating, compared to the monolithic specimen, which reached the critical temperature of 300 °C at 105 min. The crack patterns and failure modes of monolithic and precast concrete nib specimens at high temperatures were more visible than at ambient temperature. Based on the ductility factor and Monforton’s fixity factor, the concrete nib specimen at high temperatures was categorized as structures with limited ductility and classified in Zone I (pin connection), respectively. This study concluded that external precast concrete nib beam-to-column connections were more vulnerable at high temperatures than monolithic connections.

RETRACTED: Application of waste ceramic powder as a cement replacement in reinforced concrete beams toward sustainable usage in construction

The main purpose of this study was to investigate the flexural behavior of reinforced concrete beams (RCBs) containing waste ceramic powder (CP) as partial replacement of cement. For this purpose, flexural tests were carried out using various amounts of mixing ratios. By determining the amount of CP utilized in the optimum ratios, it was aimed both to make predictions for design engineers and to show its beneficial effect on the environment by recycling the waste material. For this purpose, twelve specimens were produced and verified to monitor the flexural behavior. The longitudinal reinforcements percentage (0.77%, 1.21%, and 1.74%) and CP percentage (0%, 10%, 20%, and 30%) were chosen as the parameters. CP could be effectively used up to 10% of cement as a replacement material. Increasing the CP percentage by more than 10% could considerably reduce the load-carrying capacity, ductility, and stiffness of RCBs, specifically when the longitudinal reinforcements percentage was high. In other words, as CP increased from 0% to 30%, the load-carrying capacity decreased between 0.4% and 27.5% compared with RCBs with the longitudinal tension reinforcements of 2ϕ8 without CP. However, reductions of 5.5–39.8% and 2.15–39.5% in the load-carrying capacity occurred respectively compared with RCBs with the longitudinal tension reinforcements of 2ϕ10 and 2ϕ12 without CP. The achieved longitudinal reinforcements percentage was close to the balanced ratio, while more than 10% CP cannot be used without any precautions for mixtures.