Ordinary Steel Bars Research Articles

Cyclic bond behavior and bond stress – slip model of steel strands in steel fiber reinforced concrete

To study the bond performance of steel strands in steel fiber reinforced concrete (SFRC), bonding tests under monotonic and cyclic loads were performed on the specimens with different steel fiber volume fractions (SFVFs), bond lengths, nominal diameters of steel strands and SFRC strengths. The results showed that the relative rotation between the steel strand and SFRC occurred when the steel strands were vertically pulled out from SFRC due to the smooth and continuous helical shape of the steel strands. For the specimens with the same parameters, the maximum bond stress under cyclic load decreased by 1.67–22.88 % than that under monotonic load. The maximum bond stress under cyclic load increased with the increasing SFVFs or SFRC strength. Notably, the maximum bond stress under cyclic load also increased with the increasing bond length or diameter of steel strands, significantly different from that of ordinary ribbed steel bars and FRP bars. The cumulative energy dissipation (CED) of bond specimens increased with the diameter of steel strands and SFRC strength. Besides, the SFVFs had a positive effect on the CED, but simultaneously increasing diameter of steel strands would weaken the positive effect of SFVFs, and simultaneously increasing bond length had no obvious on the CED. Finally, a bond stress – slip model of steel strands in SFRC was established, suitable for calculating bond stress – slip curves under random and complicated loading schemes. By comparing the calculation and test results of bond stress – slip curves, it was proved that the proposed model had an acceptable accuracy and could describe the influence laws of SFVF, bond length, nominal diameter of steel strand and SFRC strength well.

Bending resistance mechanism of prestressed ultra-high performance concrete - reinforced concrete beam based on a full-scale experiment

Ultra-High Performance Concrete (UHPC) is a new type of engineering material with high compressive strength, high tensile strength, and high fracture toughness. Its bending failure mechanism is different from that of traditional concrete beams, which requires a new computational model to describe the bending failure phenomena of the prestressed ultra-high performance concrete - reinforced concrete (UHPC-RC) beam without web reinforcement. Therefore, this paper, through full-scale tests on a 30m prestressed UHPC-RC beam without web reinforcement, captures unique bending failure phenomena, including initial cracking, development of local cracks, and rupture of prestressed steel strands. Considering the tension-compression constitutive relationship of UHPC material, an innovative computational model for bending bearing capacity is proposed. Based on this model, a study on the minimum reinforcement ratio of full prestressed-ordinary steel bars is conducted. The results show that in the bending failure of the prestressed UHPC-RC beam without web reinforcement, excessive tensile strain of steel strands will occur at the local crack location. At this time, the structure does not satisfy the assumption of plane sections, and the introduction of the calculation model of the limit state of external prestressed tendons can effectively match this model, which is highly consistent with the experimental results. The minimum reinforcement ratio of full prestressed-ordinary steel bars is revised to the auxiliary reinforcement ratio of full prestressed-ordinary steel bars, quantifying the minimum reinforcement requirements of ordinary steel bars. The research results of this paper can provide reference for the next step of theoretical research.

Seismic response and failure mechanism of ordinary concrete and UHTCC short columns reinforced with negative Poisson's ratio steel bars

The replacement of ordinary steel bars by negative Poisson's ratio (NPR) steel bars to improve the seismic performance of short columns is investigated in this study. NPR steel bars is a new type of reinforcement with negative Poisson's ratio effect and high strength and ductility. In this paper, six short column members were designed. Among them, P-RC1 and P-UHTCC1 short columns were used as controls, and the remaining four specimens were reinforced by NPR steel bars. The failure mode, cracking pattern, hysteresis characteristics, plastic deformation capacity, shear strength, stiffness degradation and energy dissipation capacity of the specimens were investigated through lateral cyclic loading tests. The experimental results showed that the shear capacity of short concrete columns reinforced with NPR steel bars increased by 20.91%−22.64% and the cumulative energy dissipation capacity increased by 45.7%−63.3%. The short UHTCC columns reinforced with NPR steel bars showed an increase in shear capacity of 23.08%−35.48% and an increase in cumulative energy consumption capacity of 17.3%−28.5%. And the RC columns shear strength prediction model based on GB50010–2010 specification is relatively reasonable to be used for the evaluation of shear strength of short columns reinforced with NPR steel bars.

Seawater Corrosion Resistance of Duplex Stainless Steel and the Axial Compressive Stiffness of Its Reinforced Concrete Columns

In order to explore the corrosion resistance of duplex stainless steel under seawater corrosion and the compressive stiffness of its reinforced concrete columns, this study first performed seawater corrosion resistance tests on HRB400 ordinary steel rebar and S32205 duplex stainless steel rebar. The effect of the corrosion product film on the corrosion behavior was investigated through polarization curve tests and electrochemical impedance spectroscopy tests. The results showed that the corrosion rate of S32205 duplex stainless steel in a seawater environment was approximately 1/15 that of the HRB400 ordinary steel rebar. The anodic polarization curve of duplex stainless steel rebars exhibited a greater slope than that of carbon steel rebars. In the simulated seawater environment, the corrosion rate of these two kinds of steel bars showed different trends. The corrosion rate of ordinary steel bar HRB400 first decreased and then increased, while that of duplex stainless steel S2205 increased steadily. Furthermore, 18 short concrete columns reinforced with ordinary and duplex stainless steel rebars were subjected to the axial compression test and stiffness analysis; the stiffness of the short columns was calculated from the test data. The theoretical values agreed with the test values, with a stiffness calculation error of less than 5%.

Experimental investigation of innovative reinforcement method for two‐way concrete slabs using perforated steel plates

AbstractImprovement of the bonding and interaction between concrete and steel is crucial to achieving an optimal reinforced concrete member. The proposed technique in this paper is using perforated steel plates (PSPs) to reinforce two‐way concrete slabs. In this method, ordinary steel bar reinforcements in the tension region of the concrete slabs were replaced by PSPs. Concrete slabs reinforced with PSPs enhance structural characteristics with respect to concrete slabs reinforced with ordinary reinforcement (OR) due to the higher lateral stiffness of PSPs, the better confinement of concrete within the holes of PSPs, the biaxial performance of the steel in the tension region, and the efficient load transmission mechanism between the steel and concrete. In this paper, a comprehensive experimental investigation was conducted on two‐way concrete slabs reinforced with PSPs and ordinary steel bars. The behavior of PSPs slabs was evaluated in comparison with OR slabs in terms of failure types, ductility, energy absorption, stiffness, ultimate load, cracking load, and force transmission mechanism. Findings revealed that the PSPs slabs have higher ductility, energy absorption, and ultimate strength compared to the OR slabs.

Experimental and theoretical investigation of the structural behavior of reinforced glulam wooden members by NSM steel bars and shear reinforcement CFRP sheet

Abstract Reinforcing the wooden structural members is considered as a challenging matter to overcome the drawbacks of using wood in the construction field. The current investigation, therefore, presents an attempt to evaluate the effectiveness of utilizing steel bars as reinforcements in glulam timber beams using the near-surface-mounted (NSM) technique in conjunction with carbon fiber-reinforced polymer (CFRP) sheet wraps. A series of flexural testing was carried out until failure for both reinforced and unreinforced glulam members in a simple support system. Eleven specimens were examined in two groups to compare them with the control beam. Five reinforced glulam (RG) beams of the first group were reinforced with different schemes at tension and compression zones using the same bar size. The other five specimens of the second group were reinforced with shear reinforcement using fully wrapped strips made of CFRP sheet in addition to the same flexural reinforcement schemes as the first group. Each glulam beam has a span of 1.35 m and a rectangular section sized 85 mm × 175 mm. Based on experimental outcomes, theoretic modeling was provided to estimate the ultimate load capacity and bending rigidity of reinforcing glulam members. Though several theoretical predictions of flexural capacity were overstated when compared to experimental predictions, these disparities were frequently about 10%, confirming that the proposed theoretical model was accurate, and the mean of ultimate loading capacity and deflection between experimental and theoretical results were 1.01 and 1.09, respectively. Experimental results presented show that the RG beams performed much better than the unreinforced reference beams in terms of structural behavior, with improvements in ultimate load capacity ranging from 16 to 49%. On the other hand, the shear reinforcement for RG members slightly improved flexural performance, and the ultimate load capacity increased by 2–7%. Therefore, it was concluded that the NSM techniques using ordinary steel bars were effective ways in strengthening the glulam members in terms of flexural stiffness with increasing ultimate load capacity.

Deduction of the bond law from test on short RC tie in service conditions

AbstractBond between ordinary steel bars and concrete plays a fundamental role in the behavior of the reinforced concrete. It is associated to the slip between steel and surrounding concrete and determines the variation in the steel and concrete stresses of cracked RC members. The need to formulate simple constitutive bond laws has led the international standards, such as fib Model Code 2010, to adopt an average bond stress versus slip relationship obtained from an extensive experimental campaign based on pull‐out tests. However, in pull‐out tests bond is substantially influenced by the state of stress, deformation and cracking of the concrete. Moreover, in‐service conditions of RC members, in order to study the cracking behavior or the tension stiffening, an ascending distribution of the bond stress is usually considered as it corresponds to an ascending distribution of the slip from the zero slip section to the cracked section and in the literature the bond law is applied as it is. In particular, at the cracked section, the bond stress is maximum. But, this distribution of the bond stress is not confirmed by the experimental results available in the literature concerning the behavior of an RC tie with a length equal to the crack spacing, where close to the cracked sections a descending distribution of the bond stress is observed while the distribution of the slip remains ascending, with null bond stress at the cracked section. The modeling proposed here does not claim to be exhaustive due to the limited albeit accurate experimental data. However, it does indicate the opportunity to abandon bond laws based on experimental works that do not represent the real situation or are far from it.

Stochastic analysis for bending capacity of precast prestressed concrete bridge piers using Monte-Carlo simulation and gradient boosted regression trees algorithm

The use of precast prestressed concrete bridge piers is rapidly evolving and widely applied. Nevertheless, the probabilistic behavior of the bending performance of precast prestressed concrete bridge piers has often been overlooked. This study aims to address this issue by utilizing actual precast bridge piers as the engineering context. Through the implementation of the Monte-Carlo simulation and Gradient Boosted Regression Trees (GBRT) algorithm, the stochastic distribution of the bending performance and their critical factors are identified. The results show that the normal distribution is the most suitable for the random distribution of bending performance indicators. The variability of the elastic modulus of ordinary steel bars, initial strain of prestressed steel hinge wires, and constant load axial force has little effect on the bending moment performance, while the yield stress of ordinary steel bars, elastic modulus of concrete, compressive strength of unrestrained concrete, and elastic modulus of prestressed steel hinge wires have a greater impact on the bending performance. Additionally, the compressive strength of unrestrained concrete has a significant influence on the equivalent bending moment of the cross-section that concerns designers.

Corrosion products of low-alloy steel bars and their induction of cracking in seawater sea-sand concrete cover

The integration of low-alloy steel reinforcement (LS) with seawater sea-sand concrete (SSC) offers an opportunity for marine infrastructure construction that utilizes local resources, such as seawater and sea-sand, while ensuring exceptional durability of structures in challenging environments. However, the cracking of the concrete cover resulting from rebar corrosion remains the primary factor contributing to the deterioration of reinforced-concrete structures exposed to marine environments. In this study, an external current was applied to accelerate the corrosion process of both LS and ordinary steel bars (OS), which were embedded in SSC that was shallowly buried in a wet-salt sand environment. To accurately determine the timing and location of SSC cover cracking, Digital Image Correlation (DIC) technology was utilized. Microscopic analysis was conducted to examine the morphology, phase composition, and content of each component of the corrosion products. Then, the expansion coefficients of the corrosion products of the rebars embedded in SSC with different water–binder ratios were determined. The results indicated that the primary corrosion products formed on OS are α-FeOOH, β-FeOOH, γ-FeOOH, Fe2O3, and Fe3O4, which form a porous structure. In comparison, corrosion products of LS are fundamentally similar to those of OS but include Cr2O3, producing a compact rust layer for better steel protection. Furthermore, the corrosion products of LS exhibit a lower expansion coefficient compared to those of OS in SSC with an identical water–binder ratio. Finally, the cracking time of the SSC cover, as determined through DIC, was validated through the use of a conventional prediction model.

Exploration And Research on The Durability of FRP Composite Materials

Concrete cracking caused by steel corrosion is the main form of concrete structure deterioration at present. In order to solve the problem of steel corrosion, people begin to seek to replace steel with corrosion-resistant materials. Fiber reinforced polymer (FRP) has the advantages of high strength to mass ratio, good fatigue resistance, simple construction, corrosion resistance, etc., and has been widely used in engineering in recent years. In this paper, it analyzes the research status of FRP composites and introduces the properties of different kinds of FRP composites in detail. Then, by comparing with ordinary steel bar, the advantages of steel bar containing FRP material are highlighted. Subsequently, the durability of FRP composite materials in corrosion environment is studied. Finally, this paper introduces the practical application of FRP composites in engineering. The results are helpful to popularize the application of FRP composites in practical engineering.

Study on flexural behavior of concrete beams reinforced with hybrid high-strength and high-toughness (HSHT) and ordinary steel bars

To study the flexural behavior of high-strength and high-toughness (HSHT) reinforced concrete beams with negative Poisson’s ratio and special spiral grooves on the surface, fifteen beams of 250 mm × 450 mm × 3200 mm were designed and manufactured to conduct bending tests. The effects of different parameters, including the reinforcement ratio, compressive strength of concrete, loading mode, the number of HSHT steel bars in hybrid reinforcement, and longitudinal steel bars type, were studied on failure modes, crack patterns, flexural stiffness, flexural strength, ductility, and energy absorption capacity. The load versus mid-span deflection curves for concrete beams reinforced with HSHT steel bars can be divided into five stages. The concrete beams reinforced with HSHT steel bars can also bear higher residual strength (approximately 0.9 Fp) and exhibit superior crack width control ability. The peak load increases by a maximum of 22.9 % with the reinforcement ratio of HSHT steel bars increasing from 0.86 % to 1.08 %. Hybrid reinforcement can improve the service performance of concrete beams, take full advantage of HSHT steel bars, and increase the energy absorption capacity of beams. Based on strain analysis of cross-section, the flexural strength model of concrete beams reinforced with hybrid reinforcement was proposed by considering the ultimate compression strain. The calculation results show that the proposed model can accurately calculate the flexural strength of concrete beams reinforced with HSHT steel bars.

Bond Performance of Anti-Corrosion Bar Embedded in Ceramsite Concrete in Freeze–Thaw Cycles and Corrosive Environments

At present, basalt fiber-reinforced polymer (BFRP) bars and epoxy-coated steel reinforcing bars (ECRs) are very promising in ocean engineering. In this study, the bond strength degradation characteristics of BFRP bars, ECR, and ordinary steel bars (OSBs) embedded in ceramsite concrete (CC) were compared in a single-corrosive environment (acid, salt, and alkaline salt, respectively) coupled with freeze–thaw (FT) cycles (0, 15, or 30); a total of 111 specimens were designed. In the three corrosive environments, the BFRP-bar-CC specimens and OSB-CC specimens all failed to pull out, while the ECR-CC specimens showed splitting failure. When corrosive and FT cycles acted together, the failure modes of BFRP-bar-CC specimens and ECR-CC specimens did not change. However, when the FT cycles increased from 15 to 30, the type of failure for the OSB-CC specimens changed from pullout failure to splitting failure. In addition, the bonding strength of the three kinds of bars decayed most rapidly in an acid environment. When 30 FT cycles were applied, the bond strength of ECR-CC specimens and OSB-CC specimens decreased most rapidly in the acid environment, by 9.12% and 18.62%, respectively. However, the bond strength of BFRP-bar-CC decreased most rapidly, by 17.2%, in an alkaline salt environment.

Bond performance between recycled concrete and steel bar after high temperature

Abstract To investigate the influence of high temperatures on the bond performance of recycled concrete and steel bar, this article considers the influence of different concrete types (ordinary concrete and recycled concrete) and different temperatures (20, 100, 150, 200, 250, and 300°C) on the concrete compressive strength and the bond performance of concrete and steel bar. On this basis, the calculation formula of bond strength and bond slip between concrete and steel bar after the high temperature is established. The test results show that the concrete compressive strength presents a downward trend with the increase in temperature; the compressive strength loss of recycled concrete is higher than that of ordinary concrete; when the temperature reached 300°C, the compressive strength loss of ordinary concrete is 24.4%, while that of recycled concrete is 41.6%. The bond strength of pull-out specimens decreases with the increase of temperature, while the bond slip increases with the increase of temperature; the bond strength between recycled concrete and steel bar is lower than that between ordinary concrete and steel bar, while the bond slip between recycled concrete and steel bar is higher than that between ordinary concrete and steel bar. This article can provide a theoretical basis for the application of recycled concrete in high-temperature environment.

Influencing Factor Analysis on Bond Behaviors of FRP Bars and Concrete

Fiber reinforced composite (FRP) bars have the advantages such as anti-corrosion, high strength and reducing the weight of components. Applying them to concrete structures instead of ordinary steel bars can improve the stability of the whole structures and enhance the corrosion resistance of the structure, therefore the application of components will expand. The bond behavior between FRP bars and concrete is an important indicator to show its working performance, hence, the researches of the bond behaviors are significance. This paper summarizes the research status of previous researches on the bond behaviors of FRP bars and concrete under different conditions. Firstly, the commonly used test methods for testing the bonding properties are introduced. Secondly, the main research results are analyzed and compared from three aspects: concrete type, FRP bar surface shape and surface treatment method, and environmental factors. Finally, the shortcomings of the existing research are expounded, and the feasible further research directions in the future are also proposed.

Experimental Study on Seismic Performance Improvement of Pile-Cap Joints in a Prestressed Concrete Solid Square Pile Using a Snap-In Mechanical Connection

ABSTRACT To improve the seismic performance of prestressed concrete solid square piles with a snap-in mechanical connection, effects of the prestressed tension control stress of PC steel rods, anchoring method and reinforcement ratio of hot-rolled steel bars on the seismic performance of the pile-cap joints in the prestressed concrete solid square piles using a snap-in mechanical connection were investigated in this article. Considering the above-mentioned effect factors, the quasi-static test was first carried out on the cap pile-cap joint specimens. Then, the seismic performance of the specimens was investigated. The results indicated that the yield load and ultimate load changed slightly, the displacement ductility increased, the stiffness decreased and the damage development rate slowed down as the prestressed tension control value decreased. When the prestressed tension control stress was reduced to 0.4 times of the standard value of tensile strength of the PC steel rods, the crack resistance moment could meet the requirements of construction and hoisting at the same time. In the process of pile cutting and anchoring, the 135° hook treatment on the end of the PC steel rods could reduce the strength degradation of the pile-cap joints during the loading process, improve the energy-dissipation capacity and slow down the damage development rate of the pile-cap joints. For the specimens with ordinary hot-rolled deformed steel bars added to the pile end, its ductility was improved, the horizontal bearing capacity, displacement ductility and energy dissipation capacity were all greatly improved, and the damage development rate was slowed down. However, the reinforcing ratio of the ordinary hot-rolled steel bars should be kept within a reasonable range. Finally, the improvement measures were proposed to improve the mechanical properties of the prestressed concrete solid square piles and pile-cap joints.

Analytical investigations of concrete beams reinforced with FRP bars under static loads

Fiber Reinforced Polymer (FRP) bars have appeared as a preferable alternative to ordinary steel bars in reinforced concrete (RC) members due to their higher ultimate tensile strength-to-weight ratio and corrosion resistance. The previous studies have mainly focused on laboratory tests and finite element modeling approaches for FRP-RC beams; however, only limited analytical studies have been conducted. Therefore, this study was designed to present analytical investigations of full-scale concrete beams longitudinally reinforced with Glass-Fiber Reinforced Polymer (GFRP) bars. The Strips Analysis Method (S-A-M) was used to implement the analytical investigations using stress–strain models for concrete and reinforcement. The beams, having the cross-sectional dimensions of 150 mm width × 200 mm height, were statically analyzed under different-point bending. The analytical results were verified with the results of experimentally tested GFRP-RC beams, and the outcomes showed excellent agreements. Also, the analytical method used in this study exhibited much efficiency and reliability compared with the traditional procedures used for the analysis of ordinary reinforced concrete members. A parametric study was, in addition, conducted to investigate the effects of concrete compressive strength, different-point bending, and scale of beams on the performance of GFRP-RC beams. It was found that the structural efficiency of GFRP-RC beams can be enhanced with the increase in concrete compressive strength and significantly influenced by the scale size of beams.

A comparative analysis of the chemical composition and compliance level to established standards of concrete reinforcement steel rods rolled in Nigeria

Nigeria is presently facing the challenges of collapsing buildings and bridges due to substandard materials used as reinforcement products. The increasing use of scraps as feedstock for the production of reinforcing steel bars by steel rolling mill companies has adversely affected the quality of rebars in Nigeria. This research study aimed to appraise the chemical properties of selected brands of steel rebars of Nigeria. Thirty selected brands of rebars were sourced from the six geopolitical zones in Nigeria, and their chemical compositions were analysed for level of compliance with five selected standards (SON, BSI, ASTM, AISI, ISO). The chemical composition test was performed using Optical Light Spectrometric methods. One way analysis of variance (ANOVA) test was performed using SPSS version 20 to examine whether significant differences exist or not in mean chemical composition for the different categories of selected steel rods. Statistical analysis shows a significant difference (P < 0.05) in chemical composition and compliance level between the different types of selected steel rods. The imported steel rods recorded the highest mean (μ = 101.4) in terms of chemical composition and compliance, followed by locally rolled from imported billets (μ = 101.2), TMT steel rods (μ = 101.0), and ordinary steel rods (μ = 100.6). Concerning CEV1 and CEV2, it was observed that all the brands were fully compliant within the maximum permissible ranges given in the local, foreign and international standards except an ordinary steel bar of Brand 16, which has value beyond the specified limits of CEV1. This study also shows that all imported and 77.8% of locally-rolled steel bars are low-carbon steel as specified by the selected standards.

Shear behaviour of RC-UHPFRC composite beams without transverse reinforcement

Strengthening existing reinforced concrete (RC) beams and slabs using a thin layer of ultra-high performance fibre reinforced cementitious composites (UHPFRC), plain (U) or reinforced (RU) with ordinary steel bars, has been shown to be a very effective way of increasing the flexural capacity in hogging moment regions. However, as the increase in the flexural strength can be very significant, the shear strength of the composite RC-RU or RC-U elements may govern the capacity of the strengthened element and must be conveniently assessed to provide suitable design recommendations. In this regard, the available experimental evidence concerning the shear strength of beams (or one-way shear strength for slabs) is relatively limited. In this work, the results of an experimental campaign are presented where the influence of important parameters was systematically evaluated, namely the reinforcement ratios in the original RC beam and the new UHPFRC layer, the size effect, the thickness of the UHPFRC layer and the sign of the being moment - hogging or sagging - changing the state of stress in the UHPFRC layer from tensile to compressive.The structural behaviour is discussed, and an analytical approach for calculating the shear strength is evaluated.

The Seismic Performance of New Self-Centering Beam-Column Joints of Conventional Island Main Buildings in Nuclear Power Plants

In order to improve the deformation energy consumption and self-centering ability of reinforced concrete (RC) frame beam-column joints for main buildings of conventional islands in nuclear power plants, a new type of self-centering joint equipped with super-elastic shape memory alloy (SMA) bars and a steel plate as kernel components in the core area of the joint is proposed in this study. Four 1/5-scale frame joints were designed and manufactured, including two contrast joints (a normal reinforced concrete joint and a concrete joint that replaces steel bars with SMA bars) and two new model joints with different SMA reinforcement ratios. Subsequently, the residual deformation, energy dissipation capacity, stiffness degradation and self-centering performance of the novel frame joints were studied through a low-frequency cyclic loading test. Finally, based on the OpenSees finite element software platform, an effective numerical model of the new joint was established and verified. On this basis, varying two main parameters, the SMA reinforcement ratio and the axial compression ratio, a simulation was systematically conducted to demonstrate the effectiveness of the proposed joint in seismic performance. The results show that replacing ordinary steel bars in the beam with SMA bars not only greatly reduces the bearing capacity and stiffness of the joint, but also makes the failure mode of the joint brittle. The construction of a new type of joint with consideration of the SMA reinforcement and the steel plate can improve the bearing capacity, delay the stiffness degradation and improve the ductility and self-centering capability of the joints. Within a certain range, increasing the ratio of the SMA bars can further improve the ultimate bearing capacity and energy dissipation capacity of the new joint. Increasing or decreasing the axial compression ratio of column ends has little effect on the overall seismic performance of new joints.

Shaking table test of concrete columns hybrid reinforced by steel/FRP bars

Post-earthquake residual deformation can be decreased due to the designable post-yield stiffness of concrete column reinforced by steel bars/fiber reinforced polymer (FRP) bars. Shaking table tests of three concrete columns with similar initial stiffnesses were conducted, where the longitudinal reinforcement included ordinary steel bars, steel-FRP composite bars (SFCBs) and hybrid reinforcement (steel bars and FRP bars, C–H). The measurements included acceleration response and strain development. The test results showed that the absolute and relative peak ground acceleration (PGA) responses of different columns were similar to one another. The residual strain in the anchorage region was not consistent (tension or compression) and was affected by the longitudinal reinforcement type and the amplitude of the input PGA. For ordinary reinforced concrete (RC) columns, the plastic strain of steel bars developed rapidly after the input ground motion PGA reached 100 Gal, and the corresponding residual strain also developed dramatically. For the SFCB column, even after the peak strain reached 15,000 με, the residual strain was still below 500 με. For hybrid column C–H, the residual strain of the FRP bar was similar to that of the SFCB column. Even when the input wave PGA reached 560 Gal with concrete cover spalling and steel bar buckling, no damage was observed on the FRP bars. In general, compared to ordinary RC columns, concrete columns with hybrid steel and FRP bar reinforcement can achieve a smaller residual deformation, while SFCB reinforced columns can be constructed in severe environments due to a good anti-corrosion performance, such as in offshore structures.