Performance Of Columns Research Articles

Microchip gas chromatographic columns dedicated for space exploration: Stationary phase coating, setup optimization and evaluation of column performances

This work is the first part of a project aiming to specifically design gas chromatographic microcolumns for space exploration. In particular, this study explored the functionalization and characterization of silicon/glass microchip gas chromatographic columns designed with a serpentine-shaped channel having an internal square cross-section. This microcolumn can be connected using a robust fluidic manifold with removable capillary connections to a conventional gas chromatograph or implemented in a prototype instrument for space exploration. First, benchtop gas chromatographic system was optimized in terms of injector liner volume, internal diameter (I.D.) of the capillary connections and data frequency of detection to ensure an optimal evaluation of column efficiency. Junction capillaries of 100 μm I.D., a liner of 1.2 mm I.D. and a detection acquisition frequency of 100 Hz were found to be the optimal set-up and parameters. Moreover, the stationary phase coating velocity was slowed-down to increase column efficiency by 100 %. Then, the performances of a square cross-section capillary column were compared with those of a conventional circular cross-section column. The coating efficiencies were estimated at 55 % and 42 % for circular and square internal cross-section geometries respectively, demonstrating that the square section geometry did not affect significantly the column performances. Stationary phase films of different thicknesses, from 0.032 to 0.260 µm, were coated on different microchips of the same production batch to assess the influence of film thickness on the chromatographic performances. Microchips performance was evaluated through Golay's plots, and some of the microchips were also studied by optical microscopy. The efficiency and retention capacity of our microchip column is shown to be highly dependent on the film thickness (9,000 plates.m-1 with k = 0.12 for the thinnest film and up to almost 4,000 plates.m-1 with k = 0.93 for the thickest film). Finally, the coating process repeatability was validated by producing three identical microchips with RSD of 4.8 % for the average number of theoretical plates.

Experimental and theoretical study on axial compression behaviour of the modular combined column

Between the modular units of the modular steel building, there exists a combination of the adjacent modular columns. Due to the gaps between the modular columns and the lack of horizontal connections, the integrity of the modular steel structure is weak, which limits the use of modular steel structures in high-rise buildings. This paper proposes a kind of modular combined column realized the connection of modular single columns through the connectors and concrete, which can improve the integrity of the modular steel building. The assembly process of this new modular combined column is described. For axial compressive performance tests, four modular combined column specimens were designed, each with different height or different number of connecting plates. The axial compressive bearing capacity, ductility, stiffness, and other mechanical parameters of the specimens were analyzed according to the phenomena and load-displacement curves of the test. Then, the axial compression failure mode of the modular combined column specimens is compared and analyzed in conjunction with the finite element model. The results indicate that the axial compressive performance and ductility of the combined column suggested in this research are exceptional. The connector can enhance the overall mechanical qualities of the combined column by augmenting the restraining impact of concrete. Finally, the theoretical equation of the axial compression bearing capacity of the modular combined column is obtained by employing the superposition principle, and the equation's reliability is confirmed, along with the test results and the results of the numerical analysis.

Experimental and simulation study on seismic performance of seawater sea-sand PVA cementitious composite columns with GFRP bars

The seismic properties of seven seawater sea-sand (SWSS) PVA cementitious composite columns with Glass Fiber Reinforced Polymer (GFRP) bars were studied. The effects of four parameters, namely polyvinyl alcohol (PVA) fiber content, axial compression ratio, cementitious composite strength and stirrup spacing, on the seismic performance of composite columns were analyzed. The failure of the specimen was observed, and the hysteresis curve, skeleton curve, stiffness degradation, energy dissipation capacity, ductility and strain of the specimen were analyzed. The test results show that the large chip-based spalling will occur when the specimen without fiber incorporation is damaged, and the incorporation of PVA fiber, the reduction of stirrup spacing and the reduction of axial compression ratio will delay the rate of crack formation and development. In addition, through cross-section analysis and considering the reinforcement effect of PVA fibers, a proposed formula for calculating the horizontal bearing capacity of composite columns is proposed. Finally, the finite element model of SWSS PVA cementitious composite columns with GFRP bars is established, and it is found that increasing the strength grade of cementitious materials can greatly improve the seismic performance of composite columns. The conclusions could be references for the engineering application. In the context of the global emphasis on green development and environmental protection, seawater and sea-sand cementitious composites and components with fiber reinforcement will have a wide range of application prospects in the construction of coastal areas.

Axial compression behaviour of square steel tubes encased by and filled with high-strength recycled aggregate concrete

The axial compression behaviour of square steel tube (SST) columns encased with recycled aggregate concrete (RAC) and filled with RAC (RAC-encased RACFSST) columns was investigated. Using high-strength concrete, five specimens were tested under axial compression until failure. The experimental parameters included the coarse aggregate type, stirrup spacing, wall thickness of the SST and the existence of cross-tie bars in the SST. The failure mode, load–displacement curves, load–strain curves and ductility of the composite columns were obtained. The impacts of the various parameters on the mechanical performance of the RAC-encased RACFSST columns were evaluated. The failure modes of the composite columns were comparable. The inclusion of RAC enhanced the load-bearing capacity (LBC) of the column, but negatively affects its ductility and deformation capacity. Increasing the wall thickness of the SST and reducing the stirrup spacing significantly improved the axial compressive performance of the columns, as mainly reflected in the axial compressive capacity and ductility, respectively. Cross-tie bars inside the SST improved the LBC and deformation capacity. The axial bearing capacities of the columns and those in other studies were determined using existing codes. The computed results were very consistent with the experimental data.

Eccentric compression behavior of CFRP-confined reactive powder concrete-filled steel tube slender columns

Ultra high and large-span structural components are needed in urban modernization construction to meet the engineering requirements. Reactive powder concrete-filled steel tubes (RPCFSTs) provide a cost-effective and efficient solution for optimizing space utilization in super high-rise buildings and enhancing the crossing capacity of bridge, which accords with such development. However, these components have inherent drawbacks in terms of local buckling and corrosion resistance. The use of carbon fiber reinforced polymer (CFRP) confinement to suppress this innate deficiency has been proven to show great advantages in limited trial results. This article establishes a comprehensive test scheme to investigate the eccentric compression performance of CFRP-confined RPCFST columns. A total of 11 specimens were prepared and subjected to biased compression test by varying the component length (400, 800, 1200, and 1600 mm), number of CFRP layers (0–3), and load eccentricity (0, 10, 20, 30, and 40 mm). The results showed that the CFRP confinement could effectively enhance the bearing capacity and energy dissipation capability of RPCFST columns while delaying the local buckling of slender specimens with low slenderness ratios. The improvement of ultimate load due to CFRP confinement exceeded 42.5 %. However, in specimens with higher slenderness ratios and with increasing load eccentricity, the confinement effect of the steel tube on the core RPC tended to weaken. An N–M interaction model for slender CFRP-confined RPCFST columns was established, and this model was validated to be in good agreement with the experimental results. The conclusions drawn from this study might given a solid foundation for the future application of CFRP-confined RPCFST structures.

Lateral performance of circular wooden columns reinforced with high-performance bamboo-based composite

This study researches the lateral performance of wooden columns strengthened with the non-damage reinforcement method, which used high-performance bamboo-based composite (HPBBC) materials and steel strips to form a hollow reinforcement system and then jacketed and reinforced the wooden columns. Six wooden columns strengthened by non-damage reinforcing methods were subjected to low cyclic loading tests under horizontal loads with a constant axial pressure ratio. The horizontal loads, displacements, and strain distributions of different locations at the column root were measured. The experimental results showed that the reinforcement method improved the lateral performance of wooden columns by about 4.96–58.54 %. Owing to the protective effect of the reinforcement system, the development of tensile damage to the wooden columns was delayed, but the breaking location was still the column root. In addition, the energy dissipation capacity and equivalent viscous damping coefficient of the reinforced wooden columns were significantly improved. The deformation of the strengthened column root conforms to the plane section assumption, while the deformation of the reinforcement system was lagged due to the absence of colloid and shear connectors between the wooden column and the reinforcement system. A bending capacity equation for the reinforced wood column was deduced based on the strain distribution in the damaged section. The error between the calculated and experimental results was within 13 %.

Axial compressive behavior of hybrid CFRP-concrete-steel double-skin tubular columns

This paper investigates the axial compressive behavior of hybrid carbon fiber reinforced polymer (CFRP)-concrete-steel double-skin tubular columns (DSTCs) under core cross-section loading. A total of 18 DSTCs are tested, comprising 9 stub columns and 9 long columns. The thickness and fiber winding direction of the CFRP tube, hollow ratio, and slenderness ratio are compared. The impact of these factors is examined on failure modes, ultimate strength, and ductility of DSTCs. The tested results indicate that the failure modes of DSTCs are correlated with the fiber winding direction of the CFRP tube. Concrete confined by CFRP tubes with a fiber winding direction at 90° demonstrates minimal damage. The ultimate load of DSTCs is enhanced by increasing the thickness of CFRP tubes, whereas it is negatively influenced by both the hollow ratio and slenderness ratio. The ductility of DSTCs improves as the thickness of CFRP tubes and the hollow ratio increase. Additionally, the established FEA is utilized for stress analysis as well as parametric study of DSTC columns. The results show that the thickness of CFRP tubes, the modulus of elasticity in the circumferential direction of CFRP tubes, the slenderness ratio, and the hollow ratio have a greater effect on the axial compressive performance of DSTC long columns. The strength of concrete, the strength and thickness of steel tubes have less influence on the axial compressive performance of DSTC long columns. Typical FRP-confined concrete models are utilized to validate the axial ultimate strength. A new stability coefficient is recommended to improve the precision.

Seismic loading assessment of a novel structural column testing equipment

In experimental investigation on seismic performance of structural columns, it is particularly important that the loading device can reproduce a structure’s gravity load and apply a lateral seismic load at the same time, and both should be decoupled. Based on this concept, a two-dimensional multi-usage structural testing equipment (ZJU-MUST) has been developed with the following features: (1) the horizontal loading is ensured perpendicular to the vertical loading, and the loads in different directions are decoupled; (2) horizontal and vertical forces applied to testing specimen can be directly measured without the need to correct the secondary effects due to friction or vertical loading; (3) it is more reliable and suitable for cyclic loading under variable vertical forces. A 2600 mm high steel tubular column was designed for both cyclic loading tests and pseudo-dynamic tests. From the column test, the control system of ZJU-MUST as well as its performance in real-time data transmission and calculation can be verified.

Axial and eccentric compressive behavior of partially encased channel–concrete composite columns with bolted connections in modular buildings

This paper introduces a novel partially encased channel–concrete composite (PECC) column for modular buildings, aiming to eliminate the need for cast-in-place concrete and facilitate rapid assembly. The PECC column consists of two prefabricated modules connected by high-strength bolts. To evaluate the column's viability, six slender specimens—one bare steel column and five composite columns—were tested under axial and eccentric compression. Variables considered included the presence of concrete, the type of transverse connections, bolt spacing, and load eccentricity ratio. The compression performance of the PECC columns was analyzed by examining their failure patterns, load–deformation responses, initial stiffness, compressive capacity, and ductility. Test results revealed that the PECC columns failed due to global buckling, concrete spalling, and crushing. The bolted connections effectively prevented module separation, enabling the PECC columns to exhibit favorable compressive behavior. The reinforced concrete encased in the channel delayed the column's buckling failure, increasing its initial stiffness and compressive capacity by 98% and 198%, respectively. Using perforated steel plates instead of transverse links between the concrete and the channel enhanced the column's initial stiffness by 20% but had little effect on its compressive capacity. Reducing the bolt spacing improved the column's initial stiffness and compression resistance by 50% and 5%, respectively. Additionally, a finite element model for the PECC columns was developed and validated against test results. Finally, simplified formulas derived from Eurocode 4 were proposed to estimate the resistance of PECC columns under axial and eccentric compression.

Bridged Ethylene Polyethylene Oxide Surfaces to Improve Packing Materials for Widepore Size Exclusion Chromatography.

Here, we describe the preparation of bridged ethylene polyethylene oxide (BE-PEO) surface-modified silica packing materials for size exclusion chromatography. BE-PEO surface-modified silica was hydrolyzed and subsequent 1H nuclear magnetic resonance analysis of hydrolysis products confirmed the successful formation of BE-PEO bonded surface. Silica particles exhibiting 3µm diameters and 1000 Å nominal pore diameters were selected as a base material for this work out of the critical need to improve analytical capabilities for the testing of cell and gene therapy drug products. Accelerated high pH aging study revealed significant enhancement in column stability. Multi-angle light scattering noise measurements showed inordinately lower baseline noise. Moreover, we evaluated the chromatographic performance of BE-PEO silica-packed columns through separations of a protein test mixture, DNA ladder, monoclonal antibody-based therapeutics, and adeno-associated viruses. BE-PEO silica columns demonstrated high resolution, high recovery separations that were confirmed to be reproducible and capable of extended column lifetimes and exhibited low ionic and hydrophobic secondary interactions. In summary, BE-PEO silica particles have yielded a new level of performance, improved base stability, and inherently lower baseline noise. These novel widepore particles will facilitate more sensitive size-based detection and characterization of large biologics in the form of advanced gene therapy products.

GFRP-Reinforced Concrete Columns: State-of-the-Art, Behavior, and Research Needs

This comprehensive review paper delves into the utilization of Glass Fiber-Reinforced Polymer (GFRP) composites within the realm of concrete column reinforcement, spotlighting the surge in structural engineering applications that leverage GFRP instead of traditional steel to circumvent the latter’s corrosion issues. Despite a significant corpus of research on GFRP-reinforced structural members, questions about their compression behavior persist, making it a focal area of this review. This study evaluates the properties of GFRP bars and their impact on the structural behavior of concrete columns, addressing variables such as concrete type and strength, cross-sectional geometry, slenderness ratio, and reinforcement specifics under varied loading protocols. With a dataset spanning over 250 publications from 1988 to 2024, our findings reveal a marked increase in research interest, particularly in regions like China, Canada, and the United States, highlighting GFRP’s potential as a cost-effective and durable alternative to steel. However, gaps in current knowledge, especially concerning Ultra-High-Performance Concrete (UHPC) reinforced with GFRP, underscore the necessity for targeted research. Additionally, the contribution of GFRP rebars to compressive column capacity ranges from 5% to 40%, but current design codes and standards underestimate this, necessitating new models and design provisions that accurately reflect GFRP’s compressive behavior. Moreover, this review identifies other critical areas for future exploration, including the influence of cross-sectional geometry on structural behavior, the application of GFRP in seismic resistance, and the evaluation of the size effect on column strength. Furthermore, the paper calls for advanced studies on the long-term durability of GFRP-reinforced structures under various environmental conditions, environmental and economic impacts of GFRP usage, and the potential of Artificial Intelligence (AI) and Machine Learning (ML) in predicting the performance of GFRP-reinforced columns. Addressing these research gaps is crucial for developing more resilient and sustainable concrete structures, particularly in seismic zones and harsh environmental conditions, and fostering advancements in structural engineering through the adoption of innovative, efficient construction practices.

Enhancing concrete column performance: a comparative study of full vs. partial CFRP confinement techniques

Enhancing concrete column performance: a comparative study of full vs. partial CFRP confinement techniques

Evaluation of activated carbon fiber packed-bed for the treatment of gas-to-liquid wastewater: experimental, modeling and ASPEN Adsorption simulation

AbstractThis study investigates the continuous adsorption treatment of gas-to-liquid (GTL) wastewater from the Fischer-Tropsch process using activated carbon fiber (ACF) as the adsorbent. ACF, characterized by a high surface area of 1232 m²/g, was utilized to treat actual GTL wastewater, which contains long and short-chain alcohols, fatty acids, and other hydrocarbons. Experimental analysis, packed-bed modeling and simulation using ASPEN Adsorption were employed to understand the dynamics of the adsorption process. The experimental setup involved a bench-scale column packed with specified masses of ACF, with GTL wastewater pumped upward through the column at varying flow rates. Breakthrough curves were constructed to assess column performance, with parameters, such as feed flow rate (5 and 10 mL/min) and packing mass (5 and 10 g) systematically varied. The results demonstrate a significant influence of these parameters on column performance, with higher flow rates initially accelerating adsorption kinetics. Conversely, increasing packing mass extends the duration of column saturation, improving efficiency. Empirical models, including the Yoon-Nelson and El-Naas et al. models were applied to fit the experimental data, with the latter showing superior performance in representing the adsorption mechanism within the column. Quantitative analysis of model fitting using Akaike Information Criteria (AIC) identified the Yoon-Nelson and El-Naas et al. model as the most suitable for describing the GTL wastewater/ACF system, with an AIC weight parameter of 0.33 and R2 averaging 86.5%. Furthermore, simulation results from ASPEN Adsorption exhibited strong agreement with experimental data, validating its efficacy for simulating liquid adsorption processes. The study provides valuable insights into the design and optimization of large-scale wastewater treatment systems, offering practical solutions to address global water challenges.

A New Continuous Strength Method for Prediction of Strain-Hardening Performance of High-Strength Aluminum Alloy Cylindrical Columns

This paper aims to develop a new continuous strength method (CSM) to more accurately predict the strain-hardening characteristics of high-strength aluminum alloy circular hollow sections (CHSs) under axial compression. A total of 11 stub column specimens made of 7A04-T6 and 6061-T6 aluminum alloys underwent testing. Additionally, 16 sets of experiment data were gathered from open sources, encompassing various aluminum alloy types such as 6082-T6, 6061-T6, and 6063-T5. Validated by experimental result, the finite element (FE) model was applied in a series of comprehensive parameter studies, supplementing the limited test result of high-strength aluminum alloy stub columns. Based on the experiment and FE results, this paper proposes a new CSM relation to determine the cross-sectional resistance of high-strength non-slender CHS aluminum alloys under compression. The cross-sectional resistance obtained from tests are compared with predicted strengths determined using the European code, as well as the solution of the CSM proposed in a previous study and in this paper. The comparison illustrates that the strength predictions in the European code and the previous study are conservative. Compared with the European code and the previous study, the strength prediction formula proposed in this paper improves accuracy by 11% and 5%, respectively, while reducing scatter by 8.4% and 2%, respectively.

Experimental and Transformer-Based Study on Seismic Behavior and Plastic Hinge Length of RC Columns Reinforced with End-Fixed Ultra-High Strength Rebars

The application of machine learning (ML) in structural engineering is receiving increasing attention recently. This paper experimentally studies three self-restoring reinforced concrete (SRRC) columns reinforced with low-bond ultra-high strength rebars, to first discuss the reliability and evaluation of the SRRC columns under multiple reversed cyclic (MRC) loads induced by strong earthquakes, and to also first introduce the Transformer method into the analysis and discussion of structural tests. The tests confirmed the superior seismic behavior and high self-centering performance of the columns and presented how MRC loads affect the seismic performance of SRRC columns in terms of the lateral load-carrying capacity and energy dissipation capacity. Superior to conventional methods, a high-accuracy Transformer-based model is proposed to evaluate the plastic hinge height (PHL) of the tested SRRC columns compared with the other three algorithms (MLP, KNN, and XGBoost). Furthermore, the Shapley Additive exPlanations (SHAP) approach is adopted to explain the insight relationship between the structural parameters and PHL of the columns.

Rubberized reinforced concrete columns under axial and cyclic loading

The experimental study presented in this research was conducted to understand the performance of rubberized concrete columns under axial loads and numerically analyze the conduct of rubberized reinforced concrete (RRC) columns under cyclic loads. Twelve large-scale columns with square and circular cross sections were utilized to carry out experimental testing. Under axial loading, fine aggregate was replaced in percentages of 0%, 10%, and 15% with crumb rubber (CR). Square RRC columns were examined by a finite element program (ABAQUS) under cyclic loading. The experimental results indicated that the columns with crumb rubber had a lower load capacity than those without crumb rubber when exposed to axial loads. The numerical results were in good alignment with the experimental results, indicating that the simulated model may simulate the behavior of rubberized concrete columns under both axial and cyclic loads. According to the numerical analyses, the lateral displacement was significantly improved for rubberized reinforced concrete columns with 10% and 15% replacement of fine aggregates compared to columns without CR. Adding 10% and 15% of crump rubber to the fine aggregate in reinforced concrete columns increased the displacement ductility. The equivalent viscous damping ratio was enhanced by 33.67% when increasing crumb rubber (CR) from 0% to 10%, and when crumb rubber (CR) replacement became 15%, the damping ratio increased to 44.02%.The rubberized reinforced concrete columns showed a more ductile reaction than the traditional reinforced concrete columns, as evidenced by their softer post-peak response.

Eccentric compression performance of coral concrete-filled aluminum alloy tube (CCFAT) circular short columns

Coral concrete, utilizing coral reef bodies in place of traditional aggregates, shows promising prospects use in island projects. The use of aluminum alloy-reinforced coral concrete columns effectively enhances the load-bearing capacity of these structures. This study aims to investigate the performance of aluminum alloy circular tube-reinforced coral concrete short columns under eccentric compression. The study involved designing fifteen short columns for eccentric compression experiments, focusing on key parameters such as aluminum content (α), eccentricity (e0), and coral concrete strength (fc). The study obtained failure modes, bearing capacities, and load-deformation relationships, and analyzed the impacts of aluminum content, eccentricity, coral concrete strength, and hoop coefficient (ξa) on the columns’ strength, stiffness, and ductility. Subsequently, a finite element parameter expansion analysis using Abaqus was performed. Ultimately, a correction coefficient model was developed, compared with existing international specifications, and used to establish a suitable calculation model for the bearing capacity of CCFAT eccentric short columns. The results indicated that CCFAT eccentric short columns predominantly experienced bending failure. The stresses in the aluminum alloy round tube can reach the conditional yield strength, effectively collaborating with the concrete. The load-deformation relationship did not exhibit an intensification stage, and the lateral deflection curves tended to follow sinusoidal half-wave patterns. During the initial loading stage, adherence to the plane-section assumption was observed, with the hoop effect primarily manifesting in the compression zone. The strength index showed an approximately quadratic relationship with ξa, the stiffness index showed a positive correlation with ξa, and the ductility index demonstrated a strong positive association with ξa. The correction coefficient model, along with AIJ (2001), can be employed for calculating the bearing capacity of CCFAT eccentric short columns. This study introduces the novel concept of aluminum alloy tube-reinforced coral concrete columns as a composite structure for island civil engineering construction. Beyond the benefits of traditional steel tube concrete, these composite columns are expected to reduce engineering costs, shorten construction timelines, and address durability concerns through the incorporation of marine coral stones and fragments as concrete aggregates.

The methodology for evaluating the fire resistance performance of concrete-filled steel tube columns by integrating conditional tabular generative adversarial networks and random oversampling

Artificial Intelligence (AI) technology has emerged as a powerful tool for addressing various complex issues within engineering structures. Accurately assessing the fire resistance performance of Concrete-Filled Steel Tube (CFST) columns poses a significant challenge for researchers. The scarcity of CFST column fire resistance test data presents a hurdle in the development of Machine Learning (ML) models. To tackle this issue, this study proposes a novel ML approach that integrates Conditional Tabular Generative Adversarial Networks (CTGAN) and Random Oversampling (ROS) for evaluating CFST column fire resistance performance. CTGAN technology is used to generate synthetic datasets to alleviate data scarcity issues, while ROS technique is used to balance the dataset. To validate the effectiveness of this method, detailed experimental tests using eight ML algorithms were conducted on both real and synthetic datasets, with results indicating superior performance on the synthetic dataset compared to the real dataset. The optimal model in the synthetic dataset achieves an Accuracy, Precision, Recall, and F1-Score of 0.972, 0.973, 0.972, and 0.972, respectively. Furthermore, extensive comparative analyses and practical applications of the proposed method were conducted, revealing its exceptional performance in evaluating the fire resistance of CFST columns. To facilitate ease of use and operation in practical engineering, a visual interface was developed. The introduction of this technique offers a novel solution for researchers and engineers in the field of structural fire engineering.

Damage-free self-centering steel columns incorporating SMA bolts and replaceable steel angles

Steel moment-resisting frames (MRFs) are one lateral force-resistant structural system commonly used in high seismicity areas. The current seismic design practice for MRFs expects to develop plastic hinges at the beam ends to dissipate earthquake input energy. Meanwhile, plastic hinges also form almost unavoidably at the column bases of the first story due to the strong-base-weak-column design philosophy. However, concentrated deformation in the predetermined plastic hinges may lead to considerable damage in structural components. The accompanying large residual drifts can substantially compromise post-earthquake reparability and normal functionality. Hence, this paper presents a novel type of self-centering (SC) steel column base incorporating shape memory alloy (SMA) bolts and replaceable steel angles as a damage-free solution. First, the working principle of the column bases is described. Subsequently, the seismic performance of the steel columns is experimentally evaluated by considering the influences of the steel angles and repeated loading scenarios, and the replaceability of steel angles. Results show the novel steel column bases exhibit satisfactory flag-shaped hysteresis loops with excellent SC capability and stable energy dissipation, whereas almost all the damage is concentrated in the steel angles that can be replaced rapidly after the cyclic loading if required. The deformed columns are restored to their upright positions instantaneously with negligible residual deformation after unloading. More importantly, the steel column stays damage-free, and the SMA bolts with prestrain remain tightened. This enables the steel columns to maintain high functionality to withstand immediate aftershocks or future earthquakes, explicitly achieving seismic resilient design.

Experimental investigation on the compression-bending performance of rubberized concrete columns confined by galvanized corrugated steel tubes

In the construction of building structures, numerous components simultaneously experience axial pressure and lateral bending moments. This concurrent influence plays a pivotal role in structural design considerations. This paper presents an experimental investigation of the compression-bending performance of rubberized concrete-filled corrugated steel tubes (RuCFCST). Twenty-two specimens were tested to evaluate the effect of eccentricity, length-diameter ratio, and confinement factor on the failure mode, load-displacement response, stiffness, compression-bending capacity, and ductility of the columns. The study also conducted a stress analysis on the corrugated steel tube to understand its confinement effect on the core rubberized concrete. The results demonstrate that the confinement factor emerges as a pivotal and sensitive parameter that impacts the compression-bending bearing capacity of RuCFCST columns. The study further elucidated the non-uniform confinement and failure mechanisms of the RuCFCST column, and subsequently assessed the applicability of the specimen's compression-bending bearing capacity as calculated by current specifications. The proposed RuCFCST columns offer new insights and serve as a reference for developing composite member systems with large hoop stiffness, small wall thickness, and environmental sustainability.