Strength Prediction Equations Research Articles

Impact of steel tube wall thickness on axial compression behavior of reinforced and recycled aggregate concrete-filled square steel tube short columns

Tests and numerical simulations were conducted to investigate the impact of wall thickness of steel tube on the axial load performance of reinforced and recycled aggregate concrete (RAC)-filled square steel tube short columns (R-RACFST). The test groups consisted of R-RACFST, concrete-filled square steel tube (CFST), and RAC-filled square steel tube (RACFST). Each group had five different wall thicknesses of the steel tube, and the RAC infill was made of 100 % recycled coarse aggregate (RCA). Two replicate specimens were prepared for each group and wall thickness. The tests were used to analyze the effect of steel ratio on failure mode, loading performance, and ductility. The analyses clarified that the reinforcement effectively enhanced the confinement effect on RAC, compensating for the inadequate confinement of the square tubes and the brittleness of the RAC with 100 % RCA. To further understand the acting role of reinforcement, numerical parametric studies were conducted. A novel numerical model for R-RACFSTs was established and verified with the tests. A total of 81 models were then simulated, considering the coupling effects between the wall thickness of the steel tube, the amount of reinforcement, and the strength of RAC. Based on the simulations, the coupling relationship between the steel tube and reinforcement, as well as the optimal range of steel ratio, were determined. Additionally, strength prediction equations were studied and proposed. The findings indicate that it is feasible to fill RAC with 100 % RCA in R-RACFSTs; when combined with appropriate reinforcement, R-RACFSTs with thinner tubes can achieve the same or better performance compared to RACFSTs with thicker tubes; the recommended reasonable range for the steel ratio and corresponding confinement coefficient in R-RACFSTs are 6.4 % to 13.7 % and 1.00 to 2.04, respectively; the predictions proposed are accurate and reliable.

Bond strength prediction of externally bonded reinforcement on groove method (EBROG) using MARS-POA

The Externally Bonded Reinforcement on Grooves (EBROG) method represents an advancement in externally bonded reinforcement (EBR) techniques, specifically addressing the challenge of premature debonding often encountered in conventional Fiber Reinforced Polymer (FRP) applications directly bonded to concrete. This article introduces a novel and straightforward mathematical equation for predicting bond strength in the EBROG method using soft computing techniques for the first time. The study delves into the combined potential of the Multivariate Adaptive Regression Spline (MARS) model and the Pelican Optimization Algorithm (POA) for bond strength prediction in this method. The input parameters include FRP width, FRP thickness, elasticity modulus of FRP, concrete strength, groove length, groove width, and groove depth, while the output is EBROG bond strength. The study demonstrates exceptional accuracy with R2 values of 0.9629 for training and 0.9623 for testing, highlighting the model’s precision. The proposed bond strength prediction equation for the EBROG method undergoes validation against existing models, encompassing thirteen equations for EBR and a recent one specific to EBROG. Statistical metrics confirm the accuracy and reliability of the proposed equation. Notably, FRP stiffness emerges as the parameter with the highest relative importance, while groove width exhibits the lowest impact on bond strength.

Joint shear strength prediction for fiber reinforced concrete beam-to-column connections

Beam-to-column joints experience substantial shear forces and deformations, playing a pivotal role in maintaining the overall stability and integrity of moment-resisting frames under earthquake loading. If fiber reinforced concrete is used instead of reinforced concrete, beam flexural failure can be achieved, which leads to a ductile behavior and increased energy dissipation capacity, when compared to joint shear failure. To ensure a ductile failure mode, accurate prediction of the joint shear strength is essential. However, there are only a limited number of analytical studies on predicting the shear strength of fiber reinforced concrete joints, most of which are only applicable to steel fibers. In this study, a comprehensive database of prior experiments conducted on fiber reinforced concrete beam-to-column connection subassemblies is compiled. Based on Pearson Correlation Analyses, the factors influencing the seismic response are determined to be the composite tensile cracking strength, axial load on the column, aspect ratios of member dimensions, and specific fiber properties such as aspect ratio and volume fraction. A joint shear strength prediction equation is then developed utilizing statistical nonlinear regression method. Validation against experimental data confirms that the proposed equation provides conservative estimates of joint shear strength and can be utilized for composites with any fiber type, even hybrid fibers; in contrast to existing equations which often lead to overestimation of strength and restricted to a specific fiber type. Moreover, the proposed equation provides engineers a practical tool to assess the seismic behavior of such connections, which has not been addressed by current structural design codes yet. The improved accuracy of the proposed equation, demonstrated by the lowest mean absolute error and coefficient of variation and the highest coefficient of correlation, positions it as a promising candidate for integration into structural design codes.

Predicting the strength, density, and porosity of rocks from roll crusher tests

The density, porosity, and strength of rocks are fundamental in the design of geo-engineering projects. Determining these properties requires the preparation of smooth core samples, which is usually impossible for soft rocks. Besides, only fragmented samples may be available in some projects. A method for predicting rock properties from rock particles such as drilling debris would therefore be useful. This study was undertaken to develop prediction equations for compressive strength (UCS), tensile strength (BTS), density, and porosity values from the crushability index (CI) obtained from rock fragments. The results showed that UCS, BTS, density, and porosity were strongly correlated with the CI. The physical characteristics and strength of rocks may be predicted with the help of the derived equations. The CI test is a valuable tool for estimating rock properties in drilling projects and in situations where core specimens are not available.

Evaluation of the Properties of High Strength Lightweight Concrete with High Temperature History

In this study, we evaluated the compressive strength and ultrasonic velocity based on the temperature and age of ordinary aggregate and lightweight aggregate concrete (30 and 60 MPa) and examined their correlation. The unit weight and compressive strength of ordinary aggregate and lightweight aggregate concrete were measured to evaluate the mechanical properties and examine the correlation between ultrasonic velocity and compressive strength. The W/B ratio was set at 0.41 and 0.28, and measurements were made at 1, 3, 7, 28, 56, and 91 days. The physical properties were evaluated at 23, 100, 200, 300, 500, and 700 ℃. In all test specimens, compressive strength and ultrasonic speed increased with age; and the higher the temperature, the lower the compressive strength and ultrasonic speed. By analyzing the correlation between ultrasonic velocity and compressive strength, a strength prediction equation in the form of an exponential function was found. Moreover, from the error rate test, we confirmed that the strength prediction equation generally had an error rate of 15% or less.

Laboratory mechanical properties and frost resistance of vibration-compacted cement–fly ash slurry and cement–fly ash-treated macadam mixtures

The objectives of this study were to characterize the compaction and mechanical characteristics and frost resistance of vibration-compacted cement–fly ash slurry (CFAS) and cement–fly ash-treated macadam (CFATM) mixtures and recommend the optimal ratio and dosage of cement–fly ash (CFA) based on laboratory compaction experiments, unconfined compressive testing, indirect tensile testing, and frost resistance testing. The effects of the CFA ratio and dosage, curing age, and gradation type on the mechanical strength and frost resistance were analyzed, and strength prediction equations were presented. Then, the optimal CFA ratio and dosage are recommended. The results show that the mechanical strength of CFAS and CFATM mixtures increased nonlinearly with increasing curing age. Gradation type, CFA ratio, and CFA dosage affected the conventional, initial, and ultimate mechanical strengths of these mixtures. A CFATM mixture cured for a longer duration with self-developed skeleton-dense gradation and the addition of less fly ash exhibited better frost resistance. To maximize the mechanical strength of CFAS and CFATM mixtures, the CFA ratio should not exceed 1:1 and 1:1–1:1.5, respectively. In addition, 3.5%–4.0% cement and 4.0%–7.0% fly ash should be used in the CFATM base or subbase to obtain optimal results. This paper provides a new option for the design of CFAS and CFATM mixes.

Reference values for respiratory muscle strength and maximal voluntary ventilation in the Brazilian adult population: A multicentric study.

To determine reference values and propose prediction equations for respiratory muscle strength, maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and endurance by means of maximal voluntary ventilation (MVV) in healthy Brazilian adults. Anthropometric data, level of physical activity, pulmonary function, and respiratory muscle strength and maximal voluntary ventilation of 243 participants (111 men and 132 women) aged 20 to 80 years were assessed at three cities in the southeast and northeast region of Brazil. Mean maximal respiratory pressures and MVV were higher in men (MIP = 111.0 ± 28.0; MEP = 149.6 ± 40.3; MVV = 150.6 ± 35.2) than in women (MIP = 87.9 ± 17.6; MEP = 106.7 ± 25.2; MVV = 103.4 ± 23.2; all p < 0.05). Based on regression models, the following prediction equations were proposed for men: MIP = 137-0.57 (age), R2 = 0.13, standard error of estimate (SEE) = 26.11; MEP = 179.9-0.67 x (age), R2 = 0.08, SEE = 38.54; and MVV = 206.3-1.18 x (age), R2 = 0.36, SEE = 28.08. Prediction equations were also proposed for women: MIP = 107.3-0.4 x (age), R2 = 0.16, SEE = 16.10; MEP = 127.4-0.43 x (age), R2 = 0.08, SEE = 24.09; and MVV = 146.3-0.86 x (age), R2 = 0.42, SEE = 17.56. Reference values for MIP, MEP, and MVV were determined in healthy Brazilian adults. Results from different Brazilian regions provided adequate prediction equations considering an ethnically heterogeneous population.

New prediction equations for knee isokinetic strength in young and middle-aged non-athletes

BackgroundThis study aimed to develop alternative prediction equations to predict isokinetic muscle strength at 60°/s based on anthropometric characteristics, including body mass, height, age, and sex for young and middle-aged non-athlete populations.MethodsThree hundred and thirty-two healthy non-athletic participants (174 females, 158 males) between 20 and 59 years underwent a 60°/s isokinetic knee joint concentric contraction test. Forty people were randomly selected for retesting to assess the reliability of the isokinetic instrument. Multivariate linear regression was used to establish extension peak torque (EPT) and flexion peak torque (FPT) prediction equations. Sixty extra participants were used individually to validate the prediction equations, and Bland Altman plots were constructed to assess the agreement of predicted values with actual measurements.ResultsThe result demonstrated that the instrument we used has excellent reliability. The multivariable linear regression model showed that body mass, age, and sex were significant predictors of PT (EPT: Adjusted R2 = 0.804, p < 0.001; FPT: Adjusted R2 = 0.705, p < 0.001). Furthermore, the equations we established had higher prediction accuracy than those of Gross et al. and Harbo et al.ConclusionThe equations developed in this study provided relatively low bias, thus providing a more suitable reference value for the knee isokinetic strength of young and middle-aged non-athletes.

Seismic performance of cold-formed steel centre-sheathed shear wall: Simulation and theoretical prediction

A cold-formed steel center-sheathed shear wall (CFS-CSSW) is proposed in this study to promote the formation and utilization of the diagonal tension bands of steel sheets to improve the lateral performance of CFS shear walls. The energy method was adjusted and adopted to characterize the lateral stiffness of CFS-CSSWs, and strength prediction equations were proposed based on the mechanics of the materials. Consequently, the calculation results indicate that the proposed theoretical models have a relatively high accuracy. Subsequently, the finite element (FE) modeling of the wall was performed and compared with experiments and theoretical analysis results after the accurate simulation of the screw connection, and parametric analyses were conducted based on the verified FE models to further validate the applicability of the theoretical models and discuss the factors influencing the seismic performance of the wall.

Explainable Data-Driven Ensemble Learning Models for the Mechanical Properties Prediction of Concrete Confined by Aramid Fiber-Reinforced Polymer Wraps Using Generative Adversarial Networks

The current study offers a data-driven methodology to predict the ultimate strain and compressive strength of concrete reinforced by aramid FRP wraps. An experimental database was collected from the literature, on which seven different machine learning (ML) models were trained. The diameter and length of the cylindrical specimens, the compressive strength of unconfined concrete, the thickness, elasticity modulus and ultimate tensile strength of the FRP wrap were used as the input features of the machine learning models, to predict the ultimate strength and strain of the specimens. The experimental dataset was further enhanced with synthetic data using the tabular generative adversarial network (TGAN) approach. The machine learning models’ performances were compared to the predictions of the existing strain capacity and compressive strength prediction equations for aramid FRP-confined concrete. The accuracy of the predictive models was measured using state-of-the-art statistical metrics such as the coefficient of determination, mean absolute error and root mean squared error. On average, the machine learning models were found to perform better than the available equations in the literature. In particular, the extra trees regressor, XGBoost and K-nearest neighbors algorithms performed significantly better than the remaining algorithms, with R2 scores greater than 0.98. Furthermore, the SHapley Additive exPlanations (SHAP) method and individual conditional expectation (ICE) plots were used to visualize the effects of various input parameters on the predicted ultimate strain and strength values. The unconfined compressive strength of concrete and the ultimate tensile strength of the FRP wrap were found to have the greatest impact on the machine learning model outputs.

Shear damage repair of masonry walls using different materials

In this research, the effects of different repairing materials and techniques used on damaged Masonry walls under an in-plane lateral loading were investigated. Seven clay brick walls with dimensions of (1200 × 935 × 115) mm were tested. The walls were tested until a visible crack was observed, later repaired, and tested again up to failure. The repairing materials consisted of grid configured strip materials (metal, plastic, flat webbing ‘textile’ and wild cane ‘organic’ strips), near surface mounted (NSM) steel re-bars and steel wires in mortar joints. Based on the experimental results, the repairing materials/techniques restored the shear strength by about 48–103% of the original strength. The ductility factor of the repaired walls ranged from 4.5 to 48.3 (flat webbing ‘textile’ highest). The energy dissipation ratio of the repaired walls ranged from 4.3 to 12.7 (flat webbing ‘textile’ highest). Prediction equations for shear strength are presented giving reasonable results compared to the experimental results.

Partially grouted masonry walls with different horizontal reinforcement types: North American-compliant experimental performance for low seismic risk areas

The type of horizontal reinforcement can play a major role in the shear response of partially grouted (PG) masonry walls, particularly in the damage pattern and the post-peak behavior. Bond beam reinforcement and bed joint reinforcement are the two reinforcement types most commonly used in practice; however, there is a lack of comparative studies between these two reinforcement strategies. To advance knowledge on this matter, this paper presents the results of an experimental study made up of 4 full-scale walls tested under cyclic lateral loading. Two height-to-length aspect ratios (H/L = 1.0, 1.86) and two reinforcement types per aspect ratio were considered. These walls were designed to reflect practical details and construction practices for PG walls in low seismic hazard areas.Lateral load tests showed that the peak strength of walls with similar aspect ratios had no significant difference regardless of the reinforcement type used. Bed-joint reinforcement proved to be a vital option as a shear reinforcement for controlling the crack width. The preliminary assessment of in-plane strength prediction equations for PG walls revealed that the general flexural analysis method provides a satisfactory estimation of flexural strength. In contrast, code-based equations had a highly conservative prediction of shear strength when imposing the upper limit. In addition, the Canadian Standards Association (CSA) and The Masonry Society (TMS) equations used to predict the in-plane shear strength had a noticeable discrepancy in the contribution of the equation's parameters, particularly in the axial stress, horizontal reinforcement, and the upper limit, which highlighted the need to revise and reconsider the contribution of each design parameter used by these expressions.

Loading performance of reinforced and recycled aggregate concrete-filled circular steel tube short column with different steel ratios

Experimental and numerical studies were conducted to clarify the influencing law of steel ratio on the mechanical properties of reinforced and recycled aggregate concrete (RAC)-filled circular steel tube short columns (R-RACFST) with 100% recycled coarse aggregate (RCA) replacement. Concrete-filled steel tube (CFST), RAC-filled steel tube (RACFST) and R-RACFST test series were designed using five different wall-thicknesses of steel tube with two replicates for each wall-thickness. Based on the test, the influencing law of steel ratio on the failure, loading performances and ductility was analyzed, and the improving effect of reinforcement on the behavior of R-RACFSTs was confirmed, and the finite element (FE) model was developed, and the FE simulations were then performed considering the coupling effect between the wall-thickness of steel tube, reinforcement and strength of RAC. The strength prediction equations of CFSTs from codes such as T/CECS 625, GBT51446-2021, GB50936-2014, ANSI/AISC A360-16, AIJ, Eurocode 4 and AS/NZS 5100.6 were studied and their applicability to RACFSTs was confirmed. Meanwhile, novel equations for predicting the strength of R-RACFSTs were proposed and verified. The results demonstrate that: R-RACFST makes it possible to fill RAC with 100% RCA; when combined with an appropriate amount of reinforcement, R-RACFSTs with thinner steel tube performs as well or better than RACFSTs with thicker steel tube; reasonable ranges of steel ratio and confinement index for R-RACFSTs are recommended as 6.2%∼12.8% and 0.78 ∼ 1.53, respectively; the proposed equations are accurate and reliable, and can be applied to design the load bearing capacity of axially loaded R-RACFSTs.

Numerical evaluation of axial compressive behavior of hollow concrete columns reinforced with GFRP bars and spirals

AbstractWith the advancement in the concrete technology, the application of precast concrete elements in the buildings and road infrastructures is increasing very rapidly. One of such applications is the use of precast hollow concrete elements in the bridge construction. As the conventional steel reinforcement is highly susceptible to corrosion, the use of non‐corrosive reinforcement in precast hollow concrete piers and piles of bridges could be a good option for the durability of bridge structures., In this regard, hollow concrete columns reinforced with fiber‐reinforced polymer (FRP) have been considered as a potential solution to overcome the structural deterioration due to corrosion. In the past, limited studies have been carried out on hollow concrete columns reinforced with FRP, consequently, the behavior of such columns is not fully understood. Therefore, to comprehensively evaluate the behavior of hollow concrete columns for various design parameters, a finite element model (FEM) was developed in this study using the commercial tool “Abaqus”. The model was developed and verified based on the experimental results of studies conducted by two independent research groups on circular concrete columns. The proposed model well predicted the peak loads with an error less than 10% and the failure modes of the tested columns. The verified constitutive relation and establishing method were further employed to conduct parametric evaluations to observe the influence of different parameters, such as inner‐to‐outer diameter ratio, longitudinal reinforcement ratio, lateral reinforcement ratio, and concrete strength, on the behavior of hollow concrete columns. Parametric analyses show that reduced inner‐to‐outer diameter ratio and larger longitudinal or lateral reinforcement may lead to higher peak load and confined concrete strength. Finally, based on the experimental and FEM evaluations, the strength prediction equations were developed for the analysis and design of hollow concrete columns reinforced with GFRP bars.

Study of the Applicability of the Vyalov Long-Term Strength Prediction Equation under Freezing and Thawing Conditions

In order to determine the appropriate utilization conditions of the Vyalov long-term strength prediction equation, this study selected three soil samples from the loess region. These samples were subjected to varying numbers of freeze–thaw cycles, namely 0, 4, 6, 8, 10, 50, and 100 cycles. Subsequently, post-test soil samples underwent spherical template indenter press-in tests and grain size determinations. The experimental outcomes demonstrated that the Vyalov long-term strength prediction equation accurately reflected the long-term strength variations of frozen loess after 10 freeze–thaw cycles. A further analysis revealed that the stability of the soil samples’ grain composition played a vital role in ensuring the accuracy of the prediction equation. Notably, a highly significant positive correlation was observed between the silt content of the soil samples and the prediction equation parameter β. Moreover, employing the Vyalov long-term strength prediction equation after 10 freeze–thaw cycles yielded prediction results consistent with the freeze–thaw cycles–time analogy method for durations of 10, 20, and 30 years. This study is beneficial for the construction and operation of projects in loess areas.

Bond strength characteristics of high strength alkali activated slag concrete mixes

Bond characteristics are influenced by several factors such as concrete compressive strength, type, diameter, and embedment length of the bar and confinement of concrete. Herein, an attempt has been made to evaluate the bond strength characteristics of a new class of high-strength, flowable, alkali activated slag concrete mixes made using the industrial by-products from iron and steel industries. Such evaluations are made using the results of direct pull out tests where again, the bond stress – slip behaviour of the trial mixes at different ages are also studied. GGBFS was used as the principal binder along with fine amorphous quartz powder in the development of the present class of high strength, flowable AASC mixes. While mixtures of steel slag sand and quartz sand were used as the fine aggregates, 12.5 mm down electric-arc furnace slag aggregates constituted the coarse aggregate fractions in all these mixes. The alkaline solutions used consisted of mixtures of specified amounts of sodium hydroxide flakes dissolved in the calculated quantity of water pre-mixed with the liquid sodium silicate solution. The experimental study was planned based on Taguchi’s design of experiments methodology. A set of AASC mixes were developed and evaluated for their workability characteristics along with compressive strengths at the ages of 3, 28, 56 and 90 days. Bond strength characteristics of a set of nine of such mixes were evaluated in an initial calibration phase. Strength prediction equations were then derived based on those initial results, the predictive capability of which were then assessed and ascertained with actual results of experiments on a set of six new mixes, in the prediction phase. Further better bond stress-slip behavior, with higher bond strength values, varying in the range of 12–14 MPa as compared to control OPC based reference concrete mix were obtained for the AASC mixes.

Lower extremity muscle strength equation of older adults assessed by Five Time Sit to Stand Test (FTSST).

The decline in lower limb muscle strength, one of the risk factors for falling in the older adults, puts older persons at an increased risk of falling. The assessment of the lower limb muscle strength is very important. The purpose of this study was to construct the equation for predicting knee extensor muscle strength based on demographic data and the results of the Five-Time Sit-to-Stand Test (FTSST). A total of 121 healthy elders (mean age ) were asked to complete the FTSST and submit the demographic information. By using a stationary push-pull dynamometer, the knee extensor strength of each participant was assessed. The multiple regression analysis was used to explore knee extensor strength prediction equation. The findings demonstrated that the knee extensor strength equation was developed using variables obtained from gender, weight, and time to complete the FTSST. The equation was found to have a high correlation () and 70.1% estimation power. Its formula was as follows: Knee extensor (gender; or ) 0.189 (weight) - 2.617 (time to complete the FTSST). However, there was an estimating error in this equation of 4.72 kg. The determining factors influencing knee extensor strength, which can be utilized to estimate the strength in elderly individuals, are demographic variables including gender, weight, and the time taken to complete the FTSST.

Optimum reinforcement ratio of axially loaded reinforced concrete-filled square steel tube column

For the purpose of clarifying the influencing mechanisms of the longitudinal reinforcement on loading performances of Reinforced Concrete-Filled Square Steel Tube (R-CFSST) short columns under axial load, experimental and numerical studies were performed. Setting the longitudinal reinforcement ratio as parameter, ten R-CFSSTs with five different ratios and three Concrete-Filled Square Steel Tube (CFSST) specimens for comparison were fabricated and tested. Based on the test, the influencing law of longitudinal reinforcement on failure, loading behavior, stiffness, peak load, composite efficiency, ductility and stress state of steel tube of R-CFSSTs were theoretically investigated. A novel material model and simulation method for concrete core was proposed and verified against the test, and thereafter 32 model specimens with four wall-thicknesses of steel tube coupling with eight reinforcement ratios were simulated. The strength prediction equations from ANSI/AISC A360–16, Eurocode 4 and AS/NZS 5100.6 and GB 50936–2014 were studied, modified and compared each other, and based on the test and simulation results, novel equations were proposed and validated against the experiment. The results demonstrate followings: longitudinal reinforcement significantly impacts the behavior of R-CFSSTs as the steel tube does, and thus it is recommended to configure reinforcements in CFSST for the improved performances; proper ratios of longitudinal reinforcement enable the R-CFSSTs to acquire better balance between performance and construction cost, and a range for the optimum ratios is recommended between 1.0% and 3.2%, regardless of wall-thickness of steel tube; the proposed equations are recommended for more accurate and stable prediction of load bearing capacity of R-CFSSTs.

Residual Compressive Strength Prediction Model for Concrete Subject to High Temperatures Using Ultrasonic Pulse Velocity.

This study measured and analyzed the mechanical properties of normal aggregate concrete (NC) and lightweight aggregate concrete (LC) subjected to high temperatures. The target temperature was set to 100, 200, 300, 500, and 700 °C, and W/C was set to 0.41, 0.33 and 0.28 to evaluate high temperature properties at various intensities. Measurement parameters included mass loss, compressive strength, ultrasonic pulse velocity (UPV), and elastic modulus. We compared the residual mechanical properties between the target and preheating temperatures (20 °C) and then analyzed the correlation between UPV and compressive strength. According to the research findings, after exposure to high temperatures, LC demonstrated a higher mass reduction rate than NC at all levels and exhibited higher residual mechanical properties. The results of analyzing the correlation between compressive strength and UPV for concrete subjected high temperatures were very different from the compressive strength prediction equation previous proposed at room temperature, and the error range of the residual strength prediction equation considering W/C was reduced.

Axial compressive behaviour of thin-walled composite columns comprise high-strength cold-formed steel and PE-ECC

A new form of thin-walled composite columns, made of high-strength cold-formed steel (CFS) open sections and thin layers of engineered cementitious composites (ECC), is presented in this paper. The axial behaviour of columns with slenderness ratios (le/r) ranging between 10.08 and 13.86 under concentric loads were experimentally investigated. Twelve column specimens were divided into four groups of bare CFS columns, plain ECC columns, composite columns with SupaCee sections, and composite columns with Lipped-Cee sections. A specific ECC mixture with three PE-fibre contents: 0.75%, 1.75%, and 2.25% by mix volume, was placed in the tested columns in two thin thicknesses of 16.0 mm and 26.0 mm. Additionally, a high-strength concrete (HSC) mixture was utilised in two test columns for comparison with ECC. The results revealed that the composite CFS/ECC columns exhibited enhanced axial compressive capacities up to 2.79 times that of the bare CFS columns. The ductility indices and compressive toughness of the composite CFS/ECC columns were improved to 1.56 and 3.85 times those of the bare CFS columns, respectively. Strength prediction equations were developed based on the experimental observations to estimate the axial compressive capacity of composite CFS/ECC columns susceptible to local buckling.