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• OCR-detected characters or words in an image require line segmentation to reunite into word or sentence. • Projection based line segmentation cannot be applied to Chinese historical texts. • Columns in Chinese historical texts exhibit a sub-divided column format. • Adjacent character detection (ACD) algorithm can deal with the unique column structure. • Performance of ACD algorithm as a post-processing of OCR is discussed. In recent times, the advent of AI-based optical character recognition (OCR) has garnered significant attention in the realm of digital text conversion. However, it is imperative to note that OCR solely identifies individual characters or words, and lacks the ability to reunite them into cohesive units such as words or sentences. Consequently, the manual sorting of them to establish the appropriate reading order has emerged as a bottleneck. In this paper, we present an algorithm termed adjacent character detection (ACD), designed to serve as a post-processing of OCR, facilitating automatic digital text conversion. The algorithm involves line segmentation through a quad-ACD scan (up-down-down-up), allowing it to consecutively discern characters within a column based on their adjacency relations. Conventional projection profile analyses have struggled to effectively partition the distinct internal structure of Chinese historical text, where two annotation columns often subdivide from a single body column. In contrast, our ACD algorithm employs an approach, reuniting adjacent characters rather than fragmenting the entire text into isolated entities. Additionally, ACD algorithm enabled body/annotation classification for OCR-detected characters based on the pattern analysis of its quad scan. This cumulative information empowers the conversion of digital text in a desired reading order. To assess the efficacy of the proposed algorithm, a set of ground-truth OCR result was subjected to rigorous testing, culminating in a reading order accuracy of 98.6%. Noteworthy robustness was also demonstrated in the face of misaligned columns, experimentally induced by applying tilt, warp, and wavy noises to the original digital images. Lastly, the algorithm was integrated with two pre-developed OCR models, resulting in a reading order accuracy of 97.7%. [Display omitted] [ABSTRACT FROM AUTHOR]

Accurate identification of the failure modes of Reinforced Concrete (RC) columns based on the design parameters of the structural members is critical for earthquake-resistant design and safety evaluation of existing structures. Existing identification methods have some problems, such as high cost, incomplete consideration of influencing factors, and low precision or recall in identifying shear or flexural-shear failure. In this paper, the main factors for the failure modes of RC columns are first analyzed and studied. Then, the problem of class imbalance in data samples is investigated. To identify the failure modes of RC columns, oversampling of data (BSB-FMC), model ensembling (RFB-FMC), cost-sensitive learning (CSB-FMC) and a fusion model of three strategies (BSFCB-FMC) are proposed. And finally, the SHapley Additive exPlanations (SHAP) method is used to provide a better interpretation of the designed model. The results show that the developed strategies can improve the accuracy of identifying the failure modes of RC columns compared to the models using a single Artificial Neural Network (ANN), a Support Vector Machine (SVM), a Random Forest (RF), and Adaptive Boosting (AdaBoost). The overall accuracy of the developed BSFCB-FMC model reaches 97%, and the precision and recall for the three failure modes are both above 90%. The designed model provides a solution for fast, accurate and cost-effective identification of the failure modes of RC columns. • We develop the models for identifying the failure modes of RC columns considering class imbalance problem. • The BSFCB-FMC model is developed by considering data oversampling, model ensembling, and cost-sensitive learning. • The designed model provides engineers with an interpretable, fast and stable model for identifying failure modes. [ABSTRACT FROM AUTHOR]

• Terrestrial laser scanning of the column of Hera Lacinia Temple and its surroundings. • Polygonal modelling and survey of the column and basement. • CFD analysis of the column, subjected to the main winds in the area. The study presents the results of a multidisciplinary research that integrates terrestrial laser scanning (TLS) and computational fluid dynamics (CFD) to document and analyse an archaeological asset subject to natural hazards. The experimentation was conducted on the surviving column of the temple of Hera Lacinia, located in Capo Colonna near Crotone (Italy). The column, the fragments of the crepidoma and of the foundation constitute the most visible remains of the peripteral Doric temple (second quarter of the 5th century B.C.), belonging to the most important sanctuary of Magna Graecia. The temple, the sanctuary and the other ancient buildings, which are in the area of the Capo Colonna promontory, were destroyed over the centuries to obtain construction material. Today the column and the remains of the temple are located inside the National Archaeological Park of Capo Colonna, protected from human action, but subject to natural phenomena which are dangerous or potentially dangerous in the long term. The wind exerts a constant erosion of the surface of the column and wear of the lower part of the shaft due to the continuous oscillations to which it is subjected; moreover, the wind thrust could add up to a possible seismic action. On the other hand, the geomorphological evolution of the promontory (coastal erosion and subsidence) causes the coastline to recede, and is responsible for landslides affecting the column-basement system. Starting from the point cloud acquired by the TLS, a mesh of the column, basement and surrounding terrain was created, aimed both at documentation, graphic analysis and CFD. The survey enabled the description of the current state of the column-basement system, documenting and measuring the shapes of the column, as well as the different inclinations of the individual parts caused by instability of the ground. Furthermore, the CFD model of the Hera Lacinia column was developed. The model is based on the three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations with the k-ε closure turbulence model. The oncoming wind was modelled according to the results obtained from 70 years of statistics analysis (from 1950–2021) of wind hourly data (streamwise and spanwise components). The interaction between wind flow and the Hera Lacinia column geometry shows very complex phenomenona. The adopted numerical model was able to simulate correctly the main phenomena involved such as the flow separation occurring around the column as well as the wake behind it. Particular attention was paid to investigating the most damaged areas of the column, identified by analysing recent images of the column, where the values of the time-averaged drag and lift forces were obtained. In order to obtain the erosion-based damage prediction future research will focus on the analysis of air flow erosion of the Hera-Lacinia column, starting from the measurements in situ of the main air characteristics and using the latter as the fluid for the numerical simulation, and by also considering different values of wind speed and directions. [ABSTRACT FROM AUTHOR]

Arsenic contamination, at lower concentrations (up to 500 µg L-1), is an important environmental concern but has received limited attention. Adsorption capacities, kinetics and equilibrium phenomena are concentration dependent. Previous studies focused on higher arsenic concentrations associated with industrial discharges, failing to address arsenic contamination in drinking water. This study investigates arsenic adsorption using Eleocharis dulcis biochar loaded with CuO (EDB-CuO) at lower concentrations (up to 500 µg L-1). The synthesized biochar was characterized by X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Point of Zero Charge (PZC) and Scanning Electron Microscopy (SEM). Batch adsorption experiments were conducted, varying time, concentration, temperature and pH. Results indicated that increasing temperature positively influenced arsenic adsorption onto EDB-CuO, while pH had an opposite effect, with maximum adsorption occurring at lower pH levels (2−3). The equilibrium time was established at 240 min for arsenate adsorption. Kinetic data best fitted the Ho and McKay's plot and the Langmuir model calculated a maximum adsorption capacity of 26.1 mg g-1. Thermodynamic parameters, including enthalpy, entropy and activation energy, supported the conclusion that the arsenate adsorption process was spontaneous and chemisorptive. Column studies demonstrated remarkable adsorption retention performance (>88%) of the composite for arsenate removal over 8 h. Similarly, a fixed-bed column experiment was conducted to study the adsorption mechanism of arsenate on EDB-CuO by employing the Bohart-Adams, Thomas, and Clark models. The Clark model was found to best describe the arsenate removal mechanism. Additionally, recycling studies of arsenate from the loaded EDB-CuO surface were investigated up to 4 adsorption-desorption cycles. A small decrease was observed in the second cycle, from 92.06% removal to 85.15%, which further decreased in the third cycle (62.18%), and even more in the fourth cycle (30.8%). • Efficient arsenate adsorption onto Eleocharis dulcis biochar composite with copper. • Mechanism showing the applicability of Langmuir isotherms to the adsorption data. • Kinetics is explained by Ho and Mckay's plot. • Remarkable retention capacity of the composite in column experiment. [ABSTRACT FROM AUTHOR]

We study the computational complexity of multi-stage robust optimization problems. Such problems are formulated with alternating min/max quantifiers and therefore naturally fall into a higher stage of the polynomial hierarchy. Despite this, almost no hardness results with respect to the polynomial hierarchy are known. In this work, we examine the hardness of robust two-stage adjustable and robust recoverable optimization with budgeted uncertainty sets. Our main technical contribution is the introduction of a technique tailored to prove Σ 3 p -hardness of such problems. We highlight a difference between continuous and discrete budgeted uncertainty: In the discrete case, indeed a wide range of problems becomes complete for the third stage of the polynomial hierarchy; in particular, this applies to the TSP, independent set, and vertex cover problems. However, in the continuous case this does not happen and problems remain in the first stage of the hierarchy. Finally, if we allow the uncertainty to not only affect the objective, but also multiple constraints, then this distinction disappears and even in the continuous case we encounter hardness for the third stage of the hierarchy. This shows that even robust problems which are already NP-complete can still exhibit a significant difference in computational complexity between column-wise and row-wise uncertainty. [ABSTRACT FROM AUTHOR]

This study investigated the impact of openings on the punching shear strength of 'non-coarse aggregate acrylic polymer concrete' (APC) slabs. Twelve specimens representing scaled models of a flat, with different parameters such as concrete type, opening size, and distance from the column edge. The specimens were divided into five groups, including a control group of normal strength concrete and APC specimen without openings, as well as APC specimens with various opening sizes and distances, along with APC enhancement specimens. Experimental results were validated using Abaqus finite element software, demonstrating good agreement between the experimental and simulated outcomes. The analysis encompassed several aspects, including load-deflection response, ultimate loading capacity, post-ultimate loading capacity, failure patterns, and strain distribution. The absence of coarse aggregate in APC significantly impacted its shear resistance, leading to a reduction in internal friction. Compared to ordinary concrete slabs, the ultimate capacity of APC slabs without openings was approximately 36% lower. The presence of two openings adjacent to the column further decreased the ultimate capacity by approximately 33%. The size and distance of the openings played a crucial role in determining the ultimate capacity of APC slabs. Notably, the APC specimens exceeded the design ultimate load calculated by Egyptian Code of Practice (ECP-203-2020) and ACI-318-19 codes by approximately 1.4 and 1.6, respectively. However, the study advises against relying solely on APC in shear-sensitive constructions without integrating additional enhancements for shear resistance, as the results indicate a significant reduction in the shear resistance compared to ordinary concrete slabs. [ABSTRACT FROM AUTHOR]

The study was conducted on a laboratory scale and the main objective was to evaluate the feasibility of using bentonite and calcium alginate-based granules to adsorb pollutants from rainwater in a columnar system. Therefore, in this study, the fine powder of clay materials was mixed with calcium alginate to obtain capsules that can be easily separated and recovered. These granular sorbents were found to be a new and inexpensive solution for removing heavy metals from water. On the basis of the pollutant adsorption study, the sorption capacities of the adsorbent and bed, adsorption rates, and bed breakthrough time were determined. Characterisation of the structural features of the granules using modern observational and spectroscopic techniques, that is, scanning electron microscopy, Brunauer-Emmett-Teller, and Fourier-transform infrared spectroscopy, was also an important part of the study. The aim of the study was to conduct the adsorption process under dynamic conditions to determine the efficiency of removing copper and lead ions from rainwater. Static adsorption showed a high percentage of copper removal of 72.75% and lead removal of 84.5% for a dose of 2.0 g/L. The column adsorption system showed a high removal rate. Regeneration showed a high efficiency of copper and lead adsorption. In the fourth cycle in the case of Cu(II), 60%, column 2 - 52.5%, column 3 - 30%, for Pb(II) for column 1 - 73%, column 2 - 76%, column 3 - 50% were obtained. [ABSTRACT FROM AUTHOR]

For any structures, Reinforced concrete (RC) columns are the utmost carping members. RC columns jacketed with CFRP membrane enhance resistance, deformation aptitude, and the auspicious confining impacts. Sundry scrutiny has been implemented about circular columns wrapping or veiled with CFRP layers. This scrutiny will manifest about Genetic Programming (GP) and Artificial Neural Networks (ANN) as soft computing models, mobbing exploited to ascertain the lateral confinement coefficient (K s) valuate of RC circular columns jacketed with CFRP membrane. For the purpose to ascertain K s value, manipulate the corresponding ambit such as the diameter of the column (b), column length (L), thickness layer of CFRP (t w), the elastic modulus of CFRP membrane (E f) along with the compressive strength of unconfined concrete (f cc). Total collection of 142 datasets for the RC circular column was employed to decipher the prediction of K s. Various statistical metrics (R2 = 0.933; RMSE = 0.054; NMBE = -0.001) compared with the ANN model and exhibits the superiority of GP in predicting the K s. Taylor diagram and Rank analysis were also carried out in this article for justification. The lucidity of the GP machine enlightenment model overtures a greater sensible and exact prediction of K s value for RC circular columns in accordance with versatile loading conditions. [ABSTRACT FROM AUTHOR]

The evaluation of the confining pressure between steel and concrete is a complex yet important issue for concrete-filled steel tube (CFT) columns. The previous study is mainly based on the finite element model (FEM) because the confining pressure cannot be measured directly in the tests. Besides, the proposed approaches to calculating the bearing capacity of CFT columns and confining pressure varied significantly as a result of the different simplification. The neural network can simulate the complex problems quickly and accurately based on the proper training and validation. This study investigates the bearing capacity of CFT columns and the confining pressure of concrete based on a newly established experimental database and the artificial neural network (ANN) models. The results can be obtained from five primary parameters of rectangular CFT columns using the ANN models. The obtained bearing capacity and confining pressure from ANN models is compared and validated with that presented in the previous literatures. The parametric studies are performed to evaluate the bearing capacity and confining pressure with the variations of the dimensions and the material strength. The result could contribute to evaluate the interaction between the steel tube and infill concrete and its effect on the bearing capacity of rectangular CFT column. [ABSTRACT FROM AUTHOR]

Reactive Dividing Wall Column (RDWC) modelling has attracted significant attention in recent years because simulations of processes containing such columns have demonstrated the potential for significant savings in energy and capital cost. Most modelling of these columns involves decomposing RDWCs into a thermodynamically equivalent flowsheet of reactive and non-reactive column sections in a sequential modular process simulation package. Such simulations of (R)DWCs can be time consuming to create and difficult to converge. It has been suggested that equation-oriented solvers can have superior numerical performance. Here, we use a CAPE-OPEN compliant equation-based parallel column model (PCM) that enables the rapid modelling of an RDWC as a single self-contained unit. Some conventionally modelled RDWCs from the literature are reproduced with the PCM to demonstrate its validity and excellent numerical performance. The ease and rapidity with which different RDWC configurations can be created is a significant advantage of our PCM. [Display omitted] • We describe an equation-oriented rate-based parallel column model for reactive distillation in Dividing Wall Columns. • The model can simulate DWCs of arbitrary configuration. • Model is easy to set up and rapid in execution. • Model is in excellent agreement with results of prior work. [ABSTRACT FROM AUTHOR]

This study investigates the stress-state- and strain-rate-dependent behavior of CeramTec ALOTEC 98% alumina ( Al 2 O 3 ) ceramic through experimentally validated finite element (FE) modeling. As the constitutive material model, a rate-dependent viscosity-regularized phenomenological model (JH2-V model) was implemented through a VUMAT subroutine in ABAQUS software. The FE model was informed and validated with the data for indirect tension and compression–shear tests under dynamic rates both quantitatively (i.e., stress–strain histories and lateral strain–axial strain curves) and qualitatively (i.e., manifestation and accumulation of damage). The validated model was leveraged to study the effect of the JH2-V model regularization parameters, mesh sensitivity, and bulking across different stress states. Additionally, by modeling the compression–shear specimen with different angles, the effect of shear on the material response was quantitatively investigated through the definition of a volumetric average damage parameter and shear strain history. Altogether, the outcomes of this study have implications for the computational design and development of ceramic-based structures in higher-scale applications (e.g., impact). [ABSTRACT FROM AUTHOR]

This paper presents experimental and numerical investigations of the seismic performance of a novel self-centering (SC) hollow-core (HC) fiber-reinforced polymer (FRP)-concrete-steel (SC-HC-FCS) bridge column. This new structure is fabricated by mounting external energy dissipators (ED) and applying unbonded post-tensioned (PT) basalt FRP (BFRP) tendon to the conventional HC-FCS column that consists of an outer FRP tube and an inner steel tube, with the space between filled with concrete. The SC-HC-FCS column combines the advantages of accelerated bridge construction and self-centering. The effects of the initial prestress force values and the configuration of the energy-dissipated aluminum bar on the column performance are studied. Based on the experimental and numerical results, it is found that the proposed SC-HC-FCS column shows adequate self-centering and energy dissipation capacities. However, it is required to properly select the configuration and material properties of the aluminum bar as energy dissipators to further refine the seismic resistance of the SC-HC-FCS column. [ABSTRACT FROM AUTHOR]

Ice is a readily available and renewable resource in cold regions, which offers potential as a low-cost construction material. Nevertheless, the relatively low strength and high brittleness limit its wider applicability. Given the confinement effectiveness enabled by fiber-reinforced polymer (FRP), this study investigated the compressive behavior of composite columns consisting of ice cores encased in FRP tubes. Uniaxial compression tests were performed on ice cylinders confined by different FRP (including carbon, glass, and basalt FRP) tubes with varying thicknesses. The experimental findings revealed a distinct bilinear compressive response in the confined ice, exhibiting a continuous upward trend. The compressive strength of confined ice could be 2.9–8.4 times that of unconfined ice. Considering its greater homogeneity than concrete, ice allowed the FRP to achieve a higher utilization rate, resulting in larger hoop rupture strains. Moreover, the higher Poisson's ratio of ice, compared to concrete, led to earlier activation of lateral FRP confinement. To predict the compressive behavior of ice confined by three different FRP tubes (including axial compression and dilation responses), a unified design-oriented model was developed with favorable performance. • Behavior of ice cylinders confined by three types of FRP tubes was investigated. • Compressive strength of confined ice could be 2.9–8.4 times that of unconfined ice. • FRP had higher utilization rate in FRP-confined ice than that in confined concrete. • Developed model effectively captured the primary characteristics of confined ice. [ABSTRACT FROM AUTHOR]

High-performance concrete-filled steel tube (CFST) members consisting of high-strength steel and ultra-high performance concrete (UHPC) are more and more widely applied in modern engineering structures. These structures/structural components may suffer from axial impact loading during its life cycle such as impact induced by the collapse of top-level floors. However, the design and evaluation methods for axial impact resistance remain unclear for these structures. This paper presented a systematic study on both the impact and post-impact resistances of high-performance CFST members subjected to axial impact. A database of CFST members subjected to axial impact was first compiled, and a finite element (FE) model was established and verified by the test results from the compiled database. The effects of key parameters on the impact resistances and residual capacity of square UHPC-filled high-strength steel tubes under axial impact were clarified. By employing 420 FE models of square CFST columns subjected to axial impact with random parameters, equations for predicting the maximum axial displacement under axial impact and axial residual bearing capacity after axial impact that are suitable for conventional and high-performance CFST columns (f y ≤ 960 MPa and f cu ≤ 200 MPa) were developed with reasonable accuracy. Finally, a maximum deformation limit was recommended for CFST components subjected to axial impact, which provides a reference for anti-impact design and evaluation for general high-performance CFST members. • An FE model of high-performance CFST members subjected to axial impact is established and benchmarked. • The effects of key parameters on the impact resistances and residual capacity were clarified. • Equations for predicting the maximum axial displacement and axial residual bearing capacity after axial impact were developed. • A maximum deformation limit was recommended for CFST components subjected to axial impact. [ABSTRACT FROM AUTHOR]

To investigate the fire resistance of L-section fireproof board and thin concrete encased steel (L-FBTCES) column, four columns were tested under constant axial compression and ISO-834 standard fire, varying the load ratio and concrete encasement thickness. The failure modes, thermal response, deformation response, and fire resistance time were obtained. The thermal response curve of the steel exhibited three stages, and the maximum temperature of the steel was below 600°C during the test. The fire resistance time for all specimens exceeded 120 minutes. The resistance time decreased with the increase of the load ratio and slightly increased with the increase of the concrete encasement. The thermo-mechanical coupling models were established, and the numerical parametrical analysis was conducted. Based on the existing specifications for composite columns and considering the adjusted load ratio and fireproof board thickness, a modified calculation method for L-FBTCES columns was proposed and validated by the numerical analysis results. • A novel L-section fireproof board and thin concrete encased steel column was proposed. • Four specimens were analyzed via fire test and finite element analysis. • Failure modes, thermal and deformation response of column were analyzed. • Parameter analysis was performed for the fire resistance performance of columns. • A revised calculation method of fire resistance times for columns was proposed and verified. [ABSTRACT FROM AUTHOR]

• TGAN can efficiently enrich the database. • MFO-ET model is developed for outer circular CFRP-strengthened CFST columns. • The MFO-ET model outperforms empirical models. • Reliability analysis is conducted for safety level evaluation. • Web application is developed for ultimate strength prediction with less effort. This study develops a novel hybrid machine learning model to estimate the ultimate axial strength and conduct a reliability analysis for outer circular carbon fiber-reinforced polymer (CFRP)-strengthened concrete-filled steel tube (CFST) columns. The experimental datasets are collected and enriched using the conditional tabular generative adversarial network (CTGAN). The column length, the steel properties (cross-section diameter, thickness, and yield strength), the CFRP properties (thickness, tensile strength, and elastic modulus), and concrete strength are selected as input variables to develop the Extra Trees (ET) model hybridized with Moth-Flame Optimization (MFO) algorithm for the ultimate axial strength estimation. The results reveal that the CTGAN can efficiently capture the actual data distribution of CFRP-strengthened CFST columns and the developed hybrid MFO-ET model can accurately predict the ultimate axial strength with a high accuracy (R2 of 0.985, A10 of 0.867, RMSE of 182.810 kN, and MAE of 124.534 kN) based on the synthetic database. In addition, compared with the best empirical model, the MFO-ET model increases the R2 by (6.78% and 13.48%) and A10 by (108.19% and 122.88%) and reduces the RMSE by (68.19% and 66.24%) and MAE by (71.33% and 68.48%) based on real and synthetic databases, respectively. Notably, a reliability analysis is performed to evaluate the safety of the developed MFO-ET model using Monte Carlo Simulation (MCS). Finally, a web application tool is created to make the developed MFO-ET model easier for users to design practical applications. [ABSTRACT FROM AUTHOR]

A thin-walled square glazed hollow beads recycled aggregate concrete-filled double-skin steel tubular (GRCFDST) column with a circular hollow section as the inner tube is introduced as a new form of a composite column in the paper. To investigate the axial compressive behavior of thin-walled square GRCFDST short columns with a 100 % replacement rate of recycled coarse aggregate, axial compression tests and numerical analyses were conducted on twelve specimens in this study. The deformation characteristics and failure mechanisms of the specimens were analyzed, along with the influence of different parameters on the axial compressive behavior, including steel tube width-to-thickness ratios (64−88), hollow ratios(0–0.35), and glazed hollow beads (GHB) dosages(80 %∼100 %) in the recycled aggregate concrete. Experimental results indicate that the failure modes of glazed hollow beads recycled aggregate concrete(GHBRC) composite specimens are essentially consistent with those of natural concrete(GHBNC) composite specimens, all short columns exhibited good ductile behaviour; Ultimate strength of the specimens increased with the rise in steel tube width-to-thickness ratios and hollow ratios, but decreased as the dosages of GHB increased. Ductility index increased with higher hollow ratios and GHB dosages, but decreased with larger steel tube width-to-thickness ratios. The finite element analysis results showed good agreement with the experimental results.Additionally, a comparison of the calculated results from different design codes with the experimental values indicated that incorporating a confinement effect coefficient significantly enhances calculation accuracy. Finally, the simplified design formula were proposed to calculate the ultimate strength of thin-walled square GRCFDST short columns under axial compression. • Experimental and numerical investigation of thin-walled square GRCFDST short columns. • GRCFDST short columns with a 100 % replacement rate of recycled coarse aggregate. • Width-to-thickness and hollow ratios significantly affect ultimate strength and ductility. • Simplified formulae is proposed to calculate ultimate strength of GRCFDST short columns. [ABSTRACT FROM AUTHOR]

Titanium-clad (TC) bimetallic steel is a high-performance laminated steel with excellent corrosion resistance and mechanical properties as well as acceptable cost, which can be applied in ocean and offshore environments. This paper aims to study the axial compression behaviour of circular concrete-filled titanium-clad bimetallic steel tubular (CFTCBST) stub columns through experimental and numerical investigations. A total of seven specimens are manufactured and subjected to axial compression loading, with various geometric dimensions and concrete strengths. A three-dimensional finite element (FE) model is developed and validated against the experimental results to further study the axial compression behaviour of circular CFTCBST stub columns herein. The parametric study is carried out using the verified FE modelling approach with four major parameters considered, including the concrete strength, the substrate steel grade, the clad ratio, and the diameter-to-thickness ratio. Finally, the applicability of existing design methods for predicting the ultimate bearing capacity of circular CFTCBST stub columns is further analysed through comparisons with the FE results, and it is found that the Eurocode EN 1994–1–1 has the most accurate prediction that can be extended to predict the capacity of circular CFTCBST stub columns. • Circular concrete-filled titanium-clad bimetallic steel tubes are tested. • The finite element (FE) models are developed and validated. • Effects of critical parameters are clarified in depth by verified FE models. • The design methods adapted from EN 1994–1–1 are proposed. [ABSTRACT FROM AUTHOR]

In this paper, a new type of composite sections, which are composed of one outer square steel tube, four inner circular or square steel tubes and filled concrete, four-opening concrete filled sandwich steel tube (FCFSST), is first developed. To assess seismic response of typical beam-columns, the tests under axial compression and lateral cyclic loading were conducted on ten FCFSST specimens and one counterpart concrete filled steel tube (CFST) specimen. Effect of several key variables, including void ratio (χ), axial compression level (n), nominal cross-sectional steel ratio (α n) and sectional type of inner tubes, on the seismic performance of representative FCFSST specimens was investigated in detail. The experimental observations show that, the failure modes of FCFSST beam-column specimens include outward local buckling (LB) and fracture following LB of outer tube, inward LB and fracture following LB of inner tubes and crushing/cracking of sandwich concrete, and generally n and α n are the controlling factor for the failure of outer tube, whilst χ and sectional type mainly affect the failure of inner tubes. For the FCFSST specimens, a lower n and a larger α n result in a superior plumpness of the hysteretic curve, a slower stiffness degradation, a higher energy dissipation, and a better ductility, and the influence of n and α n on key factors is more significant than that of χ. Additionally, in comparison with the reference CFST specimen, the FCFSST specimens show a 20.8 % increase in lateral capacity, a 5.0–9.5 % increase in cross-sectional flexural stiffness, and a 11.7–21.7 % increase in energy dissipation, while presenting a 22.7–25.2 % reduction in ductility coefficient and an 8.2–20.1 % reduction in ultimate drift, respectively. Finally, the approaches in the existing design specifications of composite structures were used to predict flexural capacity and cross-sectional flexural stiffness of FCFSST beam-columns under lateral cyclic loading, and the results indicate that the approach in T/CCES can precisely and safely predict the flexural capacity by considering the increased steel yield strength under cyclic loading, whereas the approach in AISC can offer an accurate prediction for the cross-sectional flexural stiffness. • A novel composite section, called four-opening concrete filled sandwich steel tube (FCFSST), was proposed. • Tests on typical FCFSST beam-columns under axial compression and lateral cyclic loading was conducted. • Effect of key variables on the seismic performance of typical FCFSST beam-column specimens was investigated. • Applicability of existing approaches in predicting mechanical indexes of FCFSST beam-columns was evaluated. [ABSTRACT FROM AUTHOR]

Elliptical FRP–concrete–steel double-skin tubular column (EDSTC) is a promising option especially when dissimilar bending stiffness is required along two directions. Although monotonic behavior has been reported, relevant research on its behavior under cyclic compression is not yet available. To bridge this gap, experimental investigations were implemented to clarify the fundamental characteristics of EDSTC with different loading patterns, aspect ratios, and FRP thicknesses. The results showed that EDSTC had favorable axial performance under different loading modes. Compared with monotonic counterpart, the unloading/reloading compression cycles had limited effects on confined concrete strength and corresponding deformability. By contrast, FRP hoop rupture strain of cyclically loaded columns was reduced by 10% due to possible damage accumulation. The larger aspect ratio led to more severe stress deterioration in confined concrete, but the linear relationship between plastic strains and unloading strains was marginally affected by aspect ratio. Moreover, at the termination of unloading, compressive stress might develop in confined concrete to equilibrate possible reversal tensile stress in steel tubes, leading to a shift in cyclic patterns. A refined model for confined concrete in cyclically loaded EDSTC was formulated with favorable performance. • Elliptical FRP-concrete-steel hollow composite columns were cyclically loaded. • FRP hoop rupture strain of cyclically loaded columns was reduced by 10 %. • Reversal tensile stress in internal steel tubes led to a shift in cyclic patterns. • Larger aspect ratio led to more severe stress deterioration in confined concrete. • Developed model effectively captured primary characteristics of cyclic responses. [ABSTRACT FROM AUTHOR]

Prior studies on the parameter sensitivity analysis of the seismic performance of self-centering precast segmental bridge columns (SC-PSBCs), concentrated on parameters like axial compression ratio and shear span ratio, have overlooked other critical factors. This oversight indicates an urgent need for a more systematic and comprehensive sensitivity analysis to uncover the key factors influencing the seismic behavior of SC-PSBCs. The present study conducts a finite element-based sensitivity analysis to scrutinize the influences of various design parameters on the seismic performances of SC-PSBCs. To begin with, a refined finite element model of the SC-PSBC is established and validated using data from cyclic load tests. Utilizing the validated model as a foundation, a systematic exploration is performed on parameters including the strength of energy-dissipating (ED) reinforcement, unbonded length of ED reinforcement, concrete strength, and layout of post-tensioned (PT) tendons, along with nine additional parameters, aiming to uncover their distinct influences on the hysteretic behavior, lateral load-bearing capacity, energy dissipation, and residual displacement of SC-PSBCs. It is found that the energy dissipation exhibits the least sensitivity to parameter changes. Nonetheless, it is markedly influenced by the reinforcement ratio of ED bars, which shows a clear and significant positive correlation. Conversely, the residual displacement is responsive to a multitude of parameters. Notably, the shear span ratio emerges as the most important determinant. An increase in this ratio is associated with a marked decrease in the residual displacement ratio. Furthermore, the results indicate that the unbonded region of ED bars positioned within the foundation reduces the residual displacement without substantially compromising the lateral bearing capacity and energy dissipation capacity. In addition, the PT tendons could be strategically placed at the corners of four sides to maintain a relatively high strength of concrete, which can optimize the seismic performance of SC-PSBCs. Beyond these critical observations, quantitative and qualitative conclusions have been yielded. These findings are instrumental in optimizing the design of SC-PSBCs, offering insights that can enhance the seismic resilience of bridge infrastructure in seismically active regions. • A systematic finite element-based seismic sensitivity analysis of SC-PSBCs. • A series of quantitative and qualitative conclusions are derived. • Numerous recommendations for seismic design of SC-PSBCs are provided. [ABSTRACT FROM AUTHOR]

This paper focuses on the behavior of perfobond (PBL) stiffened DSSC stub columns under eccentric compression. Eccentric compression tests were performed on 12 PBL stiffened DSSC stub columns. Based on the test results, the failure mode, local buckling response, load-displacement curve, ductility, and strain distribution were discussed. The results indicate that all specimens exhibit local buckling before reaching their ultimate load. The buckling waves of DSSC stub columns with PBL stiffeners are multiple, while the buckling wave of the other stub columns is singular. The effect of the PBL stiffeners is reflected in transforming the specimen's buckling from elastic-plastic local buckling to plastic local buckling. In addition, PBL stiffeners significantly improve the ductility of DSSC columns. The axial bearing capacity of the specimen decreases with the increase of eccentricity, and the bending bearing capacity increases with the growth of eccentricity. In addition, in the case of medium eccentricity, the increase in length-width ratio is beneficial to developing plastic capacity. Finally, the effective width method is used to consider local buckling. A simplified N - M curve of the PBL stiffened DSSC stub column under eccentric compression is developed, which provides a conservative and accurate prediction for the test results. • Eccentric compression test of PBL stiffened double-skin sandwich composite (DSSC) stub columns carried out, • Eccentric compression behavior of PBL stiffened DSSC stub columns analysed and discussed. • Prediction method for N - M curve of PBL stiffened DSSC stub columns considering local buckling proposed. [ABSTRACT FROM AUTHOR]

To enhance the axial compression capacity and ductility of high-strength concrete-filled high-strength square steel tubes (HCFHSSTs), the imbedding of high-strength spirals (HSS) within HCFHSSTs is proposed. By varying the thickness and yield strength of the steel tubes, spacing and yield strength of the spirals, and diameter of the spiral confinement, high-strength spiral-confined high-strength concrete-filled high-strength square steel tube (HSS-CHCFHSST) stub columns under axial compression were tested. The experimental results demonstrated that compared with a normal-strength spiral (NSS), the application of a HSS significantly enhances the load-bearing capacity and ductility of HCFHSST stub columns under axial compressive loads. In the testing phase, the HSS exhibited yielding behavior subsequent to the HSS-CHCFHSST stub columns achieving their peak load; this was followed by multiple instances of fracturing. The working mechanism and parameters of the HSS-CHCFHSST stub columns were analyzed numerically. After the peak load, the HSS effectively confined the core concrete, increasing its stress. The HSS-CHCFHSST column exhibited a higher axial compressive capacity and ductility than an equivalent HCFHSST column using a thick tube. Considering the significant contribution of the core concrete confined by HSS to the load-bearing capacity of HSS-CHCFHSST stub columns under axial compressive conditions, a comprehensive equation was formulated for the precise calculation of their axial compression capacity. • HSS-CHCFHSST stub columns under axial compression were tested. • The finite element model of HSS-CHCFHSST stub columns was established. • The working mechanism of HSS-CHCFHSST stub columns under axial compression was revealed. • A theoretical equation for calculating the axial compressive capacity of HSS-CHCFHSST stub columns was proposed. [ABSTRACT FROM AUTHOR]

This paper investigated the axial compressive behavior of concrete-filled square steel tube (CFSST) columns with debonding defects. Experimental tests were conducted on 117 CFSST columns to examine the influence of debonding defects on their failure modes and performance deterioration. The results showed that pronounced buckling and concrete cracking were observed at the debonding interface due to stress concentration. The presence of debonding defects slightly decreases the ultimate load-carrying capacity of CFSST columns but more significantly deteriorates the ductility and initial stiffness. A 2.5 % volume debonding rate reduces ultimate load-carrying capacity by 11.8 %, while ductility coefficient and initial stiffness by 27.4 % and 38.1 %, respectively. Furthermore, the debonding-induced imbalance in the constraint effect of the steel tube significantly contributes to the performance deterioration of CFSST columns. This deterioration is more severe in columns with concentrated defects compared to those with uniformly dispersed defects. Finally, a theoretical formula was proposed to accurately predict the ultimate load-carrying capacity of CFSST columns with debonding defects. This formula takes into account the deterioration of the constraint effect caused by interfacial debonding. These findings inform failure and deterioration analysis for CFST structures with debonding issues. • The performance deterioration of CFSST columns with debonding defects under axial compression was analyzed. • A two-stage stress-strain constitutive model for debonding concrete was developed. • The FEM can effectively simulate the axial compressive behavior of CFSST columns with debonding defects. • A theoretical formula predicting the ultimate load-carrying capacity of CFSST columns with debonding defects was proposed. [ABSTRACT FROM AUTHOR]

This study investigates the post-fire axial compression behavior of concrete-filled stainless steel tube (CFSST) stub columns, aiming to inform strategies for strengthening and retrofitting fire-damaged CFSST structures. The paper reviews the mechanical properties and fire resistance of CFSST, presenting results from a series of fire and axial compression tests conducted on 69 circular CFSST stub columns. Key parameters included fire exposure conditions, stainless steel tube wall thickness, concrete strength, and cooling methods. The analysis includes the failure mode, load-deformation relationship, ultimate bearing capacity, initial compressive stiffness, and ductility of specimens post-fire. The primary post-fire axial compression failure mode of the specimens was characterized by localized buckling uniformly distributed along the vertical axis. For fire durations of 60 min or less, the ultimate bearing capacity of the specimens was largely restored after cooling, with a bearing capacity loss of less than 10 %. Specimens subjected to water cooling exhibited lower initial compressive stiffness and ultimate bearing capacity compared to those cooled by air. Lastly, a formula is proposed for predicting the ultimate bearing capacity of CFSST stub columns following exposure to ISO 834 standard fire conditions. • ISO 834 standard fire tests were conducted in the range of 30 min to 90 min. • The ultimate bearing capacity of CFSST was largely restored after cooling. • Specimens subjected to water cooling exhibited lower initial compressive stiffness compared to those cooled by air. • A formula is proposed for predicting the ultimate bearing capacity of CFSST stub columns following exposure to fire. [ABSTRACT FROM AUTHOR]

Concrete-encased concrete-filled steel tubular (CFST) hybrid structures consist of encased CFST components and reinforced concrete (RC) encasement, posing unique challenges related to their hybrid mechanisms and coupling effects. This study addresses these issues by proposing an automatic and efficient Finite Element (FE) modeling method, which accounts for multiple constitutive models of confined concrete, meticulous grid division and reasonable interaction. The FE modeling method was packaged with a user-friendly graphical interface in the software 'Auto CECFST', which has been shared on GitHub(https://github.com/CECFST/Auto-CECFST.git). The modeling method has been verified by test results on the strength, stiffness and deformation capacity. Utilizing the refined FE modeling method, 7776 FE models are generated based on an orthogonal combination of 7 critical parameters of concrete-encased CFST hybrid structures. To accurately define failure modes, stress ratio (φ) was proposed to achieve quantitative analysis on the failure mode, followed by a comprehensive investigation into the full-range analysis of the hybrid mechanism of two components. Moreover, further exploration focused on multi-parameter coupling effects of critical mechanism characteristics, including strength, stiffness, and deformation capacity, elucidating the hybrid mechanism and mechanical similarities between single and multi-chord structures. Based on the above analysis, the balance of strength and deformation ability could be achieved by certain parameter ranges. Finally, available strength and stiffness calculation methods are validated against experimental and FE results under three typical failure modes, revealing the advantages and limitations of calculation methods on the basis of mechanics and data statistics, which provides a basis for security structural design. • An automated modeling method was proposed and verified for concrete-encased CFST hybrid structures. • 7776 FE models were established to investigate the coupling relationship between 7 parameters and mechanical behaviour. • Revealing the advantages and limitations of calculation methods on the basis of the cooperative working mechanism. [ABSTRACT FROM AUTHOR]

The current AISC Specification lacks clear guidance on the design of circular concrete-filled tube (CCFT) members, while updates to material strength restrictions and the P-M interaction design curve apply exclusively to rectangular shapes. This research is a response to the growing call within the engineering community to update the AISC 360–22 design guidelines for CCFTs. A deterministic and probabilistic approach is presented for assessing the applicability of unifying current AISC 360–22 P-M interaction design equations for use in circular-filled tubes. This assessment is informed by the most up-to-date experimental test results comprising 508 eccentric axially loaded CCFTs with different material strength combinations. Reliability analysis using Monti Carlo simulation demonstrates that the authors' proposed P-M interaction design equations in Appendix II of the AISC 360–22, along with the proposed equation for column, and beam maintain a consistent level of accuracy across different material strengths of circular shapes. An increased safety factor of ϕ c = 0.85 for columns and ϕ b = 0.9 for beams is recommended for a more economical design, aligning with AISC 360–22's requirement for achieving a minimum reliability index of 2.6 under commonly used load combinations. The research findings present a compelling proposal for inclusion in design codes, offering practical tools for engineers to enhance structural design and safety optimization. • Deterministic and probabilistic approach for assessment of the AISC 360–22 P-M interaction design equations • The study suggests extending AISC 360–22 (Appendix II) interaction design to include all normal and high-strength CCFTs • The study proposes a relaxed factor of safety of 0.85 columns and 0.9 for beams of CCFT [ABSTRACT FROM AUTHOR]

• Axial compression tests on CFSTs strengthened with TR-ECC. • Confining stresses provided by TR-ECC and steel tube. • Influences of the number of textile layer, textile grid size, material strength and steel ratio. • Simplified equations for calculating the ultimate strength of CFSTs reinforced with TR-ECC. The combination of engineered cementitious composite (ECC) and fiber-reinforced polymer (FRP) textile systems has proven effective in improving the mechanical performance of structural members. This study focused on the compressive behaviours of concrete filled steel tube (CFST) columns reinforced with carbon fiber textile and ECC. A total of 22 columns were tested under axial compression, considering key parameters such as steel tube thickness, concrete grade, textile grid layer and textile grid size. The failure modes, load-axial deformation curves, and strain development were obtained. The test results indicated that using TR-ECC could effectively improve the ultimate strength of CFSTs, while increasing the grid size from 10 mm to 20 mm had a negligible impact on the ultimate strength. In addition, the stress state of the steel tube and the confining stresses provided by the steel tube and TR-ECC were analyzed based on circumferential and vertical strains. Furthermore, finite element models were established and validated by comparing them with experimental test results. Upon validation, a parametric investigation was conducted to examine the influence of the number of textile layer, textile grid size, material strength and steel ratio on the axial compression behaviours of the composite columns. Finally, simplified equations were developed to predict the axial bearing capacity of CFSTs reinforced with TR-ECC. [ABSTRACT FROM AUTHOR]

• A novel strengthening technique incorporating thin-walled octagonal steel tube and ECC sandwiched layer is proposed. • A total of 29 strengthened concrete stub columns were prepared and tested under uniaxial compressive. • Parameters of steel grade, sandwiched layer material, sandwiched layer thickness, tube aspect ratio, and ECC-concrete interface roughness were investigated. • The proposed strengthening technique can significantly enhance the load-bearing capacity of the rectangular concrete columns with excellent efficiency. Traditional strengthening techniques like concrete jacketing and steel jacketing may no longer suffice to meet the demands of high-performance, efficiency, and low carbon footprint. This paper presents an experimental investigation on a novel strengthening method for reinforced concrete (RC) columns, using external thin-walled octagonal high strength steel tube and sandwiched ECC layers. The impacts of steel grade, sandwiched layer material, sandwiched layer thickness, tube aspect ratio, and ECC-concrete interface roughness on the failure mode, load-bearing capacity, and strain responses of the strengthened concrete columns were explored. Uniaxial compression tests results illustrated the effectiveness of the proposed strengthening technique in utilizing the compressive strength of the steel tube and the advantages of confinement. This method resulted in a notable enhancement in load-bearing capacity, ranging from 304 % to 814 %, with a modest increase in section size of 51 % to 140 %. Furthermore, a significant improvement of up to 24 % in strength was observed when comparing the strengthened column to its nominal strength. Design recommendations were provided based on the design approaches from GB 50936–2014, EN 1994-1-1:2004 and ANSI/AISC 360-22 for CFSTs. The results showed that the design approaches for circular CFSTs in EN 1994-1-1:2004 combined with the confinement coefficient for octagonal section could reasonably capture the compressive capacity of the strengthened columns. [ABSTRACT FROM AUTHOR]

• 14 SS-UHPC columns were test under monotonic or cyclic axial loading. • The failure mode and performance indexes SS-UHPC columns were analyzed. • The confinement effect of SS-UHPC columns were discussed and analyzed. • A novel design formula was proposed to predict the axial capacity of SS-UHPC columns. A novel type of composite column consisting of an ultra-high performance concrete core confined by a stainless steel tube (SS + UHPC column) was investigated. The system is characterized by excellent corrosion resistance, aesthetic appearance, high axial capacity and pronounced ductility. An experimental programme comprising 14 SS + UHPC stub columns was carried out, covering both monotonic and cyclic loading. The main parameters varied in the experiments were the column diameter, the tube thickness and the loading scheme (monotonic or cyclic). The resulting load-displacement curves, failure modes, strain characteristics, axial capacities, confining pressures, stiffness degradation and ductility indices were thoroughly analyzed. The applicability of current empirical formulae in predicting the confined strength of UHPC in SS + UHPC columns was also examined, and found to be inadequate. Therefore, a new equation linking the confining pressure to the confined strength of UHPC was developed. Based on this, a design equation to quantify the axial capacity of SS + UHPC columns was presented. [ABSTRACT FROM AUTHOR]

• Fire tests of circular CFSDT beam-columns under eccentric loading are reported. • A FE model is developed using ABAQUS to simulate structural fire behavior. • A design model is proposed for computing strength envelopes of CFSDT columns. • FE and design models predicts well fire resistance and strength of CFDST columns. Circular concrete-filled double steel tubular (CFDST) beam-columns have increasingly been used in tall composite structures and must be designed for fire safety. However, there is a lack of appropriate design methods for the fire safety design of such composite beam-columns because research work on their fire performance has been very limited. This paper studies the behavior and design of circular CFDST beam-columns under eccentric loading and fire exposure. The standard fire tests and results are reported on CFDST beam-columns subjected to eccentric loads. A numerical model developed using ABAQUS is described for simulating the fire performance of CFDST beam-columns, which accounts for the concrete transient creep using the user-subroutine UEXPAN. The finite element simulation technique is employed to study the fire behavior of circular CFDST beam-columns having various parameters. A method is proposed for calculating the strength of CFDST beam-columns in a fire condition. The results demonstrate that increasing the column slenderness, eccentricity ratio, and axial load ratio significantly reduces the fire resistance time and capacity of CFDST beam-columns. Increasing the material strength considerably improves the fire resistance of filled composite columns. The developed finite element simulation model predicts well the behavior of CFDST beam-columns exposed to fire. The proposed method can yield satisfactory strength calculations of CFDST beam-columns, suggesting that it can be utilized in practical design of such composite beam-columns for fire safety. [ABSTRACT FROM AUTHOR]

• Experimental studies were carried out on UHPC columns reinforced with different configurations of HSS reinforcements and tubes. • The load-deformation hysteretic curves and the strain of the specimens were obtained. • The effect of various configuration of HSS reinforcements and tubes on the performance of specimens was assessed. • Cost-effective assessments of specimens were investigated. This paper investigates the behavior of circular hollow ultra-high-performance concrete (UHPC) columns reinforced with high-strength steel (HSS) tubes or reinforcements under combined loads, addressing a significant research gap in the application of UHPC for wind turbine towers. Previous studies have primarily focused on conventional towers, lacking comprehensive comparisons of the performance of UHPC columns with various HSS confinement forms such as hollow reinforced concrete (HRC), concrete-filled double-skin steel tubular (CFDST), internally confined hollow reinforced concrete (ICHRC), and externally confined hollow reinforced concrete (ECHRC). To bridge this gap, an experimental study was conducted on four different confinement forms of hollow circular UHPC columns: CFDST, ECHRC, ICHRC, and HRC. These columns were subjected to combined loads of constant compression and cyclic bending. The performance of five specimens was assessed by comparing failure modes, hysteresis curves, ultimate capacity, stiffness degradation, ductility, and energy dissipation, identifying cost-effective confinement forms. The study revealed that UHPC HSS composite columns exhibit characteristic bending damage modes, with external steel tubes significantly enhancing their ultimate capacity and energy absorption. Replacing the internal HSS tube with reinforcements increased the load-bearing capacity by up to 5.6 %. Substituting external steel tubes with steel bars leads to an 18 %-27 % reduction in load-bearing capacity. In terms of ductility, CFDST columns showed notable improvements, with a 2.8 % increase over ECHRC column and a 7.53 % increase over ICHRC column. The ECHRC column was identified as the most cost-effective, while CFDST columns, although high-performing, incurred higher costs. Finite element simulations of specimens were developed and validated the experimental results, with errors under 10 %. Finally, the feasibility of predicting the ultimate strength of the columns using existing methods was evaluated based on the experimental data. [ABSTRACT FROM AUTHOR]

[Display omitted] • Oil-CO 2 -water three-phase fluids behavior under the nanopore confinement effect were analyzed. • Mechanisms of CO 2 -EOR and carbon storage in hydrated shale nanopores were revealed. • Effects of water, mineral, temperature and pressure on CO 2 -EOR and carbon storage performances in nanopores were discussed. The widespread nanopores, diverse minerals, and varying water saturation in shale reservoirs complicate the mechanism analysis and performance prediction of CO 2 enhanced oil recovery (CO 2 -EOR) and CO 2 storage (CS) in hydrated nanopores. Therefore, molecular dynamics methods were used to simulate the process of CO 2 replacing shale oil in hydrated nanopores of inorganic, organic and composite minerals. Importantly, the effects of mineral type, temperature, pressure and water content on CO 2 -EOR and CS performances in hydrated nanopores were analyzed, and the CO 2 -EOR mechanisms of dissolution, extraction, viscosity reduction, miscibility and competitive adsorption were revealed. The results show that water in illite, kerogen, and composite nanopores are distributed in the forms of water films, water clusters (films), and water columns, respectively. The replacement efficiency of shale oil in three types of nanopores is improved with increased water content but reduced in kerogen nanopores under high water content. Water is not conducive to the diffusion and viscosity reduction of oil in nanopores, but the miscibility and competitive adsorption of CO 2 and oil are improved. The replacement efficiency is positively correlated with temperature and pressure. The increasing temperature promotes diffusion and viscosity reduction of oil and competitive adsorption between CO 2 and oil in hydrated nanopores, and increasing pressure promotes miscibility and competitive adsorption. Water columns in kerogen and composite nanopores reduce the CS performance, while thin water films in illite nanopores improve it. Moreover, an excellent CS rate can be achieved at high temperatures and pressures, but the high temperature is not conducive to CS stability. This study provides a theoretical basis for CO 2 injection to improve oil production and carbon storage performance in hydrated shale reservoirs and contributes to the optimization of CO 2 injection schemes. [ABSTRACT FROM AUTHOR]

Rectangular concrete-filled steel tubes (RCFSTs) are widely utilized structural solutions due to their exceptional mechanical behavior under combined compression and bending, characterized by the load–moment (N – M) interaction curve. However, with the advancement of high-performance materials, existing codes are inapplicable, and the scarcity of pure bending experimental data constrains the development of general calculation formulae. In this study, a composite multi-fidelity neural network (CMFNN) is proposed to predict the parabolic N – M curve by incorporating a high-fidelity network and an empirical bending strength method. A total of 1005 axial compression tests and 401 eccentric compression tests collected from a comprehensive literature review are employed to train the proposed model. Compared with specifications and a back propagation neural network, the high-fidelity network, which predicts axial strength through the sequential acquisition of concrete and steel coefficients, demonstrates superior accuracy, with a mean absolute percentage error (MAPE) of 6.04%. To capture the curve's transition with slenderness, the eccentric compression data is subdivided into three subsets. This approach significantly improves prediction performance, especially in high-slenderness tests. Each subset exhibits a coefficient of determination (R2) above 95% and a MAPE below 8.72%, outperforming traditional methods. The analysis of the feature importance conducted by the SHapley Additive exPlanations (SHAP) algorithm indicates that the primary factors affecting the curve shape shift from the strength and thickness of steel tube to concrete strength and specimen length as slenderness increases. Additionally, sensitivity analysis demonstrates that height feature predominantly impacts eccentric strength, providing effective guidance for practical engineering applications. [ABSTRACT FROM AUTHOR]

This study investigates the structural behavior of concentrically and eccentrically-loaded ultra-high-performance concrete-filled double skin steel tube (UHPCFDST) short columns with polygon sections. A total of eight specimens, including two concentrically-loaded specimens and six eccentrically-loaded specimens, were prepared and tested. The effects of loading eccentricity (0, 50, 75, and 100 mm) and outer steel tube shape (hexagonal and octagonal) on the behavior of UHPCFDST short columns are investigated. Based on the experimental results, it is found that the failure modes of concentrically-loaded UHPCFDST short columns include outward buckling of outer steel tube, oblique shear, corner and weld fractures, crushing of sandwiched concrete, and inward buckling of inner steel tube, while the eccentrically-loaded specimens experienced outward local buckling of outer steel tube, concrete crushing at the compression side, concrete cracking at tension side, and bending of inner steel tubes. It is also observed that increasing the eccentricity reduces the initial stiffness and ultimate strength of the test specimens. In contrast, it increases the bending capacity and ductility of eccentrically-loaded specimens. Besides, it is demonstrated that specimens with octagonal sections provide higher initial stiffness, ultimate strength, and ultimate moment compared to those of hexagonal sections across all the eccentricities. However, the hexagonal specimens exhibit higher ductility than octagonal specimens. The test results are further employed to validate the applicability of codified N-M interaction curves provided in AISC-360, EC4, and GB-50936 standards. It is revealed that AISC-360 significantly underestimates the ultimate strength of polygonal UHPCFDST columns, while EC4 and GB-50936 show reasonable predictions of ultimate strength with a slight discrepancy. • Polygonal UHPCFDST short columns were tested under concentric and eccentric compression. • The effect of different parameters on the performance of polygonal composite columns was investigated. • The structural behavior of concentrically and eccentrically-loaded polygonal UHPCFDST columns were discussed. • The codified N-M interaction curves were validated against experiment results. [ABSTRACT FROM AUTHOR]

This study designs and fabricates nine RPC-filled circular steel tube (RPC-FST) columns to investigate their compression-bending hysteresis performance and seismic behavior. It conducts low-cycle reciprocating tests on the columns to obtain and analyze the load-displacement hysteresis and skeleton curves of the nine RPC-FST columns. This research also examines the effects of the axial compression ratio and the diameter-to-thickness D / t) ratio on the load-displacement skeleton curves and the seismic performance indices such as the ductility coefficient and equivalent viscous damping coefficient of the specimens. The test results revealed that the hysteresis loop of the RPC-FST column is plump and fusiform-shaped without pinching, indicating that the RPC-FST column possesses a favorable energy dissipation capacity. The ultimate drift ratios of the nine specimens range from 3.5 % to 7.9 %, and their ductility coefficients range from 3.2 to 4.6, indicating that the RPC-FST columns have good ductility and deformation capacity. The specimen's ductility coefficient decreased as the axial compression ratio and D / t ratio increased. Finally, the compression-bending capacity of RPC-FST columns is calculated based on the current GB50936–2014, EC4, AIJ, and AISC-LRFD codes. • The low-cycle reciprocating tests were performed on RPC-FST columns. • The hysteresis loop of the RPC-FST columns exhibits a fusiform shape without pinching. • The ultimate drift ratios of specimens are 1.8 to 3.9 times the drift ratio limit of RC frames. [ABSTRACT FROM AUTHOR]

Circular concrete-filled double skin steel tubular (CFDST) columns show great potential in various infrastructures due to their excellent structural performance and easy construction process. As the rapid development of infrastructure towards large scales and manifold functions, CFDST columns within an extended scope of dimensions and sectional configurations will be applied in engineering practice. This trend poses challenges to both the accuracy and efficiency of traditional strength prediction methods including design equations, experimental fitting and numerical simulations. Based on experimental datasets obtained from existing research, machine learning (ML) methods pave a path for understanding the complex relations between key parameters and the axial compressive ultimate strength of CFDST columns. This paper attempts to develop reliable ML-based models for predicting the axial compressive ultimate strength of CFDST columns. Three advanced ML algorithms, namely Back Propagation Neural Network (BPNN), Support Vector Regression (SVR) and Gaussian Process Regression (GPR), were adopted to develop prediction models by training an experimental database of 162 CFDST specimens from existing literature which covers a wide scope of parameters including high diameter-to-thickness ratios and large hollow ratios. Particularly, Particle Swarm Optimization (PSO) method was used to optimize the hyperparameters of ML algorithms for enhancing the prediction accuracy. The performances of the developed prediction models were evaluated through an in-depth comparison analysis. It is found that the ML-based models could predict the strengths of CFDST columns with higher accuracies and wider applicable ranges than existing design methods; PSO-enhanced GPR (PSO-GPR) model achieved the most improved performance for strength prediction. Further validation on PSO-GPR model was conducted based on experimental data from recently tested large-dimension CFDST specimens and the results demonstrate the wide applicability of the developed model. • Three advanced ML-based ultimate strength prediction models of CFDST columns are developed. • PSO method is used to enhance the accuracy of prediction models. • An experimental database covering a wide scope of key parameters is established. • The developed models are evaluated by in-depth comparison analysis and test results. [ABSTRACT FROM AUTHOR]

This paper presents experimental investigation on the post-fire performance of geopolymeric recycled aggregate concrete filled steel tube (GRACFST) columns and temperature field of GRAC cubes. A total of 10 GRACFST column specimens were tested to investigate their post-fire performance. A total of 10 GRACFST column specimens were tested to evaluate their performance after exposure to fire, considering various parameters: (a) cross-section type (circular and square); (b) testing conditions (ambient temperature test, post-fire test without initial load, and full-coupled post-fire test); (c) target temperatures (20 ℃, 600 ℃, and 800 ℃); and high-temperature exposure durations (30 min and 180 min). The study examined failure modes, temperature evolution, deformation and strain patterns, and post-fire ultimate bearing capacities. The test data revealed the commendable post-fire performance of GRACFST columns, as evidenced by the residual strength index typically falling within the range of 0.83 to 1.11. To calibrate the thermal properties of GRAC materials, a series of temperature field tests of GRAC cubes at different target temperatures (200 ℃, 400 ℃, 600 ℃ and 800 ℃) were conducted. These tests provided data on temperature distribution within the cubes and mass loss due to high temperatures. Using back analysis of these temperature field tests, thermal property models for GRAC, including thermal conductivity, specific heat, and density, were developed and validated by simulating temperature data from existing fire and post-fire tests of GRACFST columns. The proposed thermal property models are crucial for designing this novel composite column type for fire resistance applications. • Experimental study on post-fire performance of geopolymeric recycled aggregate concrete filled steel tube (GRACFST) columns. • Temperature field test of geopolymeric recycled aggregate concrete (GRAC) cubes. • Thermal property models of GRAC based on back analysis from temperature field test of GRAC cubes. • A verified finite element analysis (FEA) model to temperature field of GRACFST columns in fire. [ABSTRACT FROM AUTHOR]

• Employment a comprehensive dataset including vital material and environmental factors. • Powerful ML framework enables precise fracture toughness prediction in concrete. • Carbon and steel fiber-reinforced concrete significantly boosted fracture resistance. Fracture toughness (FT) is one of the most important material characteristics that determines the mechanical stability and operational performance of concrete structures, but its accurate measurement is rather difficult due to the complicated, expensive, and lengthy nature of the common experimental approaches. This study proposes a novel approach that combines machine learning (ML) with empirical information from three-point bending tests to estimate FT for a large set of concrete formulations. A dataset of 600 samples, which were carefully prepared and tested, containing aggregates of different sizes, water-cement ratios, curing conditions, and material additives, was used. Compared to other ML algorithms, the AD-XGBoost model achieved the best results by predicting FT with R2 values of 0.99 and NRMSE of 0.0008. As per the sensitivity analyses, cement type, fiber percentage, and curing temperature were the most influential parameters on FT, while the inclusion of carbon and steel fibers into the concrete matrix enhanced its structural stability. Improvement of the toughness of concrete was also noticed with a prolonged curing process. Besides being an effective and reliable substitute for the prediction of the FT, this ML modelling strategy significantly minimizes the need for resource-demanding laboratory tests. [ABSTRACT FROM AUTHOR]

This study investigated the axial compressive performance of square concrete-filled steel tube (CFST) short columns strengthened with high-strength square steel tubes and concrete jackets. 22 columns were tested: 1 reference column, 15 columns strengthened with high-strength steel tubes, and 6 columns strengthened with standard steel tubes. The test results showed significant improvements in the load-bearing capacity, ductility, and stiffness of the CFST columns after strengthening by high-strength steel tubes. For strengthened columns, there was a general upward trend in the improvement of load-bearing capacity when Q460, Q550 and Q690 steel tubes were used for strengthening relative to the use of Q235 steel tubes. However, the specimens strengthened with Q690 steel tubes showed corner cracking during loading resulting in a lower increase in load-bearing capacity of some of their specimens than the specimens strengthened with Q550 steel tubes. Therefore, it is recommended to use high-strength steel tubes with strength grades of Q550 or lower for reinforcement projects. A finite element (FE) model was established and verified using the test results. The FE model showed that utilizing high-strength steel tubes enhanced the synchronization of displacements corresponding to the ultimate load of the original and post-cast concretes and improved the bearing capacity of both. Furthermore, a new formula was proposed to predict the load-bearing capacity of columns strengthened with high-strength steel tubes and concrete jackets. The results of this formula showed strong agreement with those of the experiment and FE model. • CFST columns were strengthened with high-strength steel tubes and concrete jackets. • Effect of high-strength steel on mechanical behavior of columns was evaluated. • A calculation model was proposed to predict the axial load bearing capacity. [ABSTRACT FROM AUTHOR]

The geosynthetic-encased stone column (GESC) is a cost-effective and efficient soil treatment method widely adopted in seismic regions. Its pivotal role in fortifying foundations enhances the safety of the supported structures. This study focuses on the fragility analysis of GESC composite foundations under seismic loads. The application of Logistic regression, a machine learning technique, derives parameterized fragility functions. These parameterized fragility functions elucidate the effects of GESC diameter, encasement tensile strength, column friction angle and soil variability on the GESC composite foundation's failure probability. The results demonstrated the efficiency of Logistic regression in predicting GESC foundation failure probability, boasting an impressive determination coefficient of up to 99.8 when compared with the Monte Carlo Simulations (MCS). Enhancing the tensile strength of the encasement and the column's friction angle reduces the failure probability in GESC foundations. Also, increasing the replacement ratio reduces the failure probability of the GESC foundation. However, for a constant replacement ratio and the same geosynthetic encasement, the seismic bearing capacity of a composite foundation reinforced by GESCs with small diameter is superior to that reinforced by GESCs with large diameter. Notably, inherent soil variability escalates the failure probability of GESC foundations, emphasizing the importance of selecting high-performance GESCs, especially when treating soil with strength that is characterized with a higher coefficient of variation (COV). • A simplified approach proposed to compute the seismic bearing capacity of GESC foundations. • A machine learning technique used to predict GESC foundation failure probability. • Determination coefficient of up to 99.8 compared with the Monte Carlo Simulation. • Design suggestion of GESC considering the inherent soil variability. [ABSTRACT FROM AUTHOR]

Shear connectors are essential components for force transfer in composite beams. Compared to conventional welded-bolt connectors, bolted shear connectors offer the advantage of easy removal. However, traditional bolted connectors for steel-concrete composite beams feature threads on the contact surface, reducing the shear cross-sectional area of the bolts. To address this limitation, this paper proposes a novel type of friction-clamping bolt connector, referred to as Connecting Lock Combination Bolts (CLCB 1 1 CLCB:Connecting Lock Combination Bolts；). The finite element software ABAQUS was used to develop an analytical model for the CLCB, and a comparative analysis was conducted with traditional connectors. The static performance of the new shear connectors was evaluated, and a shear load capacity formula applicable to CLCB connectors was derived. Additionally, linear and exponential functions were employed to fit the load-slip curve of the CLCB connectors. The results indicate that the shear load capacity of CLCB connectors exceeds that of conventional bolted connectors. Moreover, the bolt diameter and concrete strength are the primary factors influencing the ultimate shear load capacity and stiffness of CLCB connectors. The preload on the bolts enhances the shear stiffness, while parameters such as bolt hole clearance, the height of the lower nutted rod, and the clearance between the upper and lower bolt rods are crucial in ensuring the proper functioning of CLCB connectors. Furthermore, the shear capacity formula provides an accurate prediction of CLCB connector performance with an error margin of less than 6 %, and the load-slip curve model effectively illustrates the load-slip relationship under shear. • A novel locking bolt connector exhibiting high ultimate shear capacity. • Finite element analysis confirms factors influencing the shear strength of CLCB. • New connector outperforms traditional bolts in capacity and material use. • Shear capacity formula for CLCB derived using linear and exponential models. [ABSTRACT FROM AUTHOR]

Combining the characteristics of concrete-filled double-skin steel tube (CFDST), this paper devised a joint construction form featuring low-beam with haunch partially penetrating into the inner layer of steel tube, thus proposing the joint between unequal-depth steel beam with haunch and CFDST column. This paper conducted finite element analysis of this novel joint under low-cycle reversed loading using ABAQUS software. By taking beam height ratio, axial compression ratio, beam-column width ratio, beam flange width-thickness ratio, and beam web height-width ratios as analysis parameters, the seismic performance of the joint was systematically studied. The results indicated that beam height ratio, axial compression ratio, beam-column width ratio, and beam flange width-thickness ratio have a significant impact on the seismic performance of the joint, while the beam web height -width ratios has a minor effect. Furthermore, through the analysis of the force mechanism and internal force derivation of the core area of the joint between unequal-depth steel beam with haunch and CFDST column, a shear bearing capacity calculation method applicable to such connections was established. This calculation method aligns well with the numerical analysis results and can accurately assess the shear bearing capacity of the core area of this type of joints. • A joint construction form with a low-beam and haunch partially penetrating the inner layer of the steel tube was devised. • The seismic performance of the joint was studied by considering different parameters such as the beam height ratio. • A shear bearing capacity calculation method for such connections was established by analyzing mechanism of the joint. [ABSTRACT FROM AUTHOR]

This study investigates the mixed-mode fracture behavior of self-compacting concrete specimens reinforced with longitudinal steel bars and steel fibers. The experimental program involved three-point bending tests on asymmetrically notched prismatic specimens designed to induce and propagate mixed-mode cracks. The influence of different steel fiber dosages on crack initiation, propagation, and final failure was evaluated. Key findings reveal that the addition of steel fibers significantly enhances energy absorption and ductility under combined mode I and mode II fracture conditions. The results demonstrate the effectiveness of steel fibers in delaying brittle failure and improving the overall structural performance. Novelty lies in the combined use of self-compacting concrete and steel fibers to explore mixed-mode fracture mechanisms in reinforced elements. • Mixed-mode fracture behavior of self-compacting concrete under quasi-static load conditions. • Steel fiber reinforcement significantly enhances ductility and energy absorption. • Experimental study reveals the impact of fiber content on crack propagation patterns. • Innovative methods combine longitudinal steel bars and fibers for improved strength. • Results highlight critical role of steel fibers in mixed-mode fracture resistance. [ABSTRACT FROM AUTHOR]

This study tackles the multi-objective optimization (MOP) challenges in constructing steel–concrete columns by introducing a novel TCQE model that considers time, cost, quality, and carbon emissions. Employing relative deviation theory with dynamic weighting, the model normalizes MOP and applies an improved ant colony algorithm (IACA) to generate optimized solutions. Empirical research validates the model's efficiency and applicability. Furthermore, a decision-making framework based on AHP-TOPSIS is proposed, demonstrating superior weight distribution and fairness in the decision process. Compared to the ideal point method and VIKOR, the proposed approach consistently identifies optimal solutions, affirming its scientific validity and effectiveness. The findings suggest broad application prospects in practical construction projects and provide valuable insights for construction management research, highlighting the theoretical and practical significance of the model and framework. [ABSTRACT FROM AUTHOR]

To further reduce the demand for natural aggregates in concrete production, this study introduces a new compound concrete RLSSC—recycled lump/seawater sea-sand concrete. Additionally, an innovative semi-precast composite column—RLSSC filled precast GFRP tube segments (PSs) confined by grouted steel tubes—is proposed to effectively mitigate the adverse effects of chloride ions and demolished concrete lumps (DCLs) in RLSSC, while also accelerating on-site construction efficiency and expanding the scope of applications. A total of 30 single PS columns and 17 composite columns were tested under axial load, with key test parameters including the mix ratio of DCLs to SSC (r), the number of PSs in the composite columns, and the slenderness ratio. The results indicate that, in single PS columns, the adverse effects of DCLs, particularly when the r is 35 %, cannot be effectively mitigated by FRP confinement. In contrast, the grouted steel tubes used in composite columns can effectively mitigate the negative impact of DCLs and enhance the ductility of the columns. Furthermore, the use of multiple PSs effectively improves on-site construction efficiency without adversely affecting the axial performance of the columns. Finally, a formula for predicting the stable load capacity of composite columns is proposed, providing valuable reference for practical engineering applications. • A new compound concrete–recycled lump/seawater sea-sand concrete was introduced. • An innovative semi-precast composite column was proposed. • 17 composite columns and 30 single PS columns and were tested under axial load. • The adverse effects of DCLs and SSC were restrained in proposed column. • A stability load capacity formula for composite columns has been proposed. [ABSTRACT FROM AUTHOR]

This paper presents an experimental investigation on the joints between four-limb concrete-filled steel tubular (CFST) latticed column and composite box girder under low-cycle reciprocating loading. The load-displacement hysteresis curve and skeleton curve of the joint were obtained, as well as the failure mode of the joint. Based on the joint test, a finite element (FE) model was established and validated with the experimental results. The validated FE model was used to obtain the load-displacement skeleton curves for the 140 joint specimens under different parameter combinations, which facilitated the development of a machine learning based predictive model to evaluate the effects of various parameters on the seismic performance of the joints. Six parameters on the skeleton curve of the joint was studied by mRMR, which are the concrete strength, yield strength of transverse diaphragm plate, steel bar diameter, axial compression ratio, concrete slab thickness, and yield strength of steel box girder. Five machine learning (ML) algorithms were used to predict the joint's skeleton curve considering the six parameters. The skeleton curve, positive and reverse stiffness and ultimate load obtained from the predictive models and test results were compared. The results show that the numerical results match well with the experimental results, and thus the FE model can be used to develop a database. Among the six parameters, the axial compression ratio has the greatest influence on the skeleton curve, while the steel bar diameter has the least impact. Among the five machine learning (ML) algorithms, the XGBoost algorithm consistently achieved the lowest errors across three metrics, demonstrating a better performance in prediction. With a prediction accuracy approaching 98 %, it is shown to be suitable for predicting the skeleton curves. • An experimental study was performed to investigate the seismic behavior of joints. • A validated FE model generated 140 skeleton curves dataset, aiding ML predictions. • mRMR algorithm is used for parameter sensitivity analysis, guiding joint optimization. • Five algorithms predicted skeleton curves, with XGBoost showing the highest accuracy. • XGBoost algorithm predicted skeleton curves, providing dataset for joint optimization. [ABSTRACT FROM AUTHOR]

The automotive industry is progressively focusing on lightweight, eco-friendly, and crashworthy composite structures to enhance vehicle performance, safety, and reduce the carbon footprint. Natural fibres are crucial for advancing green composites, although their mechanical performance lags behind synthetic counterparts, like carbon, posing challenges for their exclusive use in structural components. In this context, hybridization is a promising strategy, balancing environmental benefits and mechanical efficiency. This study focuses on the crashworthiness performance of flax/epoxy, carbon/epoxy, and hybrid flax-carbon/epoxy circular tubes with three different triggers, under quasi-static axial crushing. After the mechanical characterization of composite materials, a finite element model of such structures is developed to reproduce their crushing phenomenon through LS-DYNA software. Numerical simulations show favorable agreement with experimental outcomes, validating the effectiveness of the designed models. Overall, test results underscore the potential of hybrid materials for crashworthy components, providing a promising alternative to purely carbon fibre-based structures. [ABSTRACT FROM AUTHOR]

This article presents the application of stress field models for strength prediction of discontinuity regions in steel-reinforced glass structures failing due to crushing of the glass and failure of stainless steel reinforcement. One of the main assumptions in the proposed modelling approach is that the structural laminated glass has similar compressive features as high-strength concrete within a framework of the stress field method. The paper initially introduces theoretical and experimental aspects and similarities between compressive behaviour of glass and high-strength concrete. Considerations on the compressive strength of laminated glass as well as the softening effect of cracks through the transverse strain factor are presented. The softening effect of cracks is investigated using the results of bending tests on beams and detailed digital image correlation (DIC) measurements. Finally, the proposed models are compared with results of tests on steel-reinforced glass members encompassing local compressive tests, bending tests and tests on beam-column connections. Additionally, the three groups of tests are numerically simulated using elastic-plastic stress fields (EPSF), through the finite element (FE) software EvalS for the automatic development of 2D stress fields. This numerical tool was originally developed for design and assessment of RC discontinuity regions. It is found that the numerical predictions are in a good agreement with test results. It is concluded that the stress fields may serve as a tool for the verification of a post-fracture limit state. • Structural laminated glass enhances safety by reducing risks from sharp shards. • Steel-reinforced glass components enhance load-bearing and post-fracture capacity. • Compressive and shear tests are performed to evaluate the compressive and shear strength. • Stress concentrations in discontinuity regions in steel-reinforced glass are studied with stress fields. • Elastic-plastic stress fields and corresponding strut-and tie models are applied to study discontinuity regions. [ABSTRACT FROM AUTHOR]

This paper presents and discusses the structural behaviour of a novel type of steel–timber composite column to be used in residential building applications. It consists of a circular hollow section wrapped by multiple beech veneer sheets and where the composite action is ensured by a structural bi-component glue applied over the contact surfaces. As part of a proof-of-concept study, five short and three long columns with lengths of 0.27 m and 2.00 m, respectively, were tested under vertical concentric load with fibres parallel to the load direction and inclined by 15°. The global response of the specimens in terms of load-displacement behaviour and failure modes was studied, along with localised strain measurements through strain gauges and a digital image correlation (DIC) system. Results showed a significant increase in buckling resistance due to the stiffness added by the veneer layers. Already with the still-moderate veneer layer thicknesses used in this study, an increase in strength of over 25 % could thus be achieved. This enhancement highlights the effectiveness of veneer wrapping in stabilizing the inner core and delaying the occurrence of flexural buckling failure. A 3D non-linear finite element model (FEM) validated these findings, showing a good correlation with experimental results in resistance and stiffness. A parametric study was conducted to explore different geometries and materials, thus creating an extended FEM-based database. A relatively good agreement with modest deviation between the FEM predictions and analytical formulations available in the European Standards was found, considering the appropriate introduction of the mechanical properties of timber. • Tests on concentrically-loaded veneer-wrapped steel columns show that the outer veneer layers enhance the buckling strength. • Compared to bare steel columns, composite veneer-wrapped columns exhibit higher resistance (up to 25 %) and stiffness. • A 3D non-linear finite element model (FEM) was developed and validated to extend the findings of the experimental results. • A parametric study was conducted to assess the performance of the performance of different configurations and support design guidelines. [ABSTRACT FROM AUTHOR]