Tensile Resistance Research Articles

Materials Behaviour Analysis of 3D Printed Brass-PLA Filament

The current study aims to bridge a crucial gap in existing research, potentially paving the way for a groundbreaking transformation in the development and application of PLA/Brass composites within diverse industries such as aerospace, automotive, consumer goods, and medical devices. The primary objective of this research is to assess the mechanical properties of a composite material made up of Polylactic Acid (PLA) and Brass, produced using Fused Deposition Modelling (FDM) 3D printing technology. Brass, renowned for its exceptional mechanical properties, has been integrated into PLA to form this composite material. The study employs various analytical techniques, including Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy-Dispersive X-ray Spectroscopy (EDX), to scrutinize the chemical and physical characteristics of the PLA/Brass composite. This research revolves around exploring the impact of different printing parameters on the mechanical behavior of the printed specimens. The investigation delves into aspects such as tensile strength, compression resistance, bending properties, and impact resistance. To achieve this, test specimens with varying compositions have been produced using a Raise3D N2 Plus FDM 3D printer, with careful manipulation of printing parameters such as layer height and printing speed. The compositional variations range from 15% wt. to 80% wt., with layer height values spanning 0.25 mm, 0.30 mm, and 0.35 mm, and printing speeds ranging from 20 mm/s to 40 mm/s. The outcomes of this research have revealed the distinct influences of specific printing parameters on various mechanical properties. For example, in the context of tensile testing, it was observed that the combination of a layer height of 0.25 mm and a printing speed of 30 mm/s resulted in the highest elastic modulus. Similarly, the study provides crucial insights into optimizing PLA/Brass composite material properties through controlled additive manufacturing parameters, catering to diverse application requirements. Key findings include an elastic modulus of 0.870 GPa, ultimate tensile strength of 17.53 MPa, yield strength (0.2% offset) of 15.47 MPa, bending strength of 42.25 MPa, bending modulus of 3.679 GPa, compression strength of 33.46 MPa, compression modulus of 5.748 GPa, and energy absorption of 0.246 J. This study advances our knowledge of PLA/brass composite while also providing a chance to create innovative materials.

Impact of treatment temperature of metakaolin on strength and sulfate resistance of concrete

Calcined clay, a widely studied supplementary cementitious material, has shown positive impacts on concrete's microstructural properties, strength development, and durability. The variation in raw clay mineral concentration across different locations influences the optimal calcination temperature needed to activate its pozzolanic reactivity. This investigation focuses on studying the effects of calcination temperature on the characterization and pozzolanic reactivity of Nigerian Kaolinite clay. The clay was calcined at temperatures ranging from 600˚C to 900˚C for 2 hours. Characterization involved X-ray Diffraction (XRD), X-ray Fluorescence (XRF), and Scanning Electron Microscope (SEM) analyses. Blended mixtures, incorporating 10%, 20%, 30%, and 40% metakaolin as cement replacement, were assessed for workability, strength, and durability properties at 7, 14, 28, and 56 days to determine the clay's pozzolanic reactivity. XRF categorized the metakaolin as a class N pozzolan, while XRD indicated that 800˚C for 2 hours was necessary for complete dihydroxylation. Compressive, tensile, and sulfate resistance tests confirmed that treating the clay at 800˚C for 2 hours optimized its performance. The mix with 10% metakaolin outperformed the control by 6.4%, 14.7%, and 14.1% in compressive strength at 14th, 28th, and 56th days, respectively. While the best performance was at 10% replacement, levels up to 30% also demonstrated satisfactory results compared to the control, showing potential for achieving desired strengths. Linear regression models were also developed to establish the relationship between compressive and split tensile strengths across curing periods. The resulting equations demonstrate excellent predictive performance with correlation coefficients ranging from 0.928 to 0.991.

Comparative evaluation conducted on the selection of the type of roller shredder for the cultivation of plowed land

The results of experimental investigations into the features of the roller shredder that breaks down plowed land one by one are presented in this article. This allowed for the determination of the optimum roller parameter values and the examination of the shredder type selection. According to experimental research, selecting the right type of roller is primarily responsible for guaranteeing that the field surface is completely treated. Typically, these rollers are working parts with slats, gear-slats, or rods for installation on a reel that provide moisture feeding at the level necessary for germination in compliance with agrotechnical requirements. Slatted, toothed-slatted, and rod roller shredders with comparable diameters were designed and used in experimental investigations to confirm the results that we had acquired. In experimental studies, after using different constant diameter roller shredder, the influence of soil on the degree of abrasion, its density and drag resistance was studied. To reduce the influence of various variable factors on the results obtained, the experiments were carried out on a specially prepared agricultural background, which was first plowed and then leveled. In order to test the theoretically based parameters of the roller shredder selected for experimental research in the field, a fixed-diameter roller shredder base with a coverage width of 1.5 m and strips with gear strips and rod strips that can be installed on them were developed and prepared. Based on the results of experimental studies, the following can be noted: in order for the quality and density of soil abrasion to meet agrotechnical requirements, and the tensile resistance of the coil to be minimal, the roller shredder must be with a slatt.

A single carbon nanotube-entangled high-performance buckypaper with tunable fracture mode.

It is well known that the traditional buckypaper (BP) is composed of a certain number of short carbon nanotubes (CNTs) intertwined with each other and sliding always happens when the BP is under tensile and impact loading, which results in inferior mechanical properties compared to single CNTs. In this work, a highly-entangled single-wire BP (SWBP) structure is constructed by a modified self-avoiding random walk approach. The in-plane mechanical properties and impacting behaviors of the SWBPs with different entanglement degrees and interface frictions are systematically investigated via newly developed coarse-grained molecular dynamics (CGMD) simulation. A coarse-grained method can effectively reflect the inter-tube van der Waals (vdW) interactions and the mechanical behaviors of CNTs, including tension, bending and adhesion. In this work, from the tensile simulations of the SWBP, the results showed that the self-locking mechanism between entangled CNTs could significantly enhance the tensile resistance of the film. Besides, the mechanical properties of the SWBP are highly dependent on the entanglement degree and the interface friction between CNTs. Furthermore, two distinct fracture modes, ductile fracture and brittle fracture, are revealed, which can be efficiently controlled by changing the related friction between CNTs. From the impacting simulations, it is found that the impacting performance can be effectively tuned by adjusting the entanglement degree of the film. In addition, the kinetic energy of the projectile could be rapidly dissipated through the stretching and bending of CNTs in the SWBP. This work provides an in-depth understanding of the effect of interface friction and entanglement degree on the mechanical properties of the buckypaper and provides a reference for the preparation of strong CNT-based micromaterials.

Parameters of a combined plow rotor for the climatic conditions of the Bukhara region

In this article, pretreatment of the soil in Bukhara includes simultaneous softening, compaction and crushing of plant residues. As a result, the movement of agricultural machinery in the field is reduced, and the compaction of the subsurface layer is reduced by 5-7 times. For this purpose, the installation and grounding of an additional rotary mill assembly to the fork body is described. Pre-sowing processing consists in the justification of constructive and technological parameters and modes of operation of the crop-milling aggregate, which improve the quality and reduce the tensile resistance. Theoretical studies were carried out using the laws of mathematical analysis and theoretical mechanics. Multi-factor experiment planning methods have been used to conduct experimental research. The results of the study were processed using the methods of Mathematical Statistics.

Effect of Adding Carrageenan Processing Solid Waste from Eucheuma cottonii to Art Paper Manufacture from Water Hyacinth

The carrageenan industry produces solid waste E. cottonii of 65% to 70%, so it had the potential to be used as a paper material. The aimed of this study was to analyze the effect of the concentration of E. cottonii waste which was added in the production of art paper from water hyacinth stems on the quality of the paper. The experimental design used was Complete Randomized Design with 1 factor, namely the difference of Eucheuma cottonii waste concentration (0%, 10%, 15%, and 20% (w/w)). The results showed that the addition of carrageenan processing from E. cottonii with difference concentration gave significantly different (p<0.05) on the value of grammage, tensile strength, tear resistance, density, and lightness of the paper. The best concentration of Eucheuma cottonii was 15% because it had the highest tear resistance value (p<0.05) and higher of lightness than the concentration of 0% and 10% (p<0.05). Paper with waste E. cottonii 15% had a grammage 148.93 g/m2; tensile resistance 1.28 kN/m; tear resistance 2497.37 mN; density 1.52 g/cm3; and lightness L* 80.19. The results of microstructure observations using Scanning Electron Microscopy (SEM) were the paper with E. cottonii waste 15% seen less free space (tighter) than other papers. Based on the grammage and tensile resistance value, paper with E. cottonii waste 10% according to Indonesian National Standard 8218:2015 regarding paper and cardboard for food packaging requirements.

A Novel Flexible Liquid Metal Microheater with a Textured Structure.

In this paper, we propose a novel liquid metal microheater utilizing a textured structure. This microheater effectively solves the problem of the liquid metal in the PDMS flow channel fracturing at a certain temperature and significantly increases the maximum operating temperature that can be achieved by the current liquid metal microheater. Experimental results demonstrate that this new structured microheater can achieve a maximum operating temperature exceeding 300 °C. To explain the performance improvement and the reasons behind liquid metal fracture, corresponding experiments were conducted, and explanations were provided based on the experimental results. Subsequently, we verified the mechanical flexibility of the microheater and found that it exhibits excellent tensile and bending resistance. Finally, utilizing its good mechanical flexibility, the microheater was successfully attached to the side wall of a cup, resulting in the boiling of water.

Tuning microstructures of polyacrylonitrile-based carbon fibers by catalytic influence of boron for enhancement of mechanical properties and oxidation resistance

Boron catalytic graphitization of carbon fibers (CFs) is an effective methodology for reducing energy costs with the enhancement of tensile and oxidation resistance properties by re-constructing the crystal structure of CFs. Herein, a microwave plasma graphitization system for boron catalytic graphitization was devised. The effect of boron on microstructure and properties of CFs during boron catalytic graphitization process was investigated and analyzed. The mechanism of boron doping in different graphitization times was proposed. Furthermore, the results show that the tensile properties and oxidation resistance of CFs are improved and directly related to the microstructure of CFs, which depends on the different boron catalytic graphitization stages. This work provides the effect of boron on microstructure and properties of CFs during microwave plasma catalytic graphitization in different graphitization times and has important implications for deeply understanding the boron catalytic graphitization process which is beneficial for the preparation of CFs with excellent performance.

Effect of drawing speed on the deformation characteristics, microstructure and properties of copper wire rod

Currently, copper-based wire has been extensively applied in the information industry and for signal transmission due to its excellent performance in practice. Drawing speed, as a key parameter of the drawing process, has a significant impact on the production and quality of the wire. In this study, both simulation and experiment are performed to explore the evolution of deformation and damage behavior of copper wire and its microstructural properties during the process of multi-pass continuous drawing, with the drawing speed set to the range from 60 to 300 m/min. This provides guidance on the production and process optimization of the wire. It is revealed in the study that the surface of the pure copper wire is deformed more significantly than the core region, and that there is a rise in the equivalent strain and damage occurring at different locations in the longitudinal section of the wire as the number of passes increases. With the drawing speed increasing, the strain and damage occurring in the core region are reduced, while the damage caused by severe deformation on the surface shows nonlinearity. When the drawing speed increases, there is a significant improvement in the strength of the dominant texture component <101> in the copper wire, and the grain size of the wire is significantly refined. In the meantime, there is an increase in the density of dislocation within the wire. The severity of distortion caused to the grain tends to decrease, and the grain boundary is gradually blurred. By increasing the drawing speed, the surface quality of the wire is improved. Apart from that, there is a slight increase in the tensile strength, DC resistance and electrical resistivity of the copper wire, despite a decline in the conductivity of the wire.

Exploring waste marble dust as an additive in cementitious grouts for semi-flexible pavement applications: Analysis and optimization using RSM

This research aims to explore the potential utilization of waste marble dust (MD) within cementitious grouts for applications in semi-flexible pavements, a hybrid pavement type combining the benefits of both flexible and rigid pavements. MD was used to replace cement (ranging from 0 to 25%), combined with w/c ratios of 0.35 to 0.50, in the formulation of cementitious grouts. The assessment of grout characteristics encompassed evaluations of flowability and compressive strength (7d and 28d curing). Moreover, the microstructural characteristics of cement grouts incorporating MD were scrutinized through Scanning electron microscope-SEM and Energy dispersive X-Ray spectroscopy-EDS analyses. Additionally, response surface methodology (RSM) was used for experimental design, analysis, and the optimization of the factors (MD and w/c ratio). The significance of the model was examined through various statistical indicators. The optimal composition of cementitious grouts was determined using optimization technique within the RSM framework. Furthermore, optimal grout combinations were employed in fabricating semi-flexible mixtures and evaluated for Marshall stability, moisture susceptibility, indirect tensile stiffness modulus, dynamic modulus, compressive strength, and resistance to fuel spillage. The results indicated that an optimal combination of 15% waste marble dust and a 0.40 w/c ratio was identified through optimization techniques within the RSM methodology. Furthermore, Analysis of variance formula-ANOVA outcomes exhibiting a higher R² value (>0.80) and higher adequate precision (>4.0) underscore the significance of the proposed models, revealing a robust correlation between experimental and predicted data. The semi-flexible mixtures also showcase superior performance in terms of Marshall stability, stiffness, dynamic modulus, moisture resistance, and resistance to fuel spillage. Moreover, the integration of waste marble dust in cementitious grouts for constructing semi-flexible pavements not only addresses disposal concerns but also contributes to environmental sustainability.

Effect of solution treatment on porosity, tensile properties and fatigue resistance of Al–Cu alloy fabricated by wire arc additive manufacturing

This work studied the effect of solution heat treatment on the microstructure and properties of the Al–Cu alloy fabricated by wire arc additive manufacturing (WAAM), and focused on the influence of porosity and second phase evolution on the tensile properties and fatigue resistance of the alloy. The results show that with solution heat treatment at 530 °C for 1h, Al–Cu alloy fabricated by WAAM with low porosity (2.4 %) and high peak hardness (148.2 HV) can be obtained. Higher solution temperatures significantly increased the porosity, and extending the solution time caused the problems of increased porosity, micropore growth, microcracks as well as cavity. Influence of porosity on fatigue resistance is more significant than that on tensile properties. The results of tensile tests suggest that the effect of porosity on the strength of T6-treated alloy is limited and much smaller than that of the precipitation strengthening induced by precipitates, while the results of the fatigue crack propagation tests imply that porosity plays the dominant role in the fatigue crack propagation behaviors of the T6-treated alloy.

Enhancing rheological and aging performance of matrix asphalt through thermoplastic phenol-formaldehyde resin-based intercalated clay nanocomposites: Mechanisms and effects

This research presents a comprehensive investigation into the development of advanced asphalt materials fortified with PF/OMMT nanocomposites, emphasizing the synergistic effects of melt blending and nano intercalation. Through meticulous characterization, including SEM, FT-IR, and XRD analyses, the study unveils the microstructural evolution, affirming the formation of highly oriented interlayer structures within the asphalt matrix. The incorporation of OMMT, known for its hydrophobicity, significantly enhances the interfacial interactions between PF and asphalt, thereby bolstering the material's mechanical resilience, specifically its tensile, shear, and high-temperature rutting resistance properties. The presence of PF imparts notable improvements in the asphalt's thermal stability and aging resistance, attributed to its inherent antioxidative properties and the establishment of a robust three-dimensional polymer network with OMMT. These advancements herald a promising avenue for the production of high-performance, durable asphalt with superior anti-aging characteristics, optimized for demanding environmental conditions and heavy-duty applications.

Failure factor of reinforced layer for fiber-wound composite pipe under different loads

This study examined the failure mechanism of fiber-wound composite pipe and determined the optimum winding angle. Simulation models of glass fiber-wound composite pipe were established. Failure factor of the reinforced layer of fiber-wound composite pipes under internal pressure, torsion, axial tension and bending load are investigated in conjunction with the three-dimensional Tsai-Wu failure criterion. The results show that the winding angle has a significant effect on the stress distribution of the reinforced layer. The inner layer of the reinforced layer is prone to failure under internal pressure. The outer layer of reinforcement layer under torsion is the easy failure position. The failure-prone layer under tensile load is related to the winding angle. The inner layer of the reinforced layer is prone to failure when the winding angle is less than 60°, and the outer layer is prone to failure when the winding angle is more than 60°. The outer reinforced layer is prone to failure under bending loads. When the winding angle is less than 50°, the easily failed failure position is on the inside of bending. When the winding angle is greater than 50°, the easily failed position is on the outside of bending. The smaller winding angle is conducive to improve the tensile, bending and torsion resistance of the composite pipe. The larger winding angle is beneficial for improving resistance to internal pressure. The optimal winding angle range for each load is different and multiple winding angles should be used in the design to obtain a higher overall load carrying capacity. The research results can provide a theoretical basis for the improved design, manufacture and evaluation of fiber-wound composite pipes.

Component method for bolted SHS end plate splice joints loaded in tension

Bolted end plate connections are traditional solutions for splice joints with square hollow sections (SHS). A cover plate could be used on one side or two adjacent sides of SHS where the end plate is flushed, resulting in two types of asymmetric splice joints. The advantage of the asymmetric joints is that no space is required between the façade panel and the member surface whilst the easy assembly feature remains. The component method is used to design the bolted end plate connection, as stipulated in prEN 1993–1–8. However, the design rule is only available for connections with open cross-sections. In this paper, a modified component method for predicting the tensile resistance (end plate fails with failure mode 1 according to prEN 1993–1–8) and stiffness of the asymmetric bolted SHS end plate splice joints is proposed. First, a parametric study is carried out to develop the component method for the traditional symmetric bolted SHS end plate splices based on the validated finite element (FE) model. Next, a simplified two-dimensional FE model is employed to evaluate the effect of the asymmetric feature on the stiffness of the joint. Finally, a parametric study is carried out on two types of asymmetric joints to validate the interaction model of individual components. The resistance and stiffness of the asymmetric end plate splice joints are well predicted using the modified component method.

Utilizing jackknife and bootstrap to understand tensile stress to failure of an epoxy resin

A study was conducted on the tensile stress of an epoxy resin (Resoltech® 1050/1056). This was done by gathering a sample of 39 tensile strength data under consistent levels of stress. The tensile stress resistance is often characterized using a three-parameter Weibull distribution and the reliability of this characterization, given by confidence intervals (CIs). This approach commonly utilizes data-resampling techniques to estimate the CI of its parameters. CIs are constructed from six existing point-estimation methods. Herein, the jackknife was carried out to calculate the CIs using 39 subsamples and bootstrap methods using 100 or 200 subsamples. To date, there have been no studies exploring the effectiveness of subsampling methods for constructing CIs related to tensile strength. In this study, jackknifed and bootstrapped samples are used to implement the percentile method and three variations of the bias correction methods. We then performed simulations to evaluate the reliability of these methods using a Weibull random number generator. Our results showed that while the bias-corrected approach generated the most stable CIs from replicate samples, its accuracy was contingent on the point-estimation method employed. We also found that the different methods for calculating CIs resulted in significantly varying widths of the CIs.

Comparing the mechanical properties of single and double layer 100% cotton denim fabrics for motorcycle protective clothing

India has one of the highest rates of motorcycle accidents in the world. Protective clothing is required for motorcyclists in India since it can lessen the severity of injuries sustained in an accident. The purpose of this research is to examine the performance of single and double layers of denim fabrics developed. Focusing on the potential use in motorcycle protective clothing, 100% cotton single-layer (SL) fabrics with masses ranging from 370, 390, 410, 430, and 450 g/m2 are developed. The 100% cotton single-layer (SL) fabrics are taken as double layers (DL) for testing and analysis. Both single and double-layer fabrics were tested for physical properties and mechanical properties such as tensile, tear strength, and abrasion resistance. Overall performances of double-layer (DL) fabrics were superior compared to that of single-layer fabrics since double-layer fabrics contain two layers of fabrics to withstand stress and tear, and also provide better abrasion resistance.

Strain rate sensitivity of strain‐hardening fiber‐reinforced concrete subjected to dynamic direct tensile loading

AbstractThis study investigates the effects of matrix strength on the high‐rate tensile resistance and strain rate sensitivity of strain‐hardening fiber‐reinforced concretes (SHFRCs) under direct tensile loading. Two types of deformed steel fiber, hooked and twisted, were reinforced in two matrices, high‐performance concrete (HPC) with compressive strength of 84 MPa and ultra‐high‐performance concrete (UHPC) with compressive strength of 180 MPa. Additionally, an artificial neural network (ANN) based model was proposed to estimate the strain rate sensitivity of SHFRCs subjected to dynamic direct tensile loading. The results showed that HPC produced relatively lower post cracking strength but much higher strain capacity at a high strain rate than UHPC. Moreover, HPC was found to be more strain rate sensitivity than UHPC. Furthermore, the proposed ANN model was an efficient tool for predicting the strain rate sensitivity of SHFRCs. Based on the sensitivity analysis, the contribution of each influence factor on the final strain rate sensitivity of SHFRCs can be determined.

Super silkworm cocoons constructed by multi-silkworm larvae: Promising composites with dense structures and excellent mechanical properties

A normal silkworm cocoon (NSC) with a unique nonwoven structure is usually spun by a single silkworm larva. Notably, there is a special Bombyx mori genetic resource that many (three or more) mature larvae tend to collectively spin into one cocoon, which was named “multi-silkworm cocoon” (“MSC”). However, the MSCs display loose structure and poor mechanical properties which limits their further application. In this study, a series of hybrid silkworm cocoons (HMSCs) are obtained by hybridizing “MSC” with a selected commercial silkworm strain successfully. The morphology, microstructures, and mechanical properties of cocoons constructed by one to three silkworm larvae were characterized and compared. The results indicated that about 48.3 % of silkworm larvae could create double and triple cocoons in the F1 generation of the silkworm hybrid, displaying robust fiber networks and dense structures. The mechanical characteristics of the HMSCs, including the tensile, peeling, compression, and needle penetration resistance properties, exceeded those of MSCs, showing significant application potential for high-performance bio-composites. This study provides a practical approach for obtaining silkworm cocoons with controllable structures and mechanical properties to develop and fabricate natural composite and biomimetic materials.

Optimizing techno-functionality of germinated whole wheat flour steamed bread via glucose oxidase (Gox) and pentosanase (Pn) enzyme innovation

Germination, a powerful biofortification technique, holds immense potential in bolstering the micronutrient profile of essential staple grains, thereby paving the way for optimal nutritional enhancement. The primary goal of this study was to improve the technological functionality of germinated wheat flour by incorporating pentosanase (Pn) and glucose oxidase (Gox) enzymes, with particular emphasis on the evolutionary changes in its components. The inclusion of Gox did not produce any substantial impact on the volumetric characteristics of the steamed bread. The incorporation of Pn and Gox has been seen to enhance the overall excellence of steamed bread by optimizing loaf volume and textural characteristics while also improving the thermal stability of the dough. The existence of two endothermic peaks could be attributed to bound water or alterations in the granules within the starch crystallization region. Adding Pn and Gox reduced and increased the formation and stability time of the dough, respectively. A certain ratio was employed to assess alternations in the crystallinity of starch granules over a limited range. After steaming, a significant decrease in IR1047/1022 was observed, indicating that the elevated temperature partially disrupted the internal starch crystal structure, leading to a gelatinization reaction with water. The ratio of tensile resistance (R) and elongation (E) of dough increased significantly compared to the control. The results obtained from this study indicate that the simultaneous inclusion of enzymes (Pn + Gox) holds significant promise for expanding the technological functionality of germinated wheat flour dough and improving the quality attributes of steamed bread.

Progressive collapse analysis and retrofit of a steel-RC building considering catenary effect

Despite their low probability of occurrence, the consequences of abnormal loads may be very important, both in economic terms and in terms of human lives. This has stimulated the development of strengthening and retrofitting techniques to mitigate the risk of progressive collapse of buildings. However, their application to real-scale buildings is still lacking. This paper describes the progressive collapse analysis and retrofit of a steel-reinforced concrete hospital building. The progressive collapse performance under different column removal scenarios is investigated using both nonlinear static and dynamic analyses. A two-step pushdown analysis procedure is developed to estimate the dynamic amplification factor (DIF) to partially compensate for the dynamic effects. The results have revealed the vulnerability of the building due to the low tensile axial resistance of the beam-to-column connections. Both the hypothesis of DIF = 2 and the almost inversely proportional relationship between DIF and vertical deflection have proven to be ineffective due to the catenary effect. A retrofit solution is proposed based on an outrigger-belt truss system on the rooftop level. The results show the effectiveness of the retrofit strategy. The displacement dynamic response of the retrofitted structure is significantly reduced if compared to the original structure since it goes from about 20 cm to less than 1 cm. However, the tensile strength of column-to-column connections of the top three floors is inadequate and should be increased. To this aim, a strengthening intervention is developed to increase the tensile strength from 565 kN to 965 kN, thus allowing the tensile axial forces caused by the column removed to be resisted.