Search

Steel shear wall (SSW) is an efficient system used to construct and improve many structures over the past decades. The main weakness of the traditional flat plate SSW is the premature buckling of the plate, for which the corrugated steel shear wall (CSSW) is a suitable alternative. However, the reduced resistance of CSSW compared to flat SSWs is a disadvantage. In this research, their reinforcement by flat steel plates with different dimensions and thicknesses has been used to improve the behavior of vertical trapezoidal steel shear walls (VTSSW). The samples studied in this research were subjected to cyclic loading after verification in Abaqus finite element software. The outcomes showed that reinforcing CSSWs with flat plates increased strength and energy absorption between 6 to 63% and 16 to 92%, respectively. Also, the equivalent viscous damping has increased between 5 and 82%. Also, due to strengthening the CSSWs, the pinching phenomenon in the hysteresis curves has been reduced, and the sudden decrease in strength after buckling in the CSSWs without stiffener has been significantly reduced. [ABSTRACT FROM AUTHOR]

This article takes STC long and short columns as the research objects, and first conducts quasi-static tests to preliminarily explore the failure characteristics of STC long and short columns under horizontal reciprocating loads. Then, a large number of numerical analysis models are established to explore the influence of coaxial compression ratio, steel pipe wall thickness, wood cross-sectional area, and bending point height on the seismic performance of STC long and short columns through numerical analysis. The results indicate that although the trend of changes in STC long columns and short columns under these factors is the same, STC long columns mainly resist bending and compression, while STC short columns mainly bear shear and bending resistance. Finally, the calculation formulas for the compressive bending bearing capacity of STC long columns and the shear bending bearing capacity of STC short columns were derived through theoretical analysis. The accuracy and safety of the formulas were verified through a large number of numerical simulation results. [ABSTRACT FROM AUTHOR]

Many existing reinforced concrete buildings have been designed based on earlier codes of practice that underestimated seismic forces, making them vulnerable to damage during seismic action. Equipping existing buildings with shear links and eccentric braces is one of the available seismic retrofitting methods to dissipate seismic energy away from the main structural members. In this paper, a proposal for the seismic retrofitting of two existing reinforced concrete buildings using aluminium shear links and steel braces is presented. First, a capacity-based design approach is followed to determine the required sizes of the shear links and eccentric braces. Second, numerical analyses are used to compare how the original and retrofitted buildings responded. These tests include pushover analysis, nonlinear time-history analysis, damage analysis, incremental dynamic analysis, fragility and reliability analysis, and damage analysis. The results reveal that the proposed retrofitting method can sufficiently upgrade the performance level of the buildings and reduce their storey displacements and interstorey drifts, as shear links are found to absorb almost all seismic energy, therefore keeping other structural members responding elastically. Yet, using shear links alters the local behaviour of the surrounding structural members, which should be considered in the design process. Furthermore, compared to the original buildings, retrofitted buildings are expected to undergo less structural damage as they have lower damage indices. Meanwhile, the fragility of retrofitted buildings is significantly reduced compared to the original ones, which indicates the efficiency of the proposed retrofitting methods in upgrading the performance of seismically deficient reinforced concrete buildings. [ABSTRACT FROM AUTHOR]

The aim of the work was to obtain advanced oxide materials, obtained through technologies compatible with sustainable development materials. These materials are used in special operating conditions, such as in the case of continuous steel casting, where there is a temperature difference of over 10000C between the mold wall and the steel crust. These are the lubricating powders for the crystallizer. [ABSTRACT FROM AUTHOR]

In this paper, the structural performances of steel plate shear walls employing web plates with rectangular, triangular (zigzag), trapezoidal, and sinusoidal corrugation patterns under monotonic loading are investigated. Several significant structural response parameters including buckling stability, stiffness, strength, serviceability, and energy dissipation capability are considered in this research endeavor. The results of this study provide crucial insights into the behavior of corrugated-web steel shear walls with varying infill plate shapes and thicknesses. It is shown that corrugated-web shear walls predominantly undergo local and/or interactive buckling modes, while flat-web systems exhibit more of a global buckling behavior. Additionally, corrugated infill plates substantially enhance the overall capacity of the system, with the rectangular pattern exhibiting the highest strength, surpassing the flat-web panels by approximately 11 times for a 2-mm web-plate thickness. Assessment of the energy absorption capacity reveals the superior performance of the rectangular pattern for web thicknesses between 2.0 and 3.0 mm. From the load–displacement responses, it is found that increasing of the web thickness significantly enhances the strength and stiffness performances and the base shear capacity is improved by 42% while increasing the thickness from 1.5 to 3.0 mm. These results demonstrate the importance of proper design and detailing in ensuring the desirable and high performance of corrugated-web steel shear walls as promising lateral force-resisting systems. [ABSTRACT FROM AUTHOR]

Bubbled Reinforced Concrete (RC) slabs have gained popularity in recent years as a practical construction method that eliminates unnecessary concrete in the center, thereby reducing the dead weight of the structure. This study provides a systematic framework to compare the performance and capabilities of one-way bubbled concrete slabs reinforced with Glass Fiber Reinforced Polymer (GFRP) bars and embedded steel I-sections. Four one-way concrete slabs, each with a length of 2,600 mm and a rectangular cross-sectional area of 600 mm in width and 150 mm in depth were employed. These slabs were reinforced with Glass Reinforced Plastics (GRP) rebar at the same reinforcement ratio and tested by two-point bending to failure. Different parameters such as specimen type (solid or bubbled slabs) and internal reinforcement were achieved using steel I-sections in two different shapes (2 and 4 pcs of steel I-sections), where 4I-section shape with a cross-sectional area equivalent to 2I-section shape, channel shear connectors, and bent steel bars (10 mm diameter) were used to improve the shear resistance. The results showed that bubbled slabs experienced a higher range of deformations (including deflection, strains, and cracks) by about (28%-88%) and a 15% decrease in ultimate load capacity compared to solid slabs. On the other hand, the use of steel I-sections as internal reinforcement significantly improved the specimen performance compared to unreinforced slabs (Steel Slab (SS) and Bubbled Slab (BS), respectively). Deflection was reduced by approximately 52% and 87% at the same load level, ultimate load capacity increased by approximately 121% and 179%, and flexural stiffness increased by approximately 197% and 272% at the same load level. [ABSTRACT FROM AUTHOR]

Historical seismic events have repeatedly highlighted the susceptibility of above-ground liquid storage steel tanks, underscoring the critical need for their proper design to minimize potential damage due to seismic forces. A significant failure mechanism in these structures, which play essential roles in the extraction and distribution of various raw or refined materials—many of which are flammable or environmentally hazardous—is the dynamic buckling of the tank walls. This study introduces a numerical framework designed to assess the earthquake-induced hydrodynamic pressures exerted on the walls of cylindrical steel tanks. These pressures result from the inertial forces generated during seismic activity. The computational framework incorporates material and geometric nonlinearities and models the tanks using four-node shell elements with two-point integration, specifically Belytschko shell elements. The Arbitrary Lagrangian–Eulerian (ALE) method is employed to accommodate substantial structural and fluid deformations, enabling a full simulation of fluid–structure interaction through highly nonlinear algorithms. Experimental test data are utilized to validate the proposed modeling approach, particularly in replicating sloshing phenomena and identifying stress concentrations that may lead to wall buckling. The study further presents results from a parametric analysis that varies the height-to-radius and radius-to-thickness ratios of a typical anchored flat-bottomed tank, examining the seismic performance of this common storage system. These results provide insights into the relationship between tank properties and mechanical behavior under dynamic loading conditions. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

High-strength steel has been extensively used in numerous structures or high-rise buildings because of its high strength, ductility, and weldability. However, high-strength steel structures are vulnerable to fire hazards, so the ability to predict structural behavior is crucial in structural fire safety design. Creep behavior is one of the primary factors influencing the response of steel at high temperatures. This paper presents numerical studies using the fire dynamics simulator (FDS) and finite element method (FEM) coupling models to predict the structural behavior of a protected beam with a cavity for H-SA700 high-strength steel at elevated temperatures, including the creep effect. A comparison between simulation and experiment results demonstrates the validity of the process. In detail, based on a set of tensile tests conducted at six constant temperatures between 23°C and 600°C, the creep model is proposed. Subsequently, because creep is temperature-dependent, the heat transfer model used to predict the temperature distribution of the steel is developed. The effect of the partially damaged protection cover is discussed. Finally, it is found that with the temperature distribution from FDS-FEM integration and the proposed creep models, the collapse time of the beam can be defined. This study provides a practical approach for developing the creep model without creep tests and applying it to complex structures during fires. [ABSTRACT FROM AUTHOR]

A steel brace is effective to retrofit old reinforcement concrete (RC) buildings by increasing the horizontal load capacity of structures. However, concrete cracks that easily occur in the surrounding RC members under tension initiate early strength degradation, so this research aimed to develop a new self-centering brace (SCB) with the compression-only capacity such that no tension force is developed in the brace or to the adjoining RC members. Original SCBs have been developed to reduce the residual deformation of structures with a symmetrically flag-shaped hysteretic response. By altering the force transfer mechanism in the original SCB, a compression-only self-centering brace (C-SCB) can be developed under a symmetrically reversed cyclic loading, providing an alternative for the RC building retrofit. This paper first introduces the mechanics and deformation mechanism of the proposed C-SCB. A test program is then conducted on the cyclic tests of a buckling-restrained energy dissipating bar (EDB) to evaluate the energy dissipation. A 3,695-mm-long C-SCB is composed of posttensioning high-strength steel tendons, steel compression members, and buckling-restrained EDBs for the energy dissipation. The C-SCB in tests showed a good compression-only self-centering capability up to an axial displacement of 31 mm, with a maximum axial force of 1,530 kN. No damage of the steel tendons, compression members, or EDBs was found after three phase tests. Finite element analysis further validated the compression-only hysteretic response and mechanics of the C-SCB in a symmetrically reversed cyclic loading. [ABSTRACT FROM AUTHOR]

Residual stress (RS) significantly impacts the mechanical performance of components. Measurement of RS often provides incomplete data in terms of components of stress and spatial density. Employing such fields in finite element simulations results in significant modification of the field to achieve equilibrium and compatibility among strains. To overcome this, an iterative stress reconstruction algorithm (ISRA) is developed to estimate 3D RS fields that satisfy equilibrium, are stress component-wise complete, and represent the characterized data sampled. An Al 7075-T651 plate and an additively manufactured (AM) A36 steel wall are considered for RS reconstruction using measurement data from the literature. A maximum variation of ~2.5 MPa in the Al plate, and ~10 MPa in the steel wall are observed between the reconstructed and measured stresses. Furthermore, unknown stress components emerge and reach significant magnitudes (upto ~2.3 MPa in the Al plate and ~45 MPa in the AM wall) during ISRA. Indeed, it is found that minor errors in measurement or data processing are eliminated through the physical requirements during ISRA. Employing a reconstructed RS field is hence not just more accurate given its compatibility, but it additionally corrects for minor errors in measurement. Furthermore, it is found that spatially dense measurement data result in convergence with fewer iterations. Finally, although ISRA yields a nonunique solution dependent on boundary conditions, measurement errors, fitting errors, and mesh density, it accommodates for uncertainties and inaccuracies in measurement, as opposed to failing to reach a physically realistic converged solution. [ABSTRACT FROM AUTHOR]

To study the lateral performance of a cold-formed steel–concrete insulation sandwich panel composite wall, two full-scale specimens with different arrangements were designed. The specimens underwent cyclic loading tests to examine the failure characteristics of the composite wall, and lateral performance aspects such as the experimental hysteresis curve, skeleton curve, and characteristic value of the whole loading process were acquired. The experimental results indicate that the failure of the composite wall system was primarily caused by the failure of the connection; the overall lateral performance of composite walls with one wall panel at the bottom and two wall panels at the top (W1) was superior to that of composite walls with two wall panels at the bottom and one wall panel at the top (W2). When loaded to an inter-story drift ratio of 1/300, the composite wall did not exhibit any significant damage. A finite element (FE) model was developed and validated by the experiments. Factors affecting the shear bearing capacity were analyzed based on the FE model, including the yield strength of diagonal braces, the thickness of the diagonal braces, the arrangement pattern of the wall panels, the dimensions of the wall panels, and the strength of the connection of the L-shaped connector and the flat connector. The FE results show that all these factors can influence the lateral performance of the composite wall. [ABSTRACT FROM AUTHOR]

Magnetic Permeability Perturbation testing (MPPT) has the advantage of high sensitivity for deeply buried defects in steel pipes. However, in complex working conditions, variations in the partial wall thickness of the pipe can affect the defect detection results. The paper discusses the influence mechanism of uneven wall thickness on the MPPT of internal defects on steel pipes and analyzes the magnetic field distribution caused by uneven wall thickness which influences on the magnetic permeability perturbation (MPP) of internal defects. The MPP is enhanced at the thinning wall and weakened at the thickening wall. The effect of uneven wall thickness on MPPT signals is confirmed through simulation and experiment. The signal of defects in thinning wall is enhanced, while the signal of defects in thickening wall is weakened. The greater the wall thickness variation, the degree of signal distortion is more significant. Experimental results show that uneven wall thickness has an effect on the detection of the defects with different depths. Finally, a method using deep saturation magnetisation is proposed to mitigate the inconsistent signals caused by uneven wall thickness. The findings will contribute to quantitative evaluation of defects in MPPT. [ABSTRACT FROM AUTHOR]

Flat plate structures consist of a slab supported directly by columns without beams or drop panels, resulting in a thinner slab with more efficient use of space. Despite these advantages, a flat plate slab is subjected to brittle punching shear. Sudden collapse may occur when a column pushes a piece of concrete from the slab above it. This paper displays Finite Element Analysis (FEA) using ABAQUS/ CAE 2019 to simulate the punching shear impact on a flat plate strengthened with horizontal steel bars of varying number and diameter, located at the compressive side of the slab. A numerical model was constructed with 8-noded hexahedral 3D brick elements for concrete and 2-noded linear 2D beam elements for steel reinforcement. The model was adapted based on experimental data. A parametric analysis was conducted to evaluate the impact of placing horizontal steel bars at the compression side of the flat plate and changing the quantity and size of these bars on the slab's performance. The results illustrate that the shear capacity increases from 17.07% to 28.13% as the bar diameter increases and from 19.17% to 54.82% as the number of bars increases. [ABSTRACT FROM AUTHOR]

The novel precast hybrid coupled wall structure system considers convenience requirements for the production and construction of prefabricated components. In this study, to determine the ultimate shear strength of embedded beam-to-wall connections, four full-scale specimens were meticulously designed using the "weak connections and strong components" methodology. Under low-cycle loading on a coupling steel beam, the experimental results indicated that the shear strength of the specimen was approximately twice that predicted by the Mattock–Gaafar mechanical model employed in Seismic Provisions for Structural Steel Buildings (ANSI/AISC 341-16). Therefore, a mechanical model was established to analyze the force transfer between the steel beam and concrete wall. Finally, design formulas for the shear strength were proposed, in addition to corresponding suggestions for construction reinforcement in the embedded area and adjacent zones. [ABSTRACT FROM AUTHOR]

AbstractTo dampen the loading sequences in the constructions, using the shear walls is recommended. Shear walls, which withstand the lateral forces (i.e., parallel to the plane of the wall) of wind and seismic activity, prevent buildings from collapsing while columns and load-bearing walls support the structure’s compression load all the way to the foundation. Besides, some new techniques are innovated for strengthening the structure like outrigger system. The steel shear walls are mostly used in the steel structures due to their high strength, ductility, and low weight. Recently, implementing Corrugated Steel Shear Walls (CSSWs) has gained more attention because they can absorb much amount of energy compared to flat steel shear walls. There are two important parameters in the CSSWs that play crucial roles in controlling their strength; corrugation geometry and orientation. Therefore, the current research paper aims to study numerically the effects of four corrugation geometries (trapezoidal, square, zigzag, and curved) with two orientations on the cyclic behavior of the CSSWs. Finite Element Analysis (FEA) is used to simulate the seismic loading conditions and finally, this procedure is validated through the comparison of the modeled flat shear wall with the experimentally published results. The difference between the peak loads of hysteresis curves obtained numerically and experimentally is about 8.5%. The stated FEA procedure in this paper can be regenerated by other researchers. The results confirmed the applicability of the CSSWs compared to the flat shear walls. Also, the vertical corrugation infill patterns result in higher strength in comparison to the horizontal ones. For instance, in the zigzag and square corrugation shapes, the plastic energy dissipation of the vertically oriented specimens (13.84 and 14.01 KJ, respectively) is higher around 7% and 29%, respectively than the horizontally oriented ones (12.9 and 10.84 KJ, respectively). Besides, the trapezoidal and curved corrugation geometries show the highest cumulated energy and plastic energy dissipation. [ABSTRACT FROM AUTHOR]

A demising wall assembly that is frequently being specified for mid-rise and high-rise building constructions is a double steel stud wall assembly with one or more sheets of fire rated gypsum board installed inside the wall cavity between the rows of studs, creating a triple leaf wall. Locating the gypsum board inside the wall cavity can sharply decrease the transmission loss below the 200 Hz one-third octave band due to the creation of two mass-air-mass resonances centered around the 80 Hz onethird octave band. For the walls tested as part of this study, this decrease in the transmission loss was 14 to 17 dB. One theory for why gypsum board is being specified inside the wall cavity is the belief that the gypsum board in the wall cavity maintains the transmission loss of the wall even if residents create small holes in the outer gypsum board layers by hanging decorations on the wall or securing furniture to the wall. To disprove this theory, an increasingly larger number of holes were drilled into the gypsum board on both sides of a wall to determine the effect on the transmission loss. It was found that a significant number of holes, well in excess of normal use of a wall needed to be drilled into the gypsum board before the transmission loss was affected. [ABSTRACT FROM AUTHOR]

The aim of this study was to find a way to improve earthquake resistance performance more effectively through various reinforcement methods between a cabinet bottom and concrete slab, which is a vulnerable connection in the event of earthquake. In order to improve the earthquake resistance performance of an electric cabinet, methods such as installing a vibration isolation device, increasing the number of connecting bolts between the cabinet bottom panel and base channel, welding a steel grid to the cabinet bottom panel, and so on, were considered and, in order to compare the performance in each case, a three-axis shaking table test was performed. As a result of comparing the seismic performance of each case according to the acceleration response, it was found that the reduction of seismic force was best when applying the vibration isolation device. However, there is a disadvantage in that the spatial and temporal limitations are large and the unit price is high for application in the field. For this reason, it is predicted that the method of ensuring the higher rigidity of an electric cabinet by increasing the number of connecting bolts, as proved through this study, would be a more economical and realistic seismic performance method in field applications. [ABSTRACT FROM AUTHOR]

This paper presents the performance-based fire safety analysis of steel structures of padel-center built in Nokia, Finland. The analyses are conducted using advanced calculation models (fire simulations using Fire Dynamics Simulator, FDS, and finite element method, FEM, based analyses of the steel frames in elevated temperatures using SAFIR software, including joint analysis) in support with less sophisticated models (critical temperatures of steel members). The following localized fire scenarios are studied: lounge area furniture fire (4 sofas), sporting equipment fire (10 sporting bags filled with flammable clothing), fire during maintenance (scissor lift fire with miscellaneous temporary fire load) and a fire on HVAC balcony near the trusses. The aim of the paper is showcase recent developments in design processes and methods that are in practical use today in performance-based fire design (PBD), to demonstrate that relatively extensive performance-based studies can be (commercially) viable also in relatively small and mundane steel buildings, and to present a fairly robust framework for PBD of similar steel structures. As a result of the performance-based design, most of the steel structures in the case building could be constructed without fire protection, but some critical structures were identified and protected to class R30. The proposed design was approved by the local municipal authorities. [ABSTRACT FROM AUTHOR]

In order to study the seismic performance of cold-formed, thin-walled C-shaped steel composite wall, a set of cold-formed thin-walled C-shaped steel skeleton structure and a set of composite wall covered with fireproof straw boards on both sides were tested with a low cyclic alternative load. The seismic performance indexes, such as bearing capacity characteristic value, lateral stiffness, ductility coefficient, energy dissipation coefficient and stiffness degradation, were analysed by obtaining the backbone curves of each group of specimens. The effects of fireproof straw boards on the seismic performance of the composite wall were compared, and a mechanical analysis model of the cold-formed thin-walled C-shaped steel composite wall was established by using ANSYS/structural finite element software. The results show that the damage patterns, backbone curves and capacity characteristic values of the finite element model are in general agreement with the tests. The bearing capacity and lateral stiffness of the light steel skeleton structure without boards is very low, while the bearing capacity of the composite wall with straw boards on both sides is significantly increased. The lateral stiffness increased by 10.76%, the ductility coefficient increased by 27.34% and the energy dissipation coefficient decreased by 45.8%. [ABSTRACT FROM AUTHOR]

The article presents tests aimed at optimising the welding of bars, made of steel AISI1005 (ø 4.2 mm), in a cruciform configuration (i.e. using the cross-wire welding process). The authors identified research gaps and carried out a detailed numerical analysis of these cases. The research-related calculations involved the use of SORPAS software. The new areas of research included (i) bars with protective zinc coatings having various thicknesses of 0 µm, 5 µm, 10 µm and 30 µm, (ii) various welding current rise times (up-slope) and (iii) single and multi-pulse welding cycles. The tests were carried out using a DC 1 kHz inverter welding machine; the results concerning welding up-slope times were compared with those obtainable using a conventional AC 50 Hz welding machine. The results of the study, in the form of a welding technology with various values of up-slope time, have been implemented in industry. The inventive idea is protected by patent no. P.229445 at the Polish Patent Office. [ABSTRACT FROM AUTHOR]

The flexural behavior of hybrid timber–steel encased beams comprising coniferous radiata pine (Pinus radiata) (MGP10) and Douglas fir (Pseudotsuga menziesii) (F8) timber lamellae with bonded-in steel bars is studied. The effect of cross-section depth, steel bar size, timber species/grade, and steel bar arrangements (only bottom and top-and-bottom) on the hybrid beams' stiffness, failure mode, ductility, and load-carrying capacity were investigated. The flexural capacity and stiffness of the doubly (top-and-bottom) reinforced beams are increased by 127% and 71%, respectively. However, in the singly (bottom) reinforced beams, the flexural capacity and stiffness are increased only by 41% and 25%, respectively, highlighting the important role of the compressive bars. The failure of all beams was associated with tensile flexural failure of timber, but the steel bars improved the ductility of the beams. The maximum coefficient of variation of the peak load in hybrid beams (CoV=14.3%) is lower than that of the bare timber beams (CoV=21.7%). Two analytical models were developed based on a linear and a bilinear stress–strain relationship for timber. The analytically predicted peak load and stiffness agree well (less than 13% and 12% difference) with the experimental results. [ABSTRACT FROM AUTHOR]

Three concrete buildings with six storeys above ground and two basements have been designed in detail according to the first generation of Eurocodes 2 (including structural fire design) and 8, as well as the official drafts of their second generation counterparts as of the end of 2023. In one horizontal direction the buildings have a wall-, frame-equivalent-dual- or frame-lateral-load-resisting system; in the other, the first two buildings have a wall-system and the third a wall-equivalent-dual. The design seismic action is in all cases according to the current generation Eurocode 8, scaled to a peak ground acceleration on rock of 0.2 or 0.3 g. Seismic design is for ductility class (DC) Medium (M) of the current generation or DC 3 of the new one, which have the same behaviour factors, q, in all structural systems considered; so, in each building seismic action effects from the analysis are the same for the two Eurocode generations. All designs are assessed through nonlinear response history analysis (NLRHA), carried out according to the pertinent Eurocode 8 rules. Designs according to the second generation meet the performance goals of Eurocode 8 much better and transparently than with the first generation, but use markedly larger steel quantities and indeed often unnecessarily so, especially for confining reinforcement—which sometimes comes out in quantities that cannot be placed. Proposals are made for a more rational linkage of local ductility demands with the q-factor and implemented in alternative second generation designs. Minor changes to the new generation's design/detailing rules for ductile walls are also proposed and implemented in these alternative designs; they prove only partially effective in resolving certain deadlocks originating from poorly justified detailing rules that produce unnecessary and counterproductive wall flexural overstrengths. The new generation Eurocode 8 lacks design rules for the free height of ductile walls within rigid basements, which is a weak link, very likely to fail under the high shear force which balances the wall's moment resistance at the top of the rigid basement. NLRHA confirms that the alternative provisions proposed for second generation Eurocode 8 give more cost-effective designs than the first generation, with better overall performance at about the same or even lower cost. [ABSTRACT FROM AUTHOR]

This paper compares two methods for retrofitting an existing hospital concrete structure to improve its seismic performance: internal and external retrofitting. Internal retrofitting involves adding chevron braces, reinforcing shear walls with Fibre-reinforced plastic coating, and wrapping the walls, columns, and beams using steel jackets. External retrofitting uses two braced exterior steel frames connected to the concrete building using dampers. The paper also proposes a new design objective for hospital structures that ensures immediate occupancy performance level under earthquake hazard level-1 and prevents collapse under higher ground motion intensity. The paper evaluates the base structure, the two retrofitting schemes, and the proposed design method using pushover and nonlinear dynamic analyses under 20 selected earthquake records. The paper then compares the probabilistic seismic risk models using fragility curves. The results show that external retrofitting is more effective and economical than internal retrofitting and that the proposed design objective can significantly reduce the seismic risk of hospital structures. [ABSTRACT FROM AUTHOR]

The quality of construction projects is related to the safety of people's lives and property, and also has a greater impact on the stability of the entire society; factory structure is one of the most common productive buildings, and some factory buildings have been partially lost its using function due to a long service history; in order to ensure the safety, applicability and durability of these factory buildings and continue to utilize or strengthen these factory structures, it is necessary to perform safety testing and identification for factory buildings at the first time. Structural safety assessment is the process of inspecting, measuring, analyzing and evaluating the structural effects, structural resistance and their interrelationships and finally obtaining structural safety grade of buildings that have been built or in service for many years. On the basis of summarizing and analyzing previous research works, this article expounded the research background, current status and future challenges of building safety grade identification, elaborated material testing methods, specifications, frameworks and processes of security grade identification for factory structure buildings, analyzed the concrete strength and steel corrosion detection, structural seismic identification and bearing capacity calculation of factory building, and proposed corresponding reinforcement measures and discussed its reinforcement effect. The final identification results of an engineering case are in good agreement with its actual construction conditions and on-site inspections and basically satisfactory the results of the factory building structure. The study results of this paper provide a reference for the further researches on the safety grade identification and reinforcement effect of the factory structure building. [ABSTRACT FROM AUTHOR]

Over the last fifty years, a number of higher energy X‐ray sources have been suggested as alternatives for the usual AlKα source found in the first commercial XPS systems and still the standard anode material for XPS today. This paper reviews the development of a number of such sources, predominantly in the authors' laboratory, and the rationale behind the desire to extend the binding energy range of the technique. The achromatic sources SiKα, ZrLα and TiKα are described along with monochromatic sources AgLα and CrKβ, both based on the standard quartz monochromator geometry but taking higher orders of diffraction. The driving force for much of this development was the desire to probe deeper core levels and CCC Auger transitions. These could be combined into initial or final state Auger parameters as described in much of the work cited in this review. The highest energy source considered is the CuKα source based around an external X‐ray tube, which provides much insight into the electronic structure of steels by measurement of the Fe1s and FeKLL peaks. The last decade or so has seen a significant increase of interest in HAXPES, and all manufacturers of turn‐key XPS instruments offer HAXPES options of one form or another, there are three dedicated HAXPES systems commercially available, which are very briefly described. [ABSTRACT FROM AUTHOR]

Early CO2 curing acting as a new curing technique is an effective way to cut down on carbon footprint in cement industry. It also improves the strength development and long-term durability of concrete without reinforcement. Given the fact that reinforcement concrete is most widely used in construction and building fields, the carbon sequestration potential will be enhanced remarkably if this curing technology can be used in reinforced concrete. However, the impacts of early CO2 curing on the corrosion behavior of steels, which is the major concern for reinforced concrete exposure to chloride, is unclear yet. In this work, the permeability of chloride, threshold chloride value and corrosion behaviors of steels in cement mortar were determined to comprehensively study the effect of early CO2 curing on the chloride induced corrosion of steels. Early CO2 curing lowers the chloride ions permeability of mortars, in particular for the mortars with 28 day curing ages. Steels take longer time to form stable passive films in early CO2-cured mortar than in conventional moist-cured ones. Early CO2 curing reduces the chloride threshold concentration of mortar, in particular for the mortars that the whole cross section is carbonated, the reduction reaches ∼50%. However, it exerts few effects on corrosion induction phase of steel rebar. Moreover, early CO2 curing decreases the corrosion rate of steel bars in corrosion propagation phase and thus the overall corrosion rate of steels during the whole testing process due to slower chloride ingress rate. Thus, early CO2 curing can act as an alternative curing technique in the production of pre-cast reinforced concrete exposed to chloride. [ABSTRACT FROM AUTHOR]

Summary: To investigate the influence of using high‐strength steel bars in columns on the seismic resistance capacity and seismic resilience of frame structures, seismic fragility evaluation of three 8‐story reinforced concrete (RC) frame structures was conducted based on the incremental dynamic analysis (IDA) using 11 ground motion records. The main parameter is the longitudinal reinforcement configuration in the frame columns, where the first structure is reinforced with HRB 600 grade steel bars in the columns, the second structure is replaced with equal area ultra‐high‐strength (UHS) steel bars (i.e., with a yield strength of approximately 1425 MPa), and the third structure is replaced with equal strength UHS steel bars. A numerical model of the RC frame structure was developed and then validated using previous experimental results. The exceeding probabilities at various performance limit states were calculated based on two typical engineering demand parameters (EDPs) of maximum interstory drift and residual interstory drift. The results showed that using UHS longitudinal steel bars instead of HRB 600 grade steel bars in frame columns could reduce the energy dissipation capacity of the structure, inevitably leading to an increase in the maximum interstory response of the frame. However, much lower exceedance probability was observed in the UHS‐enhanced frame under the repair available limit state based on the residual interstory drift, indicating that the UHS‐enhanced RC frame had higher seismic resilience. In addition, compared to equal area substitution, equal strength substitution is a more ideal design method that can use fewer UHS steel bars to achieve comparable reparability and a smaller increase in maximum interstory drift. [ABSTRACT FROM AUTHOR]

Energetic materials, essential for rocket propulsion, play a crucial role in aerospace systems. These materials lack sufficient safety assessments and pose significant risks to life and infrastructure. The slow progress in this field is hindered by prohibitively high experimental costs and the inherently destructive nature of these experiments. This study aimed to evaluate modeling-based safety assessments, primarily utilizing the Lee–Tarver model. It specifically addressed the threat posed by shaped charges during transportation. Experimental analyses employed 50 mm JH-2 shaped charges, targeting RDX-based JH-2 formulation, since RDX is widely used in various rocket motor propellant formulations. TNT was also used to enhance the validation of the Lee–Tarver model findings. Various logistical configurations were explored, testing steel container walls ranging from 10 mm thickness to reinforced walls of 50 mm, 60 mm, and 65 mm steel. Comparative analysis with experiments reinforced the accuracy of the Lee–Tarver model's numerical predictions. Both simulations and experiments affirmed that a 65 mm steel protection suffices for the safe transportation of RDX-based JH-2 formulations and TNT within a 10 mm storage box in logistical setups. Furthermore, this study emphasizes the Lee–Tarver model's reliability for most energetic materials safety assessments, while acknowledging certain limitations. [ABSTRACT FROM AUTHOR]

Due to the higher lateral stiffness, load-carrying, and energy dissipation capacities compared with traditional reinforced concrete (R.C.) shear walls, steel shape-reinforced concrete (SRC) shear walls, in which steel profiles are encased in the boundary elements, have been widely applied in high-rise buildings. In order to simplify the on-site construction procedure, this paper proposes a novel partially prefabricated steel shape-reinforced concrete (PPSRC) shear wall using throat connectors. Based on the pseudo-static tests of two large-scale specimens, the effect of construction methods (prefabricated or cast in place) on the cyclic behavior of PPSRC shear walls was investigated by the hysteretic loops, skeleton curves, stiffness degradation, energy dissipation, and deformation decomposition. The test results indicated that PPSRC shear walls could exhibit a comparative cyclic response with the cast-in-place SRC shear walls, and the proposed throat connectors could effectively transfer the stress of the longitudinal reinforcements. Finally, a macro-modeling of PPSRC shear walls based on the multi-layer shell elements in OpenSees 3.3.0 was established and validated by the test results, and the parametric analysis of the axial compression, steel ratio, and concrete strength of prefabricated and cast-in-place parts was then conducted. [ABSTRACT FROM AUTHOR]

To address the issue of local buckling in thin-walled steel tube concrete columns, a form of helical stiffening ribs was proposed. Axial compression tests were conducted on five sections of square steel tube concrete column specimens. The research revealed that, compared to ordinary steel tube concrete columns, the axial compression bearing capacity and deformation capacity of steel tube concrete columns with helical rib constraints increased by 18.5% and 7.7%, respectively. The helical ribs effectively enhanced the buckling resistance of the thin-walled steel tube concrete components. The failure pattern of this new type of component was characterized by diagonal cracks in the encased concrete aligning with the direction of the helical ribs, and the buckling of the steel tube walls was concentrated between the helical stiffening ribs. Based on the experiments, an analysis of the buckling performance of thin-walled steel tubes with helical rib constraints was conducted, and this was incorporated into the bearing capacity calculation. The test, simulation, and theoretical calculations showed that the bearing capacity error of the composite columns for each specimen was within 10%. Ultimately, a formula for the critical buckling bearing capacity of the helical rib steel tubes was proposed. The research findings provide a foundation for the engineering application of this new type of component. [ABSTRACT FROM AUTHOR]

This paper experimentally analyzed the behavior of steel fiberreinforced geopolymer with red mud (RM) synthetic coarse aggregates. Eight flat slabs were manufactured and subjected to symmetrical punching tests until failure. The results were compared with the estimates of the prescriptions of seven models in the literature. The results show a considerable increase in the punching shear capacity in the group with steel fiber addition; the strength gains in steel fiber-reinforced concrete were 9% and 36% for natural and synthetic aggregates, respectively, and 3% and 27% in geopolymer reinforced concrete. However, the highlight of the post-peak behavior improvement was with the geopolymer concrete, while the slabs with synthetic aggregate showed similar behavior to conventional concrete slabs. Moreover, the theoretical models showed satisfactory predictions in favor of safety and can be applied to geopolymer concrete. [ABSTRACT FROM AUTHOR]

The development of urbanization and the resulting expansion of residential and transport infrastructures pose new challenges related to ensuring comfort for city dwellers. The emission of transport vibrations and household noise reduces the quality of life in the city. To counteract this unfavorable phenomenon, vibration isolation is widely used to reduce the propagation of vibrations and noise. A proper selection of vibration isolation is necessary to ensure comfort. This selection can be made based on a deep understanding of the material parameters of the vibration isolation used. This mainly includes dynamic stiffness and damping. This article presents a comparison of the method for testing dynamic stiffness and damping using a single degree of freedom (SDOF) system and the method using image processing, which involves tracking the movement of a free-falling steel ball onto a sample of the tested material. Rubber granules, rubber granules with rubber fibers, and rebound polyurethanes were selected for testing. Strong correlations were found between the relative indentation and dynamic stiffness (at 10–60 MN/m3) and the relative rebound and damping (for 6–12%). Additionally, a very strong relationship was determined between the density and fraction of the critical damping factor/dynamic stiffness. The relative indentation and relative rebound measurement methods can be used as an alternative method to measure the dynamic stiffness and critical damping factor, respectively. [ABSTRACT FROM AUTHOR]

Structural engineers often use deep columns in high seismic areas to reduce drifts, yet this somehow contradicts what is stated in some tests in the sense that even though deep columns may satisfy current seismic provisions, they can suffer premature twisting; this is an indication that a lot of research is needed in this area. Numerical and experimental studies have been conducted to estimate the response of steel buildings with medium and deep columns under the action of static and cyclic loading; however, studies accounting for the dynamic characteristics of buildings and strong motions are not common. In addition, responses in terms of local parameters have not been considered either. In this study, the nonlinear seismic responses of steel buildings with perimeter moment-resisting frames and medium (W14) columns are numerically calculated and compared to those of similar steel buildings with equivalent deep columns in terms of cost (W27 and larger). Low-, mid-, and high-rise steel building models with different dynamic characteristics, as well as several strong motions with different frequency contents, are considered. Results indicate that the drifts of the models with medium columns may be up to 140% greater than those of the models with deep columns. Significant reductions are also observed for top displacements, normalized interstory shears, and combined normalized axial loads and bending moments. Hence, the seismic demands of the buildings with deep columns may be much smaller than those of the buildings with medium columns and, therefore, the buildings with deep columns exhibit a superior behavior, which results in more economical designs. The reduction is greater for the case of low- and mid-rise buildings than for high-rise buildings. One of the reasons for this is that as medium columns are replaced by deep columns, the stiffness and the strength increase, which are lower in the tallest model. [ABSTRACT FROM AUTHOR]

With the shortage of fossil fuels and the increasingly serious problem of environmental pollution, low-carbon industrial production technology has become an effective way to reduce industrial carbon emissions. Electrified steel plants based on electronic arc furnaces (EAF) can reduce most carbon emissions compared with traditional steel production methods, but the production steps have fixed electricity consumption behavior, and impact loads are easily generated in the production process, which has an impact on the stability of the power system. EV has the characteristics of a mobile energy storage unit. When a large number of EVs are connected to the power grid, they can be regarded as distributed energy storage units with scheduling flexibility. Through the orderly scheduling of EVs, the spatial–temporal transfer of EV charging and discharging load can be realized. Therefore, the EV situated in the steel plant's distribution network node has the capacity to be utilized by providing peak shaving and valley filling services for the steel production load. This study proposes an operation optimization scheduling method for EVs and steel plants. Taking the lowest overall operating cost as the objective, an optimal scheduling model considering EVs operation, steel plant, and distributed generator is established. Based on the IEEE-33 node distribution network model considering distributed generators, the proposed model is simulated and analyzed, and the effectiveness of the EV steel plant operation optimization scheduling strategy is investigated. [ABSTRACT FROM AUTHOR]

This work presents preliminary experimental results for advancing non-destructive testing methods for detecting steel bars in cement via contactless investigations in the X-band spectrum. This study reveals the field's penetration into cement, extracting insights into embedded bars through scattered data. Applying a quasi-quadratic inverse scattering technique to numerically simulated data yields promising results, confirming the effectiveness and reliability of the proposed approach. In this realm, using a higher frequency allows for the use of lighter equipment and smaller antennas. Identified areas for improvement include accounting for antenna behavior and establishing the undeformed target morphology and precise orientation. Transitioning from powder-based and sand specimens to real, solid, reinforced concrete structures is expected to alleviate laboratory challenges. Although accurately determining concrete properties such as its relative permittivity and conductivity is essential, it remains beyond the scope of this study. Finally, overcoming these challenges could significantly enhance non-invasive testing, improving structural health monitoring and disaster prevention. [ABSTRACT FROM AUTHOR]

The high strength, corrosion resistant, and nonmagnetic characteristics of glass fibre reinforced polymer (GFRP) bars make these bars suitable for use as reinforcement in concrete structures exposed to aggressive environments. This article presents an experimental study on the flexural behaviour of hybrid (SGFRP) concrete beams reinforced with steel and GFRP bars. Six concrete beams measuring 150 × 200 × 2200 mm were fabricated, two of which were normal reinforced concrete (RC) beams and four of which were reinforced with either a hybrid combination of steel and GFRP bars or GFRP bars only. An accelerated corrosion test using the electro-chemical corrosion method was conducted on the RC and hybrid beams until cracks appeared on the beam surface due to steel bar corrosion. Subsequently, a four-point bending test was conducted on the corroded beams until point of failure to assess the flexural behaviour of the corroded SGFRP concrete beams. The experimental results demonstrate that corroded and non-corroded SGFRP beams exhibit similar flexural behaviour and highlight the role of GFRP bars in distributing flexural cracks and in increasing beam load-bearing capacity. In addition, a simple model was proposed based on the obtained experimental results to predict the load-carrying capacities and load–deflection curves of corroded SGFRP concrete beams. [ABSTRACT FROM AUTHOR]

With the continuous acceleration of China's urbanization process, color steel plate, as a new type of building material, has been widely used in all kinds of temporary buildings and has become the spatial carrier of the specific development stage of urbanization. This study focuses on Lanzhou City as a case study to deeply analyze the spatiotemporal distribution and evolution of color steel plate buildings. Utilizing data extracted from Google imagery and GF-2 satellite images of the built-up areas in Lanzhou, spatial statistical and analytical methods such as centroid analysis, compactness index, and patch density are applied. Systematic analysis is conducted across different time periods and spatial scales to examine the evolution of indicators, including quantity, centroid distribution, spatial clustering, and distribution direction. The results show that from 2013 to 2021, the prevalence of color steel buildings in Lanzhou city initially increased and then decreased, and the number peaked in 2017, but there is a significant difference between distinct areas in the urban area. By quantitatively analyzing the spatial and temporal evolution characteristics of color steel plate buildings, this study reveals the important role it plays in promoting the urbanization process and provides a scientific basis for relevant planning decisions. [ABSTRACT FROM AUTHOR]

Non-destructive monitoring methods are crucial for the management and maintenance of assets, which include reinforced concrete (RC) structures. Steel reinforcing bar (rebar) corrosion is one of the main causes of deterioration of engineered reinforced structures as it decreases their strength and serviceability. The purpose of this study was to use nondestructive geophysical techniques to detect and monitor rebar corrosion phenomena. To achieve this, several laboratory tests were performed on RC samples partially immersed in water containing a 5% of sodium chloride (NaCl) solution. Moreover, an accelerated corrosion phenomenon was produced by supplying direct current power along the rebar. Ground-penetrating radar measurements were performed on the concrete surface using 2.0 GHz centre frequency antennas, self-potential acquisitions, and electrical resistivity tomography. Even though each technique provided specific information, a data integration approach, simultaneously using different sensors, would further improve the overall quality of the diagnosis. The data set collected was used for an integrated detection approach, effective in observing the evolution of the corrosion process along the reinforcement bar. Through these laboratory results, a multisensor approach and an integrated observation proved useful for observing the evolution of corrosion phenomenon in reinforcement bars, as a consequence of the steel rebar corrosion. [ABSTRACT FROM AUTHOR]

A spherical thin-walled stainless steel water tank without reinforced tie ribs has been designed to address the issues of easy fracture and corrosion of the ribs, difficulty in maintenance and cleaning, and short service life exposed during the use of thin-walled stainless steel water tanks with reinforced tie ribs. Firstly, an analytical model of a flat steel thin-walled water tank without reinforced tie ribs was established and subjected to static analysis under water pressure. The deformation and stress distribution patterns of the side molded plate of the flat box were obtained. Secondly, a spherical non ribbed thin-walled stainless steel water tank structure was designed with circular cross-section under different box bulge parameters, and its mechanical response characteristics under water pressure load were analyzed. A strengthening scheme was designed for the bottom box molded plate. Once again, optimize the combination design of the box scheme and the reinforcement scheme, and analyze their static, thermodynamic, and thermal solid coupling performance. Finally, the Latin Hypercube Sampling method was used to generate experimental design samples, and a response surface approximation model of a spherical thinwalled stainless steel water tank without reinforced tie ribs was constructed. The wall thickness of the box molded plate, skeleton, and reinforcement were used as design variables, and the maximum deformation and maximum equivalent stress were used as constraints. The lightweight design was carried out with the goal of minimizing mass. The research results indicate that the design program and parameter selection method for spherical thin-walled stainless steel water tanks without reinforced tie ribs proposed in the article are efficient and feasible, and can provide technical reference and theoretical support for the layout and overall optimization design of non ribbed thin-walled stainless steel water tank structures. [ABSTRACT FROM AUTHOR]

The diagrid structural system has become popular in the construction of high-rise buildings in light of significant advantages over other structural systems. The present study explores the effects of the vertical near-fault earthquake component on the axial forces of diagonal elements in steel diagrid structures. Nonlinear time-history analysis was carried out using 11 near-fault earthquake records. A total of nine three-dimensional models of 12, 18, and 24 stories, each with diagonal angles of 45, 63.4, and 71.5 degrees, were designed and analyzed. Due to the three-dimensional modeling complexities of diagrid structures, a method was developed to transform three-dimensional models into two-dimensional ones. Finally, the scenarios with and without the vertical earthquake component were compared. It was found that the incorporation of the vertical earthquake component into the analysis of diagrid structures substantially influenced the axial forces of diagonal elements. This can affect the design load estimation of diagonal elements as the main components of a diagrid structure. [ABSTRACT FROM AUTHOR]

In the paper, we present the results of an analysis of data samples of 282 damaged buildings; the samples include the age of the building, the type of vertical bearing structures, the type of construction of the external walls, the method of the insulation of the walls, the number of floors, the buildings' functions, and the extent of the damage. The primary objective of the analysis was to evaluate the possibility of using panels of cold-formed thin-walled steel profiles to repair the damaged structures. The results of a study of typical projects of large panel buildings that were constructed in Ukraine and an analysis of the practical experience of repairing these types of buildings after blast actions can also be found. The research tasks are defined for implementing this technology in the process of repairing large panel buildings. [ABSTRACT FROM AUTHOR]

The investigation of droplet impingement plays a crucial role in understanding the dynamics of fuel impact on the walls inside engine combustion chambers. To study the dynamics and heat transfer characteristics of two-component mixed droplets impacting upon an inclined stainless steel heated wall, the effect of wall tilt angle (0°–40°), Weber numbers (We, ranging from 50 to 210), and wall temperatures (Tw, between 25 and 350 °C) on the heat transfer models and spreading diameters is conducted. Through quantitative analysis of high-speed images captured during the experiments, it is observed that the spreading diameter of droplet impact on the inclined wall is closely correlated with both the wall temperature and We of the droplet. The wall tilt angle is found to modify the heat transfer state transition of the droplet to some extent. Additionally, the influence of gravity results in significant differences between the front and back spreading coefficients of the droplet. Based on the available data, a new empirical model is proposed that incorporates temperature terms and inclination to predict the maximum spreading coefficient of droplets impact on an inclined heated wall. Compared with experimental data of this study and in the literature, the maximum prediction error is less than 12.3%. [ABSTRACT FROM AUTHOR]

Underground mine structures like mine seals or built-in-place (BIP) refuge alternatives (RA) are exposed to specific loadings like explosions because of overlying and underlying strata conditions. Previous studies worked on the vertical loading response of structures like abutments from panel extraction but not the explosion resistance upon being subjected to these vertical strata loads. In this study, two steel-reinforced concrete wall designs as seal and RA applications are simulated to examine the performance and failure analysis under abutment-loading conditions during an explosion for a coal mine model using dynamic analysis by a distinct element code (3DEC). The available abutment monitoring data by longwall stoppings was used to estimate the abutment-loading conditions. The model setup was calibrated through two validation stages: (1) the concrete wall simulation with the explosion test of steel-reinforced concrete mine seal conducted by previous researchers; and (2) the stress change at the strata by the tailgate convergence-abutment-load multiplier curve. The calibrated models are subjected to various dynamic loadings to simulate explosions. The findings demonstrate that, in addition to magnitude, the pressure versus time mode of loading significantly influences the wall response. Instantaneous loading criteria can provide more cautious measurements to assess how well such walls operate in similar situations. Except for a few cases, the deformations after a single explosion are more pronounced for the effects of subsequent second and third explosions. As a result, the changes in deformation during subsequent explosions are relatively minor compared with the initial permanent deflections. [ABSTRACT FROM AUTHOR]

Several studies have been carried out to assess the building's seismic vulnerability, to mitigate the seismic risk in urban areas, which is one of the most devastating natural hazards causing considerable economic and human losses. These studies must be incorporated to improve the planning of urban areas to have resistant and resilient cities in case of disasters. The seismic feedback has shown that the build-back-better concept has a direct impact on the city's economic growth. In this paper, the existing buildings' resilience is assessed, in order to highlight the capacity of these last to keep the functionality when an earthquake occurs. This building's resilience has been determined for three types of structures: masonry, reinforced concrete and steel, according to the reconstruction time, the reconstruction cost and the damage state. This last has been assessed from empirical fragility curves developed using the log normal distribution for five structures typologies (Unreinforced masonry; reinforced masonry; RC frame; RC shear walls/Mixed RC frame-RC shear walls and steel structures). A seismic resilience scenario was performed using a geographic information system (GIS) and applied for the Blida city (Algeria) classified as a high seismic zone according to Algerian seismic regulations. According to the results found, the old districts of the Blida city, built mainly during the so-called pre-code period, will not be resilient in case of disaster. The other districts built later in the low-code and high-code periods will have, respectively, medium and good functionality. [ABSTRACT FROM AUTHOR]

A deep understanding of the particle–wall collision (PWC) behaviors of non-spherical particles is important for managing gas–solid flows in industrial applications. It is important to identify the dominant parameters and to develop the common PWC prediction models for typical non-spherical particles. In this paper, different types of non-spherical particles were used to conduct the fundamental experiments. The effects of key parameters such as particle size, non-sphericity, wall roughness, and impact angle were analyzed. The results show that the trends of the collision coefficients with the impact angle for all non-spherical particles are similar. The dominant factors of particle–wall collisions are particle sphericity and wall roughness. A model with four parameters was fitted from the experimental data. The model can predict the collisions of non-spherical particles on rough steel walls with sizes ranging from 50 to 550 microns. [ABSTRACT FROM AUTHOR]

The assessment of concrete structure durability in chlorine environments is significantly impacted by the uncertainty inherent in existing durability models. It introduces an integrated approach for updating these models based on the detection information of existing structures. This approach narrows the gap between theoretical predictions and observed structural durability. Specifically, we refined the probability model of critical chloride content by analyzing steel bar corrosion sample proportions using Bayesian theory for greater accuracy. The enhanced model enables more reliable life expectancy prediction, forming a solid foundation for maintaining and strengthening existing structures. This method was demonstrated through a case study of a reinforced concrete industrial building with a service life of 12 years. [ABSTRACT FROM AUTHOR]