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Ultra-high-performance-concrete (UHPC) possesses favorable mechanical properties and economy efficiencies and has the potential to be used as the main material to construct tower structures of offshore wind turbines (OWTs). Then the shortages of widely used pure steel OWT towers such as relatively small lateral stiffness, weak fatigue behavior and corrosion resistance can be avoided. In this work, a new type of hybrid tower structure combining a prestressed UHPC tube at the bottom and an upper steel tube is proposed to support a large-size 15 MW OWT. Detailed and carefully refined finite element (FE) analysis by ABAQUS was conducted to explore the dynamic performance of the proposed hybrid tower. The modal properties, dynamic responses, ultimate strength, fatigue strength, and economy performance of the hybrid tower were comprehensively evaluated. It shows that with a similar lateral stiffness but greatly reduced material and maintenance costs compared to a reference steel tower, the hybrid tower has enough ultimate and fatigue strength to resist huge environmental loads caused by extreme winds, waves and earthquakes. • Conceptual design of a prestressed precast UHPC-steel hybrid OWT tower. • Dynamic finite element analysis considering wind, wave and earthquake loading. • Ultimate and fatigue strength analysis to check the hybrid tower's safety. • Cost analysis proving the economic efficiency of the proposed design. [ABSTRACT FROM AUTHOR]

Despite the outstanding mechanical properties, SFRC is still underutilized in the load-bearing structures, mainly being restrained to the non-structural applications. This paper primarily investigates the effect of the innovative combination of steel fibers and the post-tensioning on the performance of concrete slabs and assesses the feasibility of using steel fiber as substitute for the conventional reinforcement in post-tensioned slabs. Building on the experimental work done by Virginia Polytechnic Institute and State University, numerical and theoretical analyses were employed to verify and extend the experimental findings. In the paper, two different reinforcement solutions (steel fibers or conventional reinforcement) were used in the slabs, and they were combined with four different tendon layouts. Among them, the banded-banded tendon coupled with steel fibers significantly enhanced the punching shear resistance of the slabs. To deepen the understanding of SFRC's viability as a structural material, the flexural strength of the slabs obtained from nonlinear finite element analysis (NLFEA) is compared against the theoretical results of design methods outlined in fib Model Code 2010 (MC2010), new FprEC2:2022 (prEN 1992–1-1:2022(E)), IAPMO UES ER-465 (IAPMO 465), and Norwegian NB 38 (NB 38). The results indicates that some of the certain provisions in the American and European Codes might be simplified, for instance: 1) steel fibers might be used as the only reinforcement to replace the minimum required bar reinforcement in post-tensioned slabs, and 2) combination of steel fibers and banded tendon layout, which could further simplify the construction process, might be applied in the engineering construction. • Numerical study was conducted to investigate the structural behavior of post-tensioned fiber reinforced slabs at SLS and ULS. • Models used to describe the behavior of SFRC in different standards are discussed. • Influence of tendon layouts and reinforcement solutions on the capacity and stiffness of post-tensioned slab was studied. • Results show that some restrictions in the current American and European Codes, ACI 318 and EC2, might not be necessary. [ABSTRACT FROM AUTHOR]

This study introduces a novel Finite Element (FE) modelling approach for accurately simulating the behaviour of Steel Concrete Filled Tubes (CFTs) subjected to both monotonic and cyclic loads. It comprehensively addresses the challenges of modelling low cyclic fatigue in steel and concrete crushing, a critical aspect often overlooked in previous studies. The methodology is rigorously validated against eight experimental tests on circular CFTs, where it exhibits remarkable precision in capturing the complex interaction between steel and concrete under various loading conditions. The prosed modelling is able to accurately catch the degradation, the number of cycles leading to fracture and the failure modes. • Finite Element simulation of CFT specimens under cyclic bending loads. • Development and calibration of a FE model for cyclic tests. • Accurate data analysis and calibration for load-displacement curves. • Novel insights into CFT mechanical behaviour simulation. • Basis for optimized design of CFT [ABSTRACT FROM AUTHOR]

This study presents the Quick-Connector, a new self-fastening joint system designed specifically for modular steel construction. By eliminating the need for a dedicated workspace during the connection process, the Quick-Connector minimizes disruptions to finishing work. A comprehensive set of tests, including pull-out, shear, and cyclic tests, was conducted on a full-scale prototype to evaluate its structural performance. The experimental results demonstrate that the Quick-Connector exhibits exceptional connecting performance, meeting the shear and tensile strength requirements for high-tension bolts. The seismic performance of the Quick-Connector was also evaluated through cyclic testing, highlighting its potential as a viable replacement for high-tensile bolts. Furthermore, a push-over analysis was carried out to develop an elastic structural design model specifically for buildings incorporating the Quick-Connector. The analysis results closely aligned with the experimental findings, validating the accuracy of the proposed model. Overall, the Quick-Connector offers a promising alternative to traditional bolted connections in modular construction, with the potential to enhance construction efficiency, quality, and safety. • Novel self-fastening joint system, Quick-Connector, for modular steel construction. • Elimination of separate working areas during connection process, enhancing construction efficiency. • Connecting performance evaluations of the Quick-Connectors indicate that they can replace high-strength bolts. • Validated push-over analysis model using MIDAS Gen for elastic structural design. [ABSTRACT FROM AUTHOR]

• Failure sequence and load sharing for standing seam metal roofs examined. • Load redistribution occurs at high wind loads with significant deformations. • Significant load is transferred to eaves and gable ridge edges under high wind. • Global buckling was observed prior to connection failures of clips. In this paper, the failure sequence and load sharing for standing seam metal roofs (SSMR), up to the limit state, were investigated using full-scale experiments. The tested SSMR system had full-scale dimensions and boundary conditions, which provided the opportunity to investigate the performance of SSMR systems under realistic conditions. The results show that there is a linear relationship between the wind pressure and clip reaction under low wind pressure (less than 500 Pa). Load redistribution happens along with the deformation of roof panels with greater load transfer to the ridge and eaves of the roof at higher pressure. Near the corner of the roof, between 27 and 46 % of the applied load is transferred to edges of the eaves and gable end. Away from the roof corner, between 17 and 23 % of the applied load is transferred to eave edge. Global buckling of panels occurs before connection failures and the initial location of global buckling is near the seam and in the middle of two adjacent clips. Two failure modes for the connections, clip slippage and fastener failure, were observed during the tests. However, the failure modes vary with the clip arrangement and boundary conditions. [ABSTRACT FROM AUTHOR]

Highlights • The performance of a mass-timber building under tornado-like vortex is assessed. • A 34 m tall mass-timber building is structurally designed using wind tunnel test data. • Straight-line and tornadic wind loads are obtained from experimental tests. • Dynamic structural analyses are carried out in time domain. • The vulnerability of drift sensitive components of mass-timber building is estimated. Abstract Tall mass-timber buildings utilize engineered wood panels to form their main gravity and lateral load resisting systems, which makes them lighter and more flexible than buildings made from concrete, masonry or even steel. In general, drift sensitive components of tall mass-timber buildings could be susceptible to damages due to increased deflection when subjected to extreme wind storms like violent tornadoes. This paper assessed the structural performance of a multi-story mass-timber building, which was designed using the customary 1-in-50 years design wind speed of the 2010 National Building Code of Canada with a load factor of 1.4, under experimentally simulated tornado-like wind fields. In the study, wind loads were obtained from laboratory simulations of tornado-like wind field and atmospheric boundary layer flow at Western University, Canada. Tornadic wind loads from the laboratory tests were scaled to five Enhanced Fujita wind speeds, representing various levels of damage. Dynamic structural analyses were carried out in time-domain to include the possible amplification due to the dynamic component of the excitation and assess floor level inter-story drift and shear force demands for various parameters. The varied parameters were tornado intensity level, the orientation of the building (aerodynamic direction), and critical damping ratio. Based on the obtained results, the vulnerability of drift sensitive components of the study building under tornado-like wind field was estimated. It is shown that strong tornadoes may pose significant damage to drift sensitive non-structural components of multi-story mass-timber buildings. Finally, roadmaps to improve the design of mass-timber buildings in tornado-prone areas are forwarded. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Review of approaches for integration of seismic loss estimation and life cycle assessment. • Life cycle repair impacts are best considered using time-based loss assessment. • Identification and comparison of Economic Input-Output and process-based LCA data. • Non-structural components often account for more impacts than structural components. • Probabilistic presentation of results and reconsideration of building lifetime is needed. Abstract Interest in sustainability and resilience of buildings has led to a growing body of literature on merging environmental impact assessment methods with seismic loss estimation methods. Researchers have taken different approaches to connecting the two fields with the common goal of estimating the social, environmental, and economic impacts of damage to buildings subject to seismic events and thus enabling the study of tradeoffs between performance objectives. The differences among these studies include topics such as treatment of uncertainty, types of components and systems considered in the performance assessment, fidelity of structural analysis ranging from region-specific empirical fragility curves to detailed building-specific finite element analysis, scope of life cycle assessment, and so on. One of the aspects of the most diverse treatment has been in obtaining environmental impact data and relating it to pre-use impact estimates. For example, the translation of damage and repairs into life-cycle environmental impacts has been done by one of three approaches: (1) Economic Input-Output Life Cycle Assessment (EIO-LCA) has been applied to economic loss estimates; (2) repair cost-ratios have been applied to environmental impacts from the pre-use stage; and (3) repair descriptions have been used to model environmental impacts of damage scenarios directly using process life cycle assessment (LCA). All of the approaches are generally accepted but may pose limitations in certain applications and can potentially result in inconsistent conclusions from study to study. A review of existing literature in the area is presented and is followed by a comparative analysis and discussion of the outcomes of taking different environmental life cycle assessment approaches. This paper provides a comprehensive overview of the research efforts in this area and discusses opportunities for further development in order to make the implementation consistent and practical for design decision making. [ABSTRACT FROM AUTHOR]

The aim of the study consists of evaluating the seismic robustness of a three-dimensional (3D) reinforced concrete (r.c.) structure equipped with single-concave friction pendulum system (FPS) devices by estimating the seismic reliability in its design life (50 years) of different models related to different malfunction scenarios of the seismic isolators. Among the uncertainties, the elastic response pseudo-acceleration corresponding to the isolated period is assumed as the relevant random variable and, by means of the Latin Hypercube Sampling technique, the input data have been defined in order to develop 3D inelastic time-history analyses. In this way, bivariate structural performance curves at each level of the r.c. structural system as well as seismic reliability-based design abacuses for the FP devices have been computed and compared to evaluate the robustness of the r.c. system considering different models related to the different failure scenarios analysed. Contextually, the seismic robustness of the abovementioned r.c. structural system has also been examined by considering both a configuration equipped with beams connecting the substructure columns and a configuration without these connecting beams in order to demonstrate their effectiveness in improving the seismic robustness in the scenario of a malfunction of a seismic device and provide very useful design recommendations for base-isolated structures equipped with FPS. [ABSTRACT FROM AUTHOR]

The aim of the study consists in evaluating the life-cycle costs of a r.c. 3D system isolated by single-concave FPS bearings with different isolated periods in order to evaluate the potential benefits provided by increasing values of the isolation degree. In particular, assuming the elastic response pseudo-acceleration related to each isolated period and the coefficient of friction as random variables relevant to the problem characterized by appropriate probability density functions, the Latin Hypercube Sampling method has been adopted as random sampling technique in order to define the input data and perform 3D non-linear dynamic analyses. Thus, bivariate structural performance curves for each story of the superstructure and for the substructure as well as seismic reliability-based design (SRBD) abacuses for the isolation level have been defined for the different values of the isolation degree. Finally, the life-cycle cost analysis of the isolated system with different curvature radius of the FP bearings has been accomplished taking into account both the initial costs and the expected loss costs, due to future earthquakes, of the overall system during its design life (50 years) in order to evaluate the influence of the isolation degree on both the seismic performance and the total costs. [ABSTRACT FROM AUTHOR]

The friction pendulum system (FPS) is becoming a widely used technique for seismic protection and retrofit of buildings, bridges and industrial structures due to its remarkable features such as the stability of physical properties and durability respect to the elastomeric bearings. Experimental data also showed that the coefficient of friction depends on several effects (i.e., sliding velocity, apparent pressure, air temperature, cycling effect) so that it can be assumed as a random variable. The aim of the study consists in evaluating the seismic reliability of a base-isolated structure with FP isolators considering both isolator properties (i.e., coefficient of friction) and earthquake main characteristics as random variables. Assuming appropriate density probability functions for each random variable and adopting the Latin Hypercube Sampling (LHS) method for random sampling, the input data set has been defined. Several 3D non-linear dynamic analyses have been performed considering both the vertical and horizontal components of each seismic excitation in order to evaluate the system response. In particular, monovariate and multivariate (joint) probability density and cumulative distribution functions have been computed and, considering the limit state thresholds and domains (performance objectives) defined respectively on mono/bi-directional displacements, assumed as earthquake damage parameter (EDP) according to performance-based seismic design, the exceeding probabilities (structural performances) have been evaluated. Estimating the reliability of the superstructure, substructure and isolation level led to define and propose reliability-based abacus and equations useful to design the FP system. [ABSTRACT FROM AUTHOR]

• Research studies on mechanical characteristics of aluminium alloys in and after fire are reviewed. • Structural fire behaviour of members, connections, joints and overall systems is discussed. • Passive and active fire protection measures for aluminium alloy structures are presented. • An outlook for the future research in this field is presented. Aluminium alloys are gaining increasing use in the construction industry, underpinned by extensive research and the growing availability of codified structural design rules at room temperature. More recently, considering that the material properties of aluminium alloys degrade significantly at elevated temperatures, a substantial number of studies have also been conducted to investigate the behaviour and design of aluminium alloy structures exposed to fire. This paper presents a review of recent studies on the mechanical characteristics of aluminium alloys in fire and after fire, as well as the structural behaviour of aluminium alloy structures in fire conditions, considering members, connections, joints and overall systems. In addition, possible passive and active fire protection measures for aluminium alloy structures are introduced and discussed. Lastly, recommendations for future work on the structural fire behaviour of aluminium alloy structures are set out, providing insight into aspects that require further investigations to promote the more widespread use of aluminium alloys in structural applications. [ABSTRACT FROM AUTHOR]

This paper presents an experimental investigation on the structural performance of Dou-Gong brackets of Yingxian Wood Pagoda under vertical load. Two scaled models of typical Dou-Gong brackets of the pagoda were designed, manufactured and tested. Both models behaved similarly to that of a wood component under compression perpendicular to grain. Four failure modes of the components were identified, these included yield of component under compression perpendicular to grain, fracture of component under tension perpendicular to grain, fracture of component due to shear and breaking-off of component under bending. The structural performance of the model Dou-Gong brackets was revealed from test observations, and the initial stiffness and the load-carrying capacity of the prototype Dou-Gong brackets of the pagoda were derived based on the similitude theory. This study provides reference, from a structural point of view, for the preservation of cultural heritage structures such as Yingxian Wood Pagoda. [ABSTRACT FROM AUTHOR]

Highlights: [•] Design details affected failure mode. [•] Welding method and design detail did not affect initial stiffness and yield strength. [•] Partial penetration welding at the V-point would cause brittle fracture. [•] Web-continuous type is stronger and more ductile. [Copyright &y& Elsevier]

• Buckling of elliptic cylinders with varied slenderness and eccentricity is studied. • Fast performance overviews are attained for FRP components through shell analyses. • Lamination parameters are used to express the stiffness properties in compact form. • The utilized methods provide design bases for optimizing FRP structural components. Structural members made of fiber-reinforced polymers (FRP) attract increasing attention in the development of novel architectural systems that challenge the standard design methodologies. Cylindrical surfaces constitute one of the typical geometric sets obtained with the FRP component fabrication. This paper explores the influences of two geometric parameters on the buckling performance of elliptical cylinders: inverse slenderness (ratio of minimum diameter to height) and eccentricity (ratio of radii along semi-axes). The overall stiffness properties are defined using lamination parameters. This analysis method eliminates the dependency of optimal solutions on the initial assumptions regarding the laminate configuration, which needs to be explicitly described in multi-layer modeling. Finite element analyses are utilized to compute buckling loads of the cylinders under axial compression force and bi-axial bending moments. The optimal lamination parameters and buckling stresses are determined for various parameters, and the lamination parameters corresponding to the optimal and simple [±45°] angle-ply design points are presented in the lamination parameter plane via Miki's diagram. The results reveal the level of performance that can be achieved by a specific geometry and provide guidelines for the optimal design of elliptical laminated cylinders against buckling. [ABSTRACT FROM AUTHOR]

• New pre-fabricated lightweight slab system (PreSlabTec) of high structural performance. • PreSlabTec demonstrated a very high load carrying capacity and ductility performance under flexural loading configurations. • The PreSlabTec never failed in shear, despite the very exigent shear loading configurations adopted. • For the standard design requirement for slabs of residential buildings, a relatively low average creep coefficient of 0.13 was obtained. • The developed theoretical approach for the design of PreSlabTec has presented very good predictive performance. This paper presents a new pre-fabricated lightweight slab system where the relatively high post-cracking tensile capacity of steel fibre reinforced concrete (SFRC) is combined with the high ductility and tensile strength of optimized shape profiles made by cold formed steel sheets for a synergetic result in terms of structural performance. The SFRC fills the longitudinal steel profiles (girders) that have openings in the web for materializing SFRC shear mechanisms that provide very high shear resistance to the slab. This slab system (designated by PreSlabTec) includes a SFRC deck of 40 mm thickness and lightweight blocks serving as permanent moulds to the SFRC and thermal insulation. The transversal stiffness is assured by thin wall tubular steel profiles that remained anchored in the girders due to their openings. PreSlabTec is simple and fast of executing and was conceived for being produced in an automation process of prefabrication industry. For assessing the performance of the PreSlabTec in serviceability and ultimate limit state conditions, an extensive program with almost real scale prototypes was executed and tested under loading configurations for flexural and shear failures. For the flexural loading configurations, the PreSlabTec demonstrated a very high load carrying capacity and ductility performance. The PreSlabTec never failed in shear, despite the very exigent shear loading configurations adopted. The long-term deflection was also experimentally evaluated for the standard design requirement for slabs of residential buildings, and a relatively low average creep coefficient of 0.13 was obtained. Finally, the theoretical approach for the design of PreSlabTec is described and its good predictive performance is demonstrated. [ABSTRACT FROM AUTHOR]

Abstract: In this paper the authors summarize the results of a study devoted to evaluate, using nonlinear dynamic analyses, the seismic behavior of six reinforced concrete moment resisting chevron braced framed buildings (RC-MRCBFs). Buildings are regular and were designed using a proposed capacity design methodology adapted to the seismic, reinforced concrete and steel guidelines of current Mexico’s Federal District Code (MFDC-04) and the Manual of Civil Structures (MOC-2008). RC-MRCBFs were assumed to be located in three different soil conditions in Mexico and were designed for a specific shear strength ratio between the bracing system and the moment frame system according to the recommendations available in MFDC and proposed in previous studies. Two-dimensional models that account for the interaction among frames were used for the nonlinear dynamic analyses of the capacity-designed buildings using RUAUMOKO software. Several artificial records corresponding to the maximum credible earthquake associated to the design spectra were used to carry out the nonlinear dynamic analysis. From the results obtained, it is possible to conclude that if capacity design principles and specific design parameters for the new design of RC-MRCBFs are used, suitable global ductility capacities and overstrength demands are obtained, and a satisfactory structural performance is achieved. [Copyright &y& Elsevier]

Abstract: The structural performance and cracking behavior of corroded reinforced concrete beams made with self-consolidating concrete (SCC) were investigated and compared to those of normal concrete (NC) beams. Six reinforced concrete beams without web reinforcement (400 mm wide × 363 mm deep × 2340 mm long), designed to fail in shear, were tested after being subjected to accelerated corrosion. The beams were partially immersed in sodium chloride solution, then subjected to an impressed current until they reached three levels of corrosion (0%, 10%, and 30% theoretical mass loss). They were then tested under mid-span concentrated load until failure. The performance of the corroded SCC/NC beams was evaluated based on the results of crack patterns, crack widths, loads at first flexure and first diagonal cracks, mid-span deflection, ultimate load, and failure modes. In addition, the resulting crack widths and mid-span deflections were compared with the predictions of several major code-based equations. The results showed that at severe corrosion level, the failure mode for the SCC beam had changed from shear failure to anchorage slipping failure. This result was attributed to the increase of the corrosion concentration at the far end corners of the SCC beam, located far away from the casting point, due to poor quality concrete resulting from insufficient compaction. For designers considering SCC for structural applications, the recommendations in this paper may be particularly useful. [Copyright &y& Elsevier]

• A replaceable monolithic-like precast concrete column-foundation connection is proposed. • Four full-scale specimens are tested under constant axial and lateral cyclic loading. • Experimental results are used to assess a wide range of seismic performance parameters. • Precast connections exhibit very similar performance as their monolithic counterparts. • Experimentally validated FE models are developed for design and assessment purposes. Precast structures are increasingly used in modern construction since they offer advantages such as cost-efficiency, better material quality, and fast construction due to their mass production compared to cast-in-situ structures. However, development of monolithic-like precast connections to ensure adequate seismic performance is still a challenging task. This study aims to introduce a monolithic-like column-foundation precast connection, which is easy to assemble and disassemble and therefore is replaceable in case of excessive damage. To investigate the efficiency of the proposed system, four full-scale precast and monolithic column-foundation connection specimens are tested under constant axial load and lateral reversed cyclic loading. Experimental results are then used to obtain seismic performance parameters such as failure mode, flexural capacity, initial stiffness, ductility, energy dissipation and curvature distribution. The results indicate that, in general, the proposed precast connections exhibit similar structural performance as their monolithic counterparts. Subsequently, experimentally validated finite element (FE) models are developed to provide practical tools for seismic design and performance assessment of the proposed precast connection system. It is shown that the developed models can accurately estimate the load-bearing capacity, initial stiffness and post-peak behaviour of both precast and monolithic column-foundation connections. [ABSTRACT FROM AUTHOR]

• Energy-based methodology in seismic resistant design for RC frames is proposed. • Proposed energy-balance method is coupled with performance-based seismic design. • Constant amplitude fatigue is used in energy dissipation capacities of RC members. • Energy demand distribution in RC frame is done by nonlinear static pushover analysis. • Numerical examples include code-compliant design and soft-story frames. The force- and displacement-based design methodologies have been widely used in current seismic design practice. In both methodologies, inelastic behavior is determined indirectly since the seismic demands are derived from elastic acceleration response spectra. In this study, a novel energy-based design (EBD) approach is proposed in the determination of both seismic demand and dissipation capacities of reinforced concrete (RC) frame members through their inelastic behavior directly. In the case of frame-type RC structures, the distribution of demand plastic energy throughout the structure is achieved. The proposed EBD is then accomplished by comparing the demand plastic energy with the energy dissipation capacity of members while integrating performance-based design guidelines. A cantilever column and a benchmark frame, both from the literature, are analyzed in verification of the proposed methodology. Comparisons are made between force, displacement and EBD methodologies in terms of soil condition, member, system and ductility performance requirements. Member and global performance targets are found to be comparable in displacement and EBD methodologies. However, owing to lack of ductility considerations in the prior design methodologies, the proposed EBD showed more reliable result in the determination of both cross-sectional geometry and its rebar configuration. The proposed methodology provides better understanding of damage state limits of RC members by incorporating the plastic energy spectrum, which includes cyclic action, duration, and frequency content of ground motions, as well as inherent ductility in both demand and capacity determinations. The sensitivity analyses between code compliant-design and soft-story-mechanism buildings showed a distinct difference in the variations of seismic energy among the members and their corresponding damage distributions. EBD methodology provides better in depth understanding of the seismic design in terms of demand and capacity of member and overall structural system, and their corresponding performance. [ABSTRACT FROM AUTHOR]

• The structural and charring behavior of wood under real fire exposure is characterized. • Current fire design codes underestimate the charring rate of wood under fire exposure. • Service load accelerates charring of wood structural elements under fire. • The mechanism behind the service loading on the thermomechanical behavior of wood is proposed. Wood has been widely used in construction and infrastructures due to its great environmental and economic benefits. However, wood structures are highly vulnerable to fire because of its flammability. The effect of unavoidable service load on the structural performance and charring characteristics of wood structures is still unclear, posing serious safety risk under fire hazard. In this study, the fire behavior of wood components under different service loads was experimentally evaluated. To assess the fire performance in detail, the structural response and charring characteristics, including charring depth and charring rate were provided and compared. The results highlight that service load can accelerate the charring rate and increase the charring depth, aggravating the thermal degradation of wood element under fire exposure. An influential mechanism of service loading condition on the fire behavior of wood is proposed and a more accurate approach to predict charring rate is recommended. The findings from this study can advance the understanding on structural behavior of wood under fire and contribute to the trustworthy charring predictions as well as to reliable fire design of wood structures. [ABSTRACT FROM AUTHOR]

• The characteristic-response changes of roof system during failure process are recorded by measuring instruments. • The failure process of roof system is divided into three stages according to the change in interaction among components. • The three-stage failure process is verified in combination with the changes in characteristic-response. • Explain the damage in the experiment according to the deformation map of roof system. • Analyze the relationship between failure stage and performance of roof system, so as to serve PBD. Compared with the current popular performance-based design (PBD) method, the current research of scholars on structural performance as a PBD foundation is insufficient. By considering the failure process of a standing seam roof system as an example, the wind-resistant performance of a roof system is evaluated by studying the wind uplift failure mechanism. The deformation process of roof-system components is obtained using numerical simulations. The analysis shows that the interaction between the vertical plate and anti-wind clip occurs in three stages: from non-contact and no interaction to anti-wind clips restraint vertical plate deformation, and finally to vertical plates drive anti-wind clip rotation. The changes in the structural responses (seam displacement and contact stress) and damage during the failure process of the roof system are obtained through experiments. Analysis of the variation in the curve of the structural responses with the load shows that the increase in the structural responses also occurs in three stages. Combined with the damage sequence, the aforementioned three failure stages are found to correspond to three different damage stages. In the first stage, the roof system is in an elastic stage. Second, the roof system is in the yield stage, and curling undergoes partial separation, which results in an interspace that is adverse to roof waterproofing. In the third stage, permanent plastic deformation occurs in the roof system, which leads to roof ponding. It was observed that the three-stage failure process represents different performance levels of the roof system, and some results from this study can be used as a guide for the definition of roof-system performance level in the future. [ABSTRACT FROM AUTHOR]

• Corrosion resistance of SCC and LWSCC beams covered or wrapped with ECC. • Corrosion performance based on current flow, half-cell potential and rebar mass loss. • Shear resistance, ductility and energy absorption capacity of corroded ECC wrapped beams. • Comparative post-corrosion structural performance of SCC and LWSCC beams. • Comparative structural performance of un-corroded and corroded beams. In this study, effect of Engineered Cementitious Composite (ECC) covering and wrapping on corrosion resistance and structural performance of un-corroded and corroded shear beams made of self-consolidating concrete (SCC) and light weight SCC (LWSCC) has been extensively investigated. An accelerated corrosion test on beams has been performed to reach the required high degrees of corrosion (30–40% of rebar mass loss). Both corrosion and structural performance of corroded beams has been assessed and analysed. The structural performance of un-corroded and corroded beams has also been compared. The corrosion performance has been evaluated in terms of current flow, half cell potential, actual rebar mass loss, reduction in diameter etc. The structural performance has been assessed and compared in terms of load–deflection behaviour, 1st flexure/diagonal cracking load, ultimate failure load, post cracking shear resistance, ductility and energy absorption capacity, failure load and failure modes. Composite beams with ECC covering exhibited superior corrosion resistance and post-corrosion structural performance as compared to full depth SCC or LWSCC counterparts. The performance of ECC wrapped composite beams has been found to be better than those with covering. Overall, ECC can be used as covering or wrapping in conventional SCC/LWSCC beams to enhance their corrosion resistance performance significantly. [ABSTRACT FROM AUTHOR]