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This paper discusses the challenges in using natural fibers for the development of textile-reinforced mortar (TRM) composites with pseudo-strain-hardening and multiple cracking behavior. The particular characteristics of natural vegetal fibers are analyzed with reference to data from the literature. It is concluded that the efficient use of these fibers as composite reinforcement requires the development of treatment or impregnation protocols for overcoming durability issues, eliminating crimping effects in tensile response and imparting dimensional stability. Relevant experimental research on the synthesis and performance of natural TRMs is reviewed, showing that the fabrication of such systems is, at present, largely based on empirical rather than engineering design. In order to set a framework regarding the properties that the constituents of natural TRM must meet, a comparative analysis is performed against inorganic matrix composites comprising synthetic, mineral and metallic reinforcement. This highlights the need for selecting matrix materials compatible with natural fibers in terms of stiffness and strength. Furthermore, a rational methodology for the theoretical design of natural TRM composites is proposed. First-order analysis tools based on rule-of-mixtures and fracture mechanics concepts are considered. Based on the findings of this study, paths for future research are discussed. [ABSTRACT FROM AUTHOR]

Natural fibre composites present a very appealing area of research for the structural strengthening of masonry structures. Natural fibres possess several drawbacks, such as low initial stiffness and poor interfacial bond behaviour with inorganic matrices that hinder their functions. Such challenges were overcome by applying an innovative nanocomposite-based impregnation system that was pre-engineered and presented by the authors previously. In this paper, a full experimental study involving pullout, tensile tests and large-scale testing via diagonal compression test was carried out to evaluate the structural efficiency of the developed system. Remarkable improvement at yarn-to-matrix level upon nanocomposite coating was observed. At a medium bond length, yarn rupture was observed, highlighting the great anchorage provided by the nanocomposite coating within the matrix. Coupons cast with the developed system demonstrated outstanding composite behaviour and multicracking under tensile loading. Finally, wallets strengthened with the developed system displayed multiple cracks and maintained high shear capacity (40–60 % of τmax) at remarkably large displacements developed at later stages of the test. Such ductility is crucial for retrofitting masonry structures, especially in seismic areas. • Remarkable improvement at yarn-to matrix level upon nanocomposites coating. • Nanocomposite coating increased pullout load by 525 % for 30 mm, 420 % for 50 mm, and 425 % for 70 mm bond lengths. • Remarkable composite behaviour and strain hardening were attained by nanocomposite-coated textiles. • NTRM-strengthened wallets maintained high shear capacity at remarkably large displacements developed at later stages. [ABSTRACT FROM AUTHOR]

• Seismic performance of the rammed earth components is numerically investigated. • A novel advanced simulation procedure for further applications is introduced. • Possible failure modes of the rammed earth walls under earthquakes are highlighted. • Strengthening by LC-TRM as a compatible and affordable solution is investigated. • Knowledge gaps in seismic performance of rammed earth components are addressed. The importance of raw earth is highlighted by the millions of persons living in earthen buildings around the World and by numerous historical monuments made of this material. Its widely availability led to the development of a variety of building techniques, including rammed earth, which is the main focus of this study. Similarly to unreinforced masonry structures, rammed earth buildings acceptably withstand gravity loads, but are significantly vulnerable to earthquakes. In this regard, great attention has been put on the proposal of efficient, compatible, affordable and reversible strengthening solutions. However, very limited studies address either the experimental testing or modeling of the seismic response of such buildings. The current study investigates the seismic out-of-plane performance of a plain and subsequently strengthened rammed earth subassembly (U-shape) using an advanced finite element modeling approach calibrated based on previously conducted small-scale experiments. Here, failure mechanisms, corresponding capacity and efficiency of the adopted strengthening solution (low-cost textile-reinforced mortar) are evaluated by means of pushover analyses. Then, the reliability of the pushover analyses is assessed by comparing its outcomes with that of the incremental dynamic analyses. In general, the failure was found to be governed by overturning of the web wall due to its detachment from the wing walls, while the strengthening was found to increase the capacity and delay the damage development. [ABSTRACT FROM AUTHOR]

• Poor structural connections in historical buildings can lead to dangerousmechanisms and need reinforcement; • Bilinear models of connections can be adopted for nonlinear local andglobal analysis of existing masonry buildings; • Advanced hysteretic connections calibrated upon experimental data canbe considered within FEM approach; • Local analysis based on virtual work principle can give an overview of thevulnerability of Out Of Plane walls with poor connections; • The assumption of absent or perfect connecitons may lead to a wrongestimation of the global strength capacity. Out of plane mechanisms in historical earthquake-prone buildings are frequently due to weak wall-to-wall and wall-to-horizontal diaphragm connections solely designed for gravitational loads and generally neglected in the seismic analysis of unreinforced masonry buildings. Accurate modeling of structural connections is generally hard and nonlinear behavior can only be estimated when experimental data are available. This paper studies the influence of plain and strengthened wall-to-horizontal diaphragm connections on global and local analysis by developing and using simplified and advanced connections models calibrated upon experimental cyclic curves. The beneficial effects of the strengthened solution under study are demonstrated by means of global nonlinear static and incremental dynamic analysis, as well as local analysis based on the virtual work principle, but also advanced stability of rigid blocks. Hysteretic numerical models, accounting for strength degradation and energy dissipation capacity, are developed on the basis of available experimental results seeking to simulate the nonlinear behaviour of wall-to-horizontal diaphragm connections. This study aims at providing an innovative procedure at the forefront of the global and local analysis of structural connections in historical constructions. The behaviour of the building modelled with nonlinear connections is in between that of the building modelled with (i) poor and (ii) perfect connections commonly adopted in favor of simplified analysis. Results reveal that simplifications may imply errors up to 70% of the overall capacity of the building. [ABSTRACT FROM AUTHOR]

Textile Reinforced Mortars (TRMs) have received extensive attention for externally bonded reinforcement of historical and masonry structures. Despite this recent attention, the available information on the test methods and mechanical performance of TRMs at different scales are limited. Extensive experimental results are still necessary for development of design formulas and application guidelines. This paper presents a multi-level experimental investigation on the performance of Steel Reinforced Grouts (SRGs) as a common TRM type. The focus is not only on the mechanical characterization but also the test methods and practical challenges. The tests include materials characterization, fiber-to-mortar bond characterization, tensile tests on TRM composite, and TRM-to-masonry bond characterization tests. The tests are performed on three different SRG systems made of pozzolanic lime-based and geopolymeric-based mortars as sustainable matrices for strengthening and restoration applications. [ABSTRACT FROM AUTHOR]

The growing concerns regarding the environmental impact generated by the use of inorganic materials in different fields of application increased the interest towards products based on materials with low environmental impact. In recent years, researchers have turned their attention towards the development of materials obtained from renewable sources, easily recoverable or biodegradable at the end of use. In the field of civil structures, a few attempts have been done to replace the most common composites (e.g. carbon and glass fibers) by materials less harmful to the environment, as natural fibers. This work presents a comprehensive experimental research on the mechanical performance of natural fibers for the strengthening of masonry constructions. Flax, hemp, jute, sisal and coir fibers have been investigated both from physical and mechanical points of view. The fibers with better performance were tested together with three different matrices (two of organic nature) in order to produce composites. These experimental results represent a useful database for understanding the potentialities of natural fibers as strengthening systems. [ABSTRACT FROM AUTHOR]

Highlights: [•] Schist constructions represent an important landmark of vernacular architecture. [•] Material and mechanical properties of schist stone were experimentally assessed. [•] Anisotropy planes have a leading role in the schist’s mechanical behaviour. [•] Strong correlations were established between physical and mechanical parameters. [ABSTRACT FROM AUTHOR]

Highlights: [•] The strength of unstabilised rammed earth built with granite residual soils is low. [•] Stabilization is required to build rammed earth with granite residual soils. [•] The alkaline activation of fly ash was tested as stabilisation technique. [•] The alkaline activation improves the strength and durability of rammed earth. [Copyright &y& Elsevier]

Abstract: The performance of the interface between FRP and masonry is one of the key factors affecting the behavior of strengthened masonry elements. Therefore, a sound understanding of the interface behavior is crucial at the design stage. In this paper, the effect of mortar joints in the bond behavior of FRP-strengthened masonry prisms is investigated through numerical modeling. The numerical simulation is performed by adopting a nonlinear three-dimensional micro-modeling approach. Different smeared crack models are considered, and the results are compared in terms of local stress and strain distributions, global force–slip response, and cracking pattern. The accuracy of the FE predictions have been assessed by comparing the results with test data and it was found that three-dimensional FE modeling combined with a rotating smeared crack approach gives the best results, both at local and global levels. Finally, the numerical results obtained considering the presence of mortar joints with different mechanical properties are presented and critically discussed. [Copyright &y& Elsevier]

Abstract: A quantitative analysis of the in-plane shear capacity of tuff masonry panels externally reinforced with FRP diagonal layout has been carried out. The objective is to provide a rational approach to the definition of the contributions from masonry and FRP to the lateral in-plane resistance of strengthened panels. Relevant experimental results of monotonic shear-compression tests are carefully analysed. A truss model approach, combined with a proper masonry strength criterion for masonry is proposed and validated. A comparison between computed and experimental data confirms the validity of the procedure in view of practical applications and code recommendations. [Copyright &y& Elsevier]

Abstract: This paper reports the results from a geometrical survey carried out on 59 segmental masonry arch bridges from Portugal and Spain, with a focus on the adjacent geographical areas of northern Portugal and north-western Spain. Historical empirical rules are briefly presented and further compared against the bridges’ geometrical data. Departing from a detailed discussion of the geometrical results, eight reference bridges were defined as representative of the sample. Subsequently, the paper deals with a parametric assessment of the load-carrying capacity of the reference bridges and a discussion of results. It was found that arch thickness and physical properties of the fill are of paramount importance in terms of ultimate load-carrying capacity. Furthermore, the results indicate that the bridges from the sample are structurally safe with respect to applicable legislation. [ABSTRACT FROM AUTHOR]

The paper presents the results of experimental research on the structural behavior of dry joint masonry. The most relevant experimental results concern the strength response of stone dry joint masonry walls subjected to in-plane combined compressive and shear loading. Significant features of the structural behavior shown by the walls are discussed and conclusions on their ultimate capacity and observed failure mechanisms are addressed. Complementarily, the application of an existing numerical model, stemming from plasticity and based on a micromodeling strategy, is also presented and discussed with regard to its capacity to simulate the obtained experimental results. The model was calibrated with data collected from complementary tests carried out on specimens and prisms made of the same type of stone. Finally, the usage of a simplified method of analysis based on a continuum of diagonal struts is also addressed. [ABSTRACT FROM AUTHOR]

With the increasing application of textile-reinforced mortars (TRMs) for the strengthening of existing masonry structures, knowing the long-term behavior of these composites is increasingly of great importance. In recent years, there has been a progressive research effort on the durability of TRM composites following different aging protocols, yet the durability of TRMs still necessitates comprehensive experimental studies for a better understanding of their behavior. On the other hand, there is also a lack of established aging methods, including acidic attack. The present study aims to leverage knowledge of the durability of TRMs when exposed to acidic attack. For this purpose, two different commercial fabrics made of glass and basalt fibers and a lime-based mortar have been used. In parallel, two aging conditions were also investigated considering 1000, 3000, and 5000 hours of exposure. Overall, a total number of 462 specimens were tested, including tests for the matrix, fabric, and composite. Compressive, flexural, and elastic modulus tests studied the variation in the mechanical properties of mortar, tensile tests focused on the textiles, and pull-out and single-lap shear tests were used for TRM composite's behavior. To investigate possible changes in material behavior due to aging, mineralogical and chemical analysis including Optical Microscopy, SEM, XRD, and TGA were carried out. • Investigating the long-term behavior of textile-reinforced mortars (TRMs), addressing the importance of their durability. • Implementation a campaign involving 462 specimens, using glass and basalt with a lime-based mortar under acidic conditions. • Investigating the effect of the acidic environment on the behavior of both the constituent's component and the composite. • implementing the standard material characterization tests, and pull-out and single lap for the TRM composites. • Microstructural investigation over the aged mortar including XRD, SEM, TGA, and optical microscopy. [ABSTRACT FROM AUTHOR]

• A low cost TRM composite is proposed to strengthen adobe vaults. • The strengthening techniques are tested by imposing increasing cyclic displacements. • The tested techniques improve the vaults' structural behavior. • The low cost TRM composite applied at the extrados improves the ultimate displacement. This paper deals with the structural behaviour and strengthening of adobe vaults representative from historical buildings of the city of Yazd, Iran. Eight destructive tests were performed on 1:3 scaled adobe vault models by loading them at 30% of the span in loading–unloading cycles of increasing vertical displacement. The models were tested considering both unstrengthened and strengthened conditions, where the strengthening consisted of an externally bonded low-cost textile reinforced mortar (LC-TRM) composed of a low-cost fiber-glass mesh embedded in earth-based mortar. Three different strengthening strategies were evaluated, namely by testing undamaged models strengthened at the extrados, undamaged models strengthened at the intrados and repaired models strengthened at the intrados. The experimental results show that the adopted LC-TRM composite improves the structural behavior of adobe vaults, by increasing substantially their load-bearing capacity and by changing the failure mechanism to more ductile ones. [ABSTRACT FROM AUTHOR]

The economic and social losses due to increasing bridges collapse over the years have underlined the importance of the development of more robust bridge structural systems when exposed to harmful events, such as natural hazards, human-made hazards and human errors. Natural and human-made hazards are usually explicitly addressed in the numerous works available in the literature, but when it comes to human errors, very few studies can be found. It is worth mentioning that human errors have been identified as one of the main causes of bridges failure. Consequently, the main goal of this paper is the assessment of human errors impact on the robustness and safety of a prestressed reinforced concrete bridge through a probabilistic-based approach. Uncertainties concerning the numerical model, material strength, geometry and loading condition are used as key input parameters for the probabilistic assessment. Considering the structural system performance in its early days (i.e., virgin reliability index) the human error impact in structural safety is measured according to the structural system performance reduction given different errors with different magnitudes. Therefore, the structural system ability to maintain acceptable levels of performance, given such errors, is assessed. [ABSTRACT FROM AUTHOR]

• The collective performance of Masonry Aggregates affects the individual units. • A novel BIM to FEM framework for Masonry Aggregates is outlined. • The Level of Information Need for solid FEA of Masonry Aggregates is defined. • An automated process from IFC to tetrahedron finite elements is developed. • The developed methods follow Open BIM logic. Masonry building aggregates are complex historical structures comprising interconnected buildings. The safety of each building depends not only on its structural integrity but also on the interactions with neighbouring structures and their collective performance. The structural assessment of such complex constructions can benefit from BIM methodology. The latter eases modelling complicated solid geometries and assigning mechanical properties information essential for developing a reliable finite element model. Thus far, BIM to finite element analysis procedures applied to historic constructions have remained laborious, semi-automatic, and based on proprietary software. This paper introduces an open-source automated solid finite element analysis method using OpenBIM data (IFC). The tool implemented automatically creates tetrahedron mesh and assigns mechanical properties, self-weights, and fixities at the structure's base. The methodology is applied to an actual masonry building aggregate to validate its capability of working with complex geometries and scalability. [ABSTRACT FROM AUTHOR]

• Granite and schist are key construction materials in vernacular heritage. • Preservation of vernacular dry stone heritage requires a scientific knowledge of the materials. • Experimental testing of representative granite and schist stones. • Effect of stone anisotropy over physical and mechanical properties. • Assessment of water saturation on stones mechanical properties. Knowing and understanding historical building materials and techniques is a fundamental step to ensure successful heritage preservation procedures. An experimental campaign was designed and implemented to acquire scientific information about the physical and mechanical behaviour of schists and granites used in Northwest Portuguese vernacular dry stone masonry. Results show schists strong anisotropy, and influence of foliation regularity, over the main physical and mechanical parameters. Granites isotropy and compact and heterogeneous fabric result in higher strength and lower water absorptions. Moreover, results show the negative effects of water over stones strength and elastic parameters. [ABSTRACT FROM AUTHOR]

• Effective URM wall-to-horizontal diaphragm connections prevent seismic mechanisms. • Experimentally calibrated connection models should be developed and used. • Steel anchors enhance the PO and shear behavior effectively. • Global FEM or EF seismic analyses usually neglect nonlinear connection behavior. • Nonlinear kinematic and rocking models are useful for the local seismic assessment. Wall-to-horizontal diaphragm connections play a crucial role in the global stability of historical buildings under seismic actions. When these links are ineffective or absent, engineered measures should be considered to enhance the earthquake-resistant box-type behavior. Besides the great variety on the construction systems and materials, common damages were observed in recent seismic events showing the high vulnerability of local mechanisms promoted by the lack of structural integrity. Although the acknowledged importance of connections, this topic has been practically neglected over time among the research community and practitioners and only few of them focused on the influence of diaphragm-to-wall connections on the dynamic behavior of the building as a whole. This paper presents a literature review of the traditional wall-to-floor or wall-to-roof connections in unreinforced masonry buildings and summarizes typical and innovative strengthening solutions, taking into account the indications provided by the few design codes addressing this topic. Experimental laboratory researches are investigated, including shaking table tests on global and local scale, and cyclic or monotonic tests to characterize anchoring systems. An overview of the typical vulnerability assessment approaches and modelling techniques is given, considering present standards that account for connections. [ABSTRACT FROM AUTHOR]

A probabilistic analysis approach for reliability-based assessment of masonry arch bridges is presented in this work. The methodology is tested on a medieval in-service construction located in Galicia, northwest of Spain. To estimate its ultimate load-carrying capacity, two different numerical approaches are employed; a three-dimensional non-linear finite element model and a two-dimensional rigid blocks limit analysis model. Aiming to alleviate the computational burden associated with the probabilistic analysis procedure, a surrogate modelling strategy is adopted. A complete understanding of the influence of model input parameters on the limit load of the structure is attained through the employment of global variance-based sensitivity analysis. The reliability assessment procedure is subsequently carried out, allowing to estimate the bridge failure probability. A difference of approximately 33% is obtained between the reliability index values drawn from both structural modelling strategies, so revealing the key role played by transversal effects on the strength capacity of masonry arch bridges. The proposed probabilistic assessment framework might be deemed as a useful tool, from which more reliable and objective information about the actual safety condition of existing masonry arch bridges can be derived, taking advantage of readily available numerical tools, but still demanding an affordable computational effort. [ABSTRACT FROM AUTHOR]

Highlights • The behaviour of rammed earth was investigated under compression and shear loading. • The repair effectiveness of clay- and lime-based grouts was compared. • The clay- and lime-based grouts present similar repair performance. • The injection repair was unable to recover the interlocking of the coarse particles. • Sonic tests were not sufficiently sensitive to evaluate the repair effectiveness of injection. Abstract Earth constructions constitute an important part of the built heritage and are spread worldwide. Rammed earth is among the most used earth construction techniques, though it exhibits a high seismic vulnerability. Nevertheless, the structural behaviour of rammed earth structures is still insufficiently comprehended. Thus, the preservation of this built heritage requires exhaustive characterisation of its mechanical and structural behaviours, as well as the development and validation of adequate intervention solutions. In this context, this paper presents an experimental program aimed at evaluating the effectiveness of grout injection to repair cracks and at further characterising the in-plane shear behaviour of rammed earth walls. The experimental program included the testing of rammed earth wallets under diagonal compression, which were subsequently repaired with injection of a clay-based or a hydraulic lime-based grout, and retested. Furthermore, sonic tests were conducted on the wallets before the destructive tests. The obtained results allowed to highlight that both grouts led to similar repairing performances, though the interlocking contribution promoted by the coarse particles of the rammed earth to the shear behaviour was found to be irrecoverable. [ABSTRACT FROM AUTHOR]

Abstract The use of Textile Reinforced Mortar (TRM) composites for Externally Bonded Reinforcement (EBR) of reinforced concrete (RC) and masonry structures has attracted several attentions during the last years. The effectiveness of these composites in structural reinforcement is significantly dependent on the TRM-to-substrate and the fiber-to-mortar bond behavior. Despite the importance of the latter, that controls the crack distribution on these composites, have received few attentions and is relatively unknown. This paper presents a combined experimental and analytical study on the effect of fiber-embedded length and configuration on the pull-out response. From the obtained results, bond-slip laws are proposed for TRM composites made of unidirectional and bidirectional grids. The tests are performed on a (unidirectional) steel-based and a (bidirectional) glass-based TRM composite as common reinforcing systems. A comparison is also made between the results obtained from single-fiber pull-out tests and conventional single-lap shear bond tests to highlight the differences/similarities between these two test methods. [ABSTRACT FROM AUTHOR]

• Study of thirteen TRM composites with glass and high-strength steel fabrics, examining their tensile behavior. • Comparison of gripping methods: gripping of mortar vs. gripping of textiles, to assess TRM performance on tensile test. • Investigation of the effects of textile layers, arrangement, and mortar thickness in different setups. • Use of digital image correlation (DIC) to analyze cracking patterns and failure phenomena. • Valuable insights for designing and testing TRMs, improving their tensile behavior. Textile-reinforced mortar (TRM) systems are a popular solution for strengthening existing masonry structures these days. The vast application of these materials requires a thorough study of their properties and performance. The tensile behavior of TRMs has a significant role in their mechanical properties and requires a reliable setup to record their performance. Studies in the past focused on different gripping systems and setups for characterizing tensile behavior, but harmonization is still lacking. The present study aims at presenting a suitable setup for tensile testing. To this aim, two different TRM systems were utilized. Four different setups for the clamping of coupons were used: three of them were based on gripping textiles directly, while the other one was based on gripping the mortar. Also, the effect of the textile-to-mortar strength ratio variation was studied for different setups, and using a different number of plies and different mortar thicknesses. Furthermore, digital image correlation was used for all specimens to track cracking patterns and failure modes. Finally, a comprehensive discussion of the results is presented, and the most suitable testing setup is recommended. [ABSTRACT FROM AUTHOR]

Textile-reinforced mortars (TRM) have recently received significant attention for the externally bonded reinforcement (EBR) of masonry and reinforced concrete structures. The fiber-to-mortar bond, the TRM-to-substrate bond, and the mechanical properties of the TRM constituents have a fundamental role in the performance of this strengthening technique and therefore require special attention. Despite this importance, only few investigations are devoted to characterization of the single fiber-to-mortar bond response in these systems. This paper, as an step towards addressing the fiber-to-mortar bond, presents a combined experimental and analytical investigation on the effect of test setup on the pull-out response and bond-slip laws in TRM composites. Three different pull-out test setups, consisting of one pull-pull and two pull-push configurations, are developed and investigated for characterization of the single fiber-to-mortar bond behavior. The experimental and analytical results are critically discussed and presented and bond-slip laws are extracted for each test setup. [ABSTRACT FROM AUTHOR]

Despite the use of rammed earth became marginal in the second half of the past century, Portugal still holds an important built heritage. Recently, a growing use of rammed earth has been observed in modern constructions, but it is putting aside the roots of traditional rammed earth construction. The seismic behaviour of rammed earth buildings is still insufficiently comprehended, constituting a matter of great concern, since most of the traditional dwellings are built on regions with important seismic hazard. Moreover, the complex architecture of modern rammed earth buildings is expected to make their seismic behaviour even more fragile. This paper intends to provide a better comprehension on the seismic behaviour of rammed earth constructions from Portugal. For this purpose, twenty traditional dwellings were evaluated on the basis of a simplified approach, while a modern construction was investigated by means of destructive and non-destructive testing approaches. The main findings of these approaches are discussed in detail, but it can be highlighted that the architectural features of traditional rammed earth buildings benefit their seismic behaviour, while the complex architecture of modern rammed earth buildings demands using advanced engineering tools for their seismic assessment. [ABSTRACT FROM AUTHOR]

The demand for building materials and techniques with reduced environmental impact has been increasing in the last few years. Thus, efforts have been taken to include alternative raw materials with reduced extraction impacts and low embodied energy in their production, namely natural materials and industrial by-products with low or no processing needs. Nevertheless, the lack of technical knowledge about this type of materials leads to issues related with its safety, quality and durability. The work presented in this paper intends to be a contribution on this topic. Thus, an experimental program was carried out to evaluate the mechanical performance of interlocking compressed earth blocks (ICEBs) stabilised with activated alkali fly ash. The main objective of the experimental program was to assess the possibility of further exploiting the mechanical performance of the original dry-stack masonry system, by means of the use of mortared joints. Two alkali-activated binder based earth mortars were used for this purpose, and the results showed that a substantial mechanical improvement is obtained in terms of compression and shear behaviour of the respective masonry. [ABSTRACT FROM AUTHOR]

The demand for building materials and techniques with reduced environmental impact has been increasing in the last few years. Thus, efforts have been taken to include alternative raw materials with reduced extraction impacts and low embodied energy in their production, namely natural materials and industrial by-products with low or no processing needs. Nevertheless, the lack of technical knowledge about this type of materials leads to issues related with its safety, quality and durability. The work presented in this paper intends to be a contribution on this topic. Thus, an experimental program was carried out to evaluate the mechanical performance of interlocking compressed earth blocks (ICEBs) stabilised with activated alkali fly ash. The main objective of the experimental program was to assess the possibility of further exploiting the mechanical performance of the original dry-stack masonry system, by means of the use of mortared joints. Two alkali-activated binder based earth mortars were used for this purpose, and the results showed that a substantial mechanical improvement is obtained in terms of compression and shear behaviour of the respective masonry. [ABSTRACT FROM AUTHOR]

In this work a multidisciplinary approach for the structural assessment of masonry arch bridges is presented. The Vilanova Bridge, located in Galicia, northwest of Spain, is considered for the implementation of the methodology. A comprehensive field survey fully based on non-destructive testing techniques, which integrates laser scanning, ground penetration radar, sonic tests and ambient vibration testing, is proposed. It provides all the necessary geometric data to build an accurate and detailed three-dimensional finite element model. The calibration of the model is then carried out through the coupling with an optimization algorithm, which minimizes the discrepancies with respect to the experimentally obtained modal properties. The structural analysis of the bridge is addressed in the last stage. A sensitivity analysis involving different loading scenarios and the plausible variation of the masonry and soil material properties is performed. The results demonstrate the significant influence of tensile non-linear properties of masonry, but also the key role played by fill materials on the arch bridge performance. Lastly, the advantages of adopting a three-dimensional modelling approach are also pointed out, since the apparition of critical transverse effects in the response of the structure is successfully captured by the developed numerical model. [ABSTRACT FROM AUTHOR]

Textile Reinforced Mortars (TRMs) have found extensive attention for externally bonded reinforcement of masonry and historical structures. However, only few information is available regarding their mechanical properties and effectiveness in improving the seismic performance of strengthened structures. This paper presents an extensive numerical investigation on the effect of TRM composites on the nonlinear response and failure modes of masonry walls. The effect of boundary conditions and the TRM type on the performance of strengthened walls are critically discussed and presented. It is shown that the performance and failure mode of the walls can significantly change after strengthening, an important issue that should be considered at the design stage. Finally, the effect of TRM application on the nonlinear response of a large historical masonry façade in Macau is investigated and presented. [ABSTRACT FROM AUTHOR]

Considering the safety assessment requirements of masonry arch bridges, different levels of reliability, based on uncertainty, may be distinguished, whose core objectives are to accurately analyse the ultimate load-carrying capacity and the serviceability structural response. Within this framework, a simplified full-probabilistic methodology for the safety assessment of existing masonry arch bridges is proposed, which combines both structural analysis and Bayesian inference procedures. The proposed framework aims to determine the ultimate load-carrying capacity (Ultimate Limit State) of masonry arch bridges, by using probabilistic procedures and Limit States principles. Geometric, material and load characterization, as well as inherent uncertainties will be also considered. In order to determine the ultimate load-carrying capacity, a limit analysis approach, based on the mechanism method, will be employed. Due to the high computational costs required by a probabilistic safety assessment framework, a sensitivity analysis will then be introduced. The incorporation of new information from monitoring and/or testing will be performed by the application of Bayesian inference methodologies. Based on the information collected, two reliability indexes will be computed and compared, one with data collected from design documentation and literature and the other with data collected from testing, emphasizing the importance of testing and the advantages of Bayesian inference procedures. The probabilistic framework developed is tested and validated in a Portuguese railway masonry arch bridge from the 19th century. [ABSTRACT FROM AUTHOR]

This cross-sectional web-based study investigated the association of age, gender, and symptoms of depression, anxiety, and stress with eating problems in Brazilian adults during the COVID-19 pandemic. A total of 715 participants (237 men and 478 women) were recruited from all regions of Brazil. The instruments used were the Depression, Anxiety and Stress Scale-21 (DASS-21) and the Eating Attitudes Test -- 26 (EAT-26). Data analysis was conducted through the independent t test, Pearson's correlation, and multiple regression analysis. Multiple regression showed that DASS total score made the largest positive contribution to EP for men (β = .17, p < .01) and women (β = .22, p < .001). The data showed significant differences between men and women for all variables (p < .001), indicating that women presented more symptoms in all variables. Our findings show that symptoms of depression, anxiety, and stress were associated whit risky behavior for EP in Brazilian adults during the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

This study aimed to analyze the predictive role of muscle dysmorphia symptoms in exercise addiction and orthorexia in 158 Brazilian exercise practitioners (running = 38, crossfit = 85, bodybuilding = 35) of both sexes (women = 81, men = 77), with a mean age of 31.59 years (± 7.99) and experience of 4.5 years (± 5.27). The Dedication to Exercise Scale, the Questionnaire for the Diagnosis of Orthorexia, and the Complex in Adonis Questionnaire were used. Data analysis was conducted through Pearson's correlation and multiple regression analysis (p < .05). It was found that the muscle dysmorphia symptoms predicted positively exercise addiction (β = .51, p < .001) and negatively orthorexia (β = -.19, p < .01), and it is important to discuss the issue with physical exercise practitioners in order to minimize the prevalence and deleterious effects associated with this psychological disorder. [ABSTRACT FROM AUTHOR]

• A new numerical modeling strategy for FRCM strengthened curved masonry structures. • High accuracy combined with low computational costs. • A small number of mechanical parameters is needed, easy to experimentally determine. • Large sensitivity analysis on the effect of variations of mechanical parameters. • Application to the evaluation of the seismic capacity of an FRCM reinforced vault. Fabric Reinforced Cementitious Matrix (FRCM) composites are currently considered a very effective solution for strengthening masonry constructions. However, the mechanical interactions governing the response and the strength of FRCM reinforced masonry structures are very complex, especially in the case of curved structures. Moreover, these interactions involve several interfaces between different materials. Thus, the development of accurate numerical models for curved FRCM reinforced masonry structures comes up against several difficulties, and models too complex for practical applications can be obtained. In addition, several mechanical parameters needed for the calculations are generally inaccessible by conventional experimental tests. Here, a suitable numerical modelling strategy for FRCM strengthened curved masonry structures is proposed to combine the accuracy in simulating the actual behaviour in terms of stiffness, strength and collapse mechanisms with a reasonable simplicity, making the proposed approach usable also by practitioners, by adopting commercial codes and at a moderate computational effort. The relatively small number of mechanical parameters characterizing the model can be determined by ordinary experimental tests on materials or by literature formulations. The proposed modelling strategy is validated with respect to experimental data found in literature concerning a FRCM reinforced masonry barrel vault, and then is employed for studying the seismic capacity of the vault through a pushover analysis. A broad sensitivity analysis sheds light on the effect of variations of the mechanical parameters on the predicted overall behaviour, showing the robustness of the results obtainable through the proposed approach concerning inaccuracies in the determination of the parameters often very difficult to determine by ordinary experimental tests on masonry structures. [ABSTRACT FROM AUTHOR]

Background: A large collection of sequenced mycobacteriophages capable of infecting a single host strain of Mycobacterium smegmatis shows considerable genomic diversity with dozens of distinctive types (clusters) and extensive variation within those sharing evident nucleotide sequence similarity. Here we profiled the mycobacterial components of a large composting system at the São Paulo zoo. Results: We isolated and sequenced eight mycobacteriophages using Mycobacterium smegmatis mc²155 as a host. None of these eight phages infected any of mycobacterial strains isolated from the same materials. The phage isolates span considerable genomic diversity, including two phages (Barriga, Nhonho) related to Subcluster A1 phages, two Cluster B phages (Pops, Subcluster B1; Godines, Subcluster B2), three Subcluster F1 phages (Florinda, Girafales, and Quico), and Madruga, a relative of phage Patience with which it constitutes the new Cluster U. Interestingly, the two Subcluster A1 phages and the three Subcluster F1 phages have genomic relationships indicating relatively recent evolution within a geographically isolated niche in the composting system. Conclusions: We predict that composting systems such as those used to obtain these mycobacteriophages will be a rich source for the isolation of additional phages that will expand our view of bacteriophage diversity and evolution. [ABSTRACT FROM AUTHOR]

This article presents a novel segmentation algorithm that allows the automatic segmentation of masonry blocks from a 3D point cloud acquired with LiDAR technology, for both stationary and mobile devices. The point cloud segmentation algorithm is based on a 2.5D approach that creates images based on the intensity attribute of LiDAR systems. Image processing algorithms based on an improvement of the marked-controlled watershed was successfully used to produce the automatic segmentation of the point cloud in the 3D space isolating each individual stone block. Finally, morphologic analysis in two case studies has been carried out. The morphologic analysis provides information about the assemblage of masonry pieces, which is valuable for the structural evaluation of masonry buildings. [ABSTRACT FROM AUTHOR]

Recent durability studies have shown the susceptibility of bond in fiber-reinforced polymer (FRP) strengthened masonry components to hygrothermal exposures. However, it is not clear how this local material degradation affects the global behavior of FRPstrengthened masonry structures. This study addresses this issue by numerically investigating the nonlinear behavior of FRP-masonry walls after aging in two different environmental conditions. A numerical modeling strategy is adopted and validated with existing experimental tests on FRP-strengthened masonry panels. The model, once validated, is used for modeling of four hypothetical FRP-strengthened masonry walls with different boundary conditions, strengthening schemes, and reinforcement ratios. The nonlinear behavior of the walls is then simulated before and after aging in two different environmental conditions. The degradation data are taken from previous accelerated aging tests. The changes in the failure mode and nonlinear response of the walls after aging are presented and discussed. [ABSTRACT FROM AUTHOR]

• The effect of different curing conditions on TRM composites performance is investigated. • The influence of moisture content bricks on TRM-to-substrate bond behavior is investigated. • The development of the fiber-to-mortar bond behavior is influenced by the curing conditions. • The substrate initial water content affects the TRM-to-substrate bond behavior. Textile reinforced mortars (TRMs) are innovative sustainable composite materials that recently received extensive attention for strengthening of masonry structures. Understanding the mechanical performance of these composites has therefore been the subject of many recent studies. However, most of these investigations have focused on the mechanical properties of these composites under controlled laboratory conditions, and their performance under field conditions is still unknown. The critical role of substrate preparation and curing conditions on the performance of these repair systems have never been addressed before. To address this gap, this paper presents an experimental investigation on the role of these factors on the performance of two different TRM systems (a steel-based TRM and a glass-based TRM) commonly used for strengthening masonry structures. The results show the importance of these factors and the need for the identification of standard procedures for the application of these systems aiming the optimization of their performance in the field. [ABSTRACT FROM AUTHOR]

Recent research has proved the potential of alkaline activated fly-ash for soil stabilisation. However, such studies have not focused on the link between financial, mechanical and environmental aspects of this solution, but only on their absolute mechanical properties. The present paper characterises the mechanical behaviour of a large spectrum of activator-ash-soil combinations used to build jet mixing columns, analysing also the cost and CO 2 (eq) emissions. The concern with these two vectors forced a decrease in the quantity of stabilising agent added to the soil, relatively to previous research, and the effects of such low quantities have not yet been published. However, the results clearly showed a significant improve in strength, still well above the average values expected when improving the stress-strain behaviour of a weak soil. Uniaxial compressive strength tests were used to assess the effects of the fly-ash percentage, the alkali–ash ratio and the water content. The carbon calculator recently developed by the European Federation of Foundation Contractors and the Deep Foundations Institute was used to quantify the CO 2 (eq) emissions associated with this technique. The financial cost was estimated based on the experience of a major Portuguese contractor. For comparison purposes, soil-cement mixtures were also analysed, using similar conditions and tools used for the soil-ash analysis. Results showed that the cement and ash solutions are very similar in terms of overall performance, with some advantage of the former regarding financial cost, and a significant advantage of the latter regarding the CO 2 (eq) emissions. This new grout, although it is in an embryonic stage, it has the potential for broader developments in the field. [ABSTRACT FROM AUTHOR]

The bond behavior between Fiber Reinforced Polymers (FRPs) and masonry substrates has been the subject of many studies during the last years. Recent accelerated aging tests have shown that bond degradation and FRP delamination are likely to occur in FRP-strengthened masonry components under hygrothermal conditions. While an investigation on the possible methods to improve the durability of these systems is necessary, the applicability of different bond repair methods should also be studied. This paper aims at investigating the debonding mechanisms after repairing delaminated FRP-strengthened masonry components. FRP-strengthened brick specimens, after being delaminated, are repaired with two different adhesives: a conventional epoxy resin and a highly flexible polymer. The latter is used as an innovative adhesive in structural applications. The bond behavior in the repaired specimens is investigated by performing single-lap shear bond tests. Digital image correlation (DIC) is used for deeper investigation of the surface deformation and strains development. The effectiveness of the repair methods is discussed and compared with the strengthened specimens. [ABSTRACT FROM AUTHOR]

The increasing interest on earth construction as a sustainable building solution led to the development of modern earth construction techniques, in particular of masonry made of compressed earth blocks (CEBs). The traditional chemical stabilisation of the soil is a frequently used improvement process. However, such process increases significantly the embodied energy of the CEBs. This paper presents an alternative technique for the stabilisation of CEBs, based on alkali activation of fly ash. The mechanical behaviour of the CEBs and of the respective dry stack masonry is comprehensively investigated through an experimental program, during which this technique proved to be highly effective. [ABSTRACT FROM AUTHOR]

The paper discusses the bond between fibre-reinforced polymer (FRP) strips and brick masonry, using advanced non-linear simulations of experimental test results. The context of the research is the study of the interfacial behaviour of a brittle substrate (masonry) and a thin elastic addition (the FRP) used as a strengthening system for historical structures. Moreover, to further validate the numerical results, the problem is also approached analytically. In the numerical model, the interface is represented with zero-thickness finite elements, with inelastic behaviour fully formulated using the incremental plasticity theory. The mechanical characterization of the materials involved and the local interfacial behaviour allowed defining the main parameters and the constitutive law to be adopted. Based on the experimental results, the detailed finite element model is calibrated so that it is possible to describe the bond phenomenon at the local level up to failure, identifying the strain and slip distribution, the local bond stress peak and its migration along the bond length for flat and curved layers. Numerical results and analytical predictions show a good agreement with experimental data, allowing to provide a comprehensive discussion on the bond behaviour. Moreover some differences between interfacial behavior of FRP–masonry/concrete joints are highlighted. Finally applications of the model to analyze strengthened structural components (such as masonry arches) are provided. [ABSTRACT FROM AUTHOR]

Out-of-plane failure mechanisms observed in stone masonry buildings subjected to seismic action are often a direct result of poor connections between structural elements. During a seismic event these weak connections become incapable of assuring proper load transmission. Therefore, the need to prevent these phenomena is of critical importance in understanding the behavior of unstrengthened masonry buildings along with the necessity of developing effective strengthening solutions. This paper presents injection anchors as a viable option to improve anchorage between masonry and timber elements on historical buildings, as for example wall-to-timber framed wall or wall-to-timber diaphragm connections. The experimental campaign consisted of quasi-static monotonic and cyclic pullout tests performed on real scale specimens, representative of wall-to-timber framed wall connections found in late 19th century buildings of downtown Lisbon, Portugal. Combined cone-bond failure was obtained in all 7 tests. Boundary conditions of the specimens greatly affected the results in terms of maximum pullout force, dissipated energy, and strength degradation. Displacement ductility of the strengthened connections is high. The force–displacement curves clearly pointed out the influence on the results of the wall’s compressive stress state and the contribution of friction in the grout/masonry interface. [ABSTRACT FROM AUTHOR]

Highlights: [•] Development of macroauxetic structures from braided composite rods. [•] Measuring dimensional change of the structures using an image based tracking method. [•] Poisson’s ratio of the auxetic structures depends on initial structural angle. [•] The energy absorption ability of the structures improved with high initial angle. [Copyright &y& Elsevier]

Highlights: [•] Steel reinforced grout is used for strengthening bricks and bond behavior is investigated experimentally and numerically. [•] Between mortar curing time and brick surface preparation, the latter influences remarkably the bond performance. [•] The numerical model of the experiments is introduced comprising of bond–slip laws obtained through inverse fitting procedure. [•] The effect of some design parameters on the overall bond behavior is studied using the validated numerical model. [Copyright &y& Elsevier]

Abstract: Full characterization of the bond behavior between Fiber Reinforced Polymers (FRPs) and masonry in externally bonded reinforcement (EBR) technique is crucial at the design stage or structural performance prediction. In this regard, a full-field assessment technique seems to be valuable for an adequate characterization of the bond behavior. The digital image correlation (DIC) and feature tracking techniques have been used in this study for investigating the evolution of strains and deformation during uniaxial tensile tests and shear debonding tests in FRP-masonry systems. The results show that the DIC is a valuable technique for characterization of the bond behavior and investigating its three-dimensional aspects. The DIC was also found applicable for following the matrix crack development in Steel Reinforced Grout (SRG) specimens. Feature tracking method was used for monitoring the strains development on the steel fibers in SRG specimens during tensile tests. [Copyright &y& Elsevier]

Abstract: Fiber reinforced polymers are being extensively used for external strengthening of masonry structures. However, durability of this strengthening technique under environmental conditions is still under investigation. Previous studies indicate that moisture plays an important role in the durability of bond between FRP and substrate. Moisture can cause degradation in the bond behavior and also in the mechanical properties of the constituent materials. This paper presents and discusses the results of an experimental investigation on the effects of moisture on the bond behavior in FRP-strengthened masonry bricks. The degradation in the bond performance has been investigated by performing pull-off and pull-out tests on the conditioned specimens. The change in the mechanical properties of the materials has also been investigated. Comparative analysis has been performed and the results are presented and critically discussed. [Copyright &y& Elsevier]

Abstract: The paper discusses the behavior of a typical masonry building in Bosnia and Herzegovina built in the 1950s without any seismic guidelines. A global numerical model of the building has been built and masonry material has been simulated as nonlinear. Additionally, calculations done with a “less” sophisticated model are in a good correlation with the finite element method (FEM) calculations. It was able to “grasp” the damage pattern; not as detailed as in the FEM calculations, but still quite good. On the basis of this it may be concluded that in this case calculation with Frame by Macro Elements (FME) program could be recommended for future analysis of this type of structures, having quite good results with a less computation time. However, in the need for more precise results FEM should be utilized. [Copyright &y& Elsevier]

Abstract: Fiber Reinforced Polymers have become a popular material for external strengthening of masonry structures. The performance of this strengthening technique is strongly dependent on the bond between FRP and substrate. This paper presents numerical modeling of the bond behavior in FRP-strengthened masonry components using interface elements, based on a recent testing program at the University of Minho. A trilinear bond–slip model is proposed for the interface elements based on observed experimental behavior of strengthened components. The comparison between numerical and experimental results shows that the proposed model is suitable for numerical simulation of the bond behavior and allows a better understanding of the mechanisms involved in the failure process. [Copyright &y& Elsevier]

• FT effects on the bond behavior of lime-based TRM composites is investigated. • 330 pull-out tests are performed on steel and glass-based TRM composite. • Effect of different fiber configuration and embedded lengths are analyzed. • Deterioration level of bond behavior depends on the fiber architecture. • Results contribute to the development of TRM composites with enhanced properties. Textile reinforced mortars (TRMs) have emerged as a sustainable solution for strengthening existing masonry and concrete structures. As a result, many recent studies have focused on understanding the performance of these composites. However, most of these are aimed at investigating the mechanical properties of TRM composites. At the same time, their durability and long-term performance remain poorly addressed and unclear. This paper presents an experimental study on the effect of freeze–thaw environmental conditions on the micro-mechanical behavior of these composites. The results indicate that the freezing-thawing exposure conditions considered in this study do not have detrimental effects on the mortar strength. However, the fiber-to-mortar bond behavior can deteriorate because the deterioration level depends on the fiber type, embedded length, and fiber configuration. [ABSTRACT FROM AUTHOR]

• Pull-out behavior of different TRM/FRCM composites is deeply investigated. • Bond-slip law predicts the slip hardening and softening effects. • Bond-slip law of the effective length predicts load-slip curves of different lengths. • The proposed bond-slip law models the pull-out response of a range of TRM composites. • Effect of mortar age on the bond-slip law parameters is investigated. Reliable design and application of textile-reinforced mortar (TRM) composites for the repair of existing masonry and concrete structures requires a fundamental understanding of the textile-to-mortar bond behavior as one of the main mechanisms controlling their nonlinear response and cracking behavior. Suitable test setups and analytical models are needed to extract the bond-slip laws from the experimental pull-out tests. This paper proposes a new bond-slip law and analytical model, which predicts the bond behavior of lime and cement-based TRM composites considering the slip hardening and softening effects observed in experimental tests. For this purpose, the pull-out response of experimental specimens with different fiber types (steel and glass), bond lengths, and mortar age are analyzed, and their bond slip-laws are extracted. The accuracy of the developed model is shown by comparing analytical and experimental results. [ABSTRACT FROM AUTHOR]