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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.

In the last decade, textile-reinforced mortar (TRM) composites have been introduced as a sustainable solution for the strengthening of masonry structures. As an externally bonded reinforcement system, it consists of textile fibers embedded in an inorganic matrix (e.g., lime or cement mortar) applied to the substrate. Even though many studies have been focused on characterizing the mechanical behavior of TRM composites in recent years, there are still some drawbacks, including their tensile performance and few studies about multilayer textiles arrangement. This work aims at clarifying the effect of adding a second textile layer to TRM composites and investigating how textile arrangement affects the tensile behavior of the composite system. For this purpose, AR-glass and steel-based TRM composites were used in single layer and multilayer with different arrangements embedded in a lime-based mortar. The results show that using two plies of textile mesh improves the tensile response of TRM composites. In addition, it is found that the arrangement of different layers in the matrix influences the TRM response in different stress stages. The addition of a thin layer of mortar between two layers seems to improve the stiffness in uncracked condition and slightly decreases the final strength of TRM. Thus, the present study makes a step toward optimizing the arrangement of textiles in multilayer TRM composites.

Fiber reinforced polymers (FRP) have been widely used for strengthening and repair of masonry structures since the 1990s. Although the short-term performance of such systems has been extensively studied, their durability and long-term behavior are still scarcely known. Therefore, a better understanding of the corresponding degradation mechanisms and durability issues is of major interest, especially in cases of externally bonded systems where the materials are prone to undergo a more severe decay. Different accelerated aging tests have been developed in order to simulate weathering conditions in a shorter time: water immersion, freeze-thaw, hygrothermal cycles, salt crystallization, UV radiation, etc. Nonetheless, accelerated aging data cannot be used to make reliable service life estimations without a clear correlation with real environmental processes. In this study, we present the preliminary results (3/12 years) of a real exposure experimental campaign devoted to analyzing the natural aging of masonry components reinforced with externally bonded glass fibers (GFRP). The aging conditions consist of: (a) direct outdoor exposure, i.e. outdoor hygrothermal variation + sun and rain; (b) indirect outdoor exposure, i.e. outdoor hygrothermal variation + sheltered from sun and rain; (c) laboratory conditions as control group. The specimens consist of solid extruded fired-clay bricks strengthened with unidirectional GFRP sheets following the wet lay-up procedure. The aging effects on bond performance are studied by means of single-lap shear tests. Finally, the effect of brick surface treatment and the application of an external render on bond durability is investigated.

Despite all the advantages of applying natural fibers in structural composites, their expected short life span constitutes a challenge due to their hydrophilicity and deterioration in alkaline lime or cement matrices. The present paper proposes eco-friendly hydrophobic coatings to protect natural fibers in lime mortars resorting to polymers reinforced with hydrophobic beeswax micro colloids. The physical, mechanical and chemical characterization suggest the potential of the coated fibers for NTRM casting and further investigation of their interface and bond behavior with the mortar.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common monogenic form of familial small vessel disease; no preventive or curative therapy is available. CADASIL is caused by mutations in the NOTCH3 gene, resulting in a mutated NOTCH3 receptor, with aggregation of the NOTCH3 extracellular domain (ECD) around vascular smooth muscle cells. In this study, we have developed a novel active immunization therapy specifically targeting CADASIL-like aggregated NOTCH3 ECD. Immunizing CADASIL TgN3R182C(150) mice with aggregates composed of CADASIL-R133C mutated and wild-type EGF(1-5) repeats for a total of 4 months resulted in a marked reduction (38-48%) in NOTCH3 deposition around brain capillaries, increased microglia activation and lowered serum levels of NOTCH3 ECD. Active immunization did not impact body weight, general behavior, the number and integrity of vascular smooth muscle cells in the retina, neuronal survival, or inflammation or the renal system, suggesting that the therapy is tolerable. This is the first therapeutic study reporting a successful reduction of NOTCH3 accumulation in a CADASIL mouse model supporting further development towards clinical application for the benefit of CADASIL patients.

Background and AimsAlagille syndrome (ALGS) is a pediatric genetic disorder, caused by mutations in the Notch ligandJAGGED1, presenting with cholestasis due to intrahepatic bile duct paucity. Despite chronic liver disease, few patients develop severe fibrosis or liver cancer, compared to other chronic liver diseases. In contrast, about 1/3 of ALGS patients suffer from reoccurring infections. Notch signaling regulates both liver and immune system development, but how immune system defects interact with liver pathology in ALGS to influence disease course is not known. Here, we aimed to determine whether a mouse model of ALGS mimics fibrosis and liver cancer, and whether ALGS immune system compromise could positively modulate inflammation or liver disease course.MethodsWe used single cell RNA sequencing and 25-color flow cytometry to characterize cell populations in embryonic and postnatal liver in an ALGS mouse model (Jag1Ndr/Ndrmice). We analyzed liver cancer prevalence inJag1Ndr/Ndrmice, in a cancer-prone genetic background, and thymic and spleen cell composition using flow cytometry. Finally, to test the functionality of theJag1Ndr/Ndrimmune system we performed adaptive immune cell transfer experiments intoRag1-/mice and assessed inflammatory capacity in an ulcerative colitis model and in a DDC model of hepatocellular damage.ResultsAdultJag1Ndr/Ndrmice do not develop liver tumors (0%) while 45% of control mice do. Interestingly,Jag1Ndr/Ndrmice display ALGS-like chicken-wire hepatocellular fibrosis concomitant with mild inflammation shortly after the onset of liver cholestasis. Comprehensive single cell analysis revealed that liver CD4+and CD8+T cells ofJag1Ndr/Ndrmice are dysregulated in favor of CD4+, and Regulatory T-cells (Tregs) manifest reduced activation. Transplantation experiments show no difference betweenJag1Ndr/NdrandJag1+/+lymphocytes in DDC-induced liver damage. In contrast,Jag1Ndr/Ndrlymphocytes do not mount an inflammatory response to bacterial infection.ConclusionHere we report immune dysregulation and cancer protection in the hypomorphicJag1mouse model of ALGS. Disrupted thymocyte differentiation coincides with limited activation of hepatocytes, blunting the inflammatory response to cholestasis. This may contribute to the pericellular fibrosis and prevent carcinogenesis. These results prompt the question of the relative contribution of Jag1 to liver cell pathology vs immune system in ALGS and highlight the need of future studies focused on dissecting apart how Jag1 modulates susceptibility to infection versus cancer risk.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common monogenic form of familial small vessel disease and no preventive or curative therapy is available. CADASIL is caused by mutations in the NOTCH3 gene, resulting in a mutated NOTCH3 receptor, with aggregation of the NOTCH3 extracellular domain (ECD) around vascular smooth muscle cells. In this study we have developed a novel active immunization therapy specifically targeting CADASIL-like aggregated NOTCH3 ECD. Immunizing CADASIL TgN3R182C150 mice with aggregates composed of CADASIL-R133C mutated and wild type EGF1-5 repeats for a total of four months resulted in a marked reduction (38-48%) in NOTCH3 deposition around brain capillaries, increased microglia activation and lowered serum levels of NOTCH3 ECD. Active immunization did not impact body weight, general behavior or the number and integrity of vascular smooth muscle cells in the retina, suggesting that the therapy is tolerable. This is the first therapeutic study reporting a successful reduction of CADASIL-like NOTCH3 accumulation in mice supporting further development towards clinical application for the benefit of CADASIL patients.

Building Information Modelling (BIM) methodology is becoming widespread with many potential uses, such as facility and asset management for new buildings. Recently, it has also been applied for the...

Natural fibers are getting a huge interest amongst researchers due to their green, economical and good mechanical properties when employed in different composites as reinforcements. In this work we pre- sent a review on the applications of natural fibers, essentially as composites, for structural purposes with focus on repairing and strengthening of cultural built heritage. Different testing methods with their results combined with the studying of the enhancements attained by applying natural fiber composites, e.g. textile reinforced mortar (TRM), to weak masonry are discussed. Durability challenges mainly due to the hydrophilic nature of the natural fibers are discussed together with some possible solutions., Portuguese foundation for science and technology (FCT) for the PhD scholarship granted to A. Abbass (SFRH/BD/144106/2019)

Rammed earth technique is spread worldwide, representing the local identity of many cultures for which they must be preserved. Yet, rammed earth heritage is also well known for its high seismic vulnerability and despite the increasing concern for this aspect, few investigations were conducted on dynamic response of such structures. In this framework, an experimental program was undertaken on a rammed earth mock-up by means of shake table tests carried out at the National Laboratory of Civil Engineering (LNEC) in Lisbon. To investigate the out-of-plane behaviour of rammed earth walls, a mock-up was built in real scale with a U-shape and then subjected to a series of increasing seismic inputs. The results are here discussed in terms of damage, displacements and base shear coefficient. In conclusion, the model behaved as a rigid block to earthquake excitations.

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., This research was developed at the University of Minho in close cooperation with the following entities: Adao da Fonseca, COST Action TU 1406, GEG, HDP, IABSE, Portuguese Infrastructures, Mota Engil and Soares da Costa. This work was partly financed by: (i) FEDER funds through the Competitivity Factors Operational Programme (COMPETE) and by national funds through the Foundation for Science and Technology (FCT) within the scope of project POCI 01 0145 FEDER 007633; (ii) national funds through FCT - Foundation for Science and Technology, under grant agreement "PD/BD/143003/2018" attributed to the 1st author; and (iii) FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020.

Earthen heritage represents an important legacy regarding construction history and technological development, with a significant cultural value that must be preserved. According to UNESCO, around 10% of the World Heritage is built using earth, and 57% of these heritage structures are in danger. Although the interest regarding earthen heritage has grown in the last few years, there is still a significant lack of knowledge in terms of material characterization, especially from conservation science point-of-view. In particular, tests regarding water absorption are always difficult to perform with a material that changes completely when in contact with water. Indeed, due to the presence of clay particles, a normal capillarity test is almost impossible to perform. Moreover, water is responsible for a significant number of degradation phenomena often found in earthen heritage. As a result, there is an urgent need to develop suitable water repellent treatments and to evaluate their efficiency. For this reason, this study focuses on the contact sponge method to assess water absorption rates for adobe and for rammed earth specimens treated with three different water repellents - siloxane, linseed oil, and beeswax. Two sets of specimens were prepared and tested, showing that this method can represent an effective way to measure initial water absorption in earthen materials, and promising results from the tested water repellent treatments were found., The support from grant PD/BD/114411/2016 is gratefully acknowledged. This work was partly financed by FEDER funds through the Operational Program Competitiveness Factors (COMPETE 2020) and by national funds through the Foundation for Science and Technology (FCT) within the scope of project SafEarth PTDC/ECM-EST/2777/2014 (POCI-01-0145-FEDER-016737).

There has been considerable attention drawn to the application of textile reinforced mortar (TRM) composites for strengthening existing masonry and concrete structures. These composites are made from textile fibers embedded in an inorganic matrix and act as externally bonded reinforcement (EBR). Therefore, a careful observation must be made of the bond of the mortar to the substrate and the bond of the mortar to the textile. Despite numerous studies of the bond behavior of TRM composites conducted in recent years, no constitutive bond behavior law under cyclic loading has been determined. In most available studies, the most common method of testing TRM-to-substrate bonds is the single-lap shear test. Contrary to that, the bond performance of fibers to mortar has received little attention and has been the subject of this study. This paper describes a laboratory study investigating the textile's interfacial bond behavior to the mortar fiber under cyclic loading. It was shown that cycling can cause a loss in strength, which varies with the number of cycles.

Earth is an ancient construction material that is attracting numerous scientific investigations due to the sustainable characteristics of this material and the significant heritage of existing earth constructions. Several studies have recently been conducted to investigate the seismic performance of earth buildings. This chapter presents the state of the art related to the seismic performance of earth structures. Since the seismic performance of a structure depends both on the dynamic and static characteristics of the material and the structure, the chapter starts with a summary of the static characteristics, followed by the results on the dynamic characteristics. Then the existing methods for the earthquake performance evaluation are presented. Finally, the techniques of seismic strengthening are cited and discussed. This chapter is a useful repertoire for further studies on the seismic design of earthen structures., This chapter is prepared in the case of the RILEM Technical Committee TC 279-TCE (Testing and characterisation of earth-based building materials and elements). The authors wish to thank the French National Research Agency (ANR) for funding the PRIMATERRE project (ANR-12-Villes et Bâtiments Durables). Several results presented in this paper are the outcome of this project. The funding from the ReBuMAT project (German-Vietnamese Collaborative Project on Resource-efficient Construction using Sustainable Building Materials) is acknowledged. Part of this work was also carried out within the framework of project POCI-01-0145-FEDER-016737 (PTDC/ECM-EST/2777/2014), financed by FEDER funds through the Competitivity Factors Operational Programme—COMPETE and by FCT—Foundation for Science and Technology. The funding provided is kindly acknowledged. This work was partly financed by FEDER funds through the Competitivity Factors Operational Programme—COMPETE and by national funds through FCT—Foundation for Science and Technology within the scope of project SafEarth (PTDC/ECM-EST/2777/2014).

This chapter reviews the potential impact of six environmental agents (water, ice, wind, fire, solar radiation and chemical attack) on the long-term stability of earth buildings together with some of the most common techniques for measuring and improving material durability. Liquid water appears the most detrimental of all environmental agents, not only because it can significantly reduce capillary cohesion inside the material but also because water can penetrate inside buildings through multiple routes, e.g. rainfall, foundation rise, ambient humidity and utilities leakage. Water can also be very damaging when it is present in solid form as the expansion of pore ice may induce cracking of the earth material. The high resistance of earth buildings to wind is instead proven by the good conditions of many historic structures in windy regions. Earth buildings also exhibit good resistance to fire as the exposure to very high temperatures may even improve material durability. Solar radiation has, in general, a beneficial effect on the stability of earth buildings as it promotes water evaporation with a consequent increase of capillary cohesion. Solar radiation may, however, have a detrimental effect if the earth is stabilised by organic binders that are sensitive to photodegradation because, in this case, it may produce material damages ranging from a simple surface discoloration to a much more serious deterioration of the intergranular bonds. Unstabilized earth is generally inert and, hence, largely unaffected by chemicals though, in some instances, the precipitation of salt crystals inside the pore water can induce material cracking. Chemical degradation can instead be severe in both stabilised earth (due to the dissolution of intergranular bonds) and steel-reinforced earth (due to the corrosion of rebars). No international standard protocol exists to measure the durability of earth materials, which is currently assessed by multiple experimental procedures depending on which environmental agent is considered. Testin, (undefined)

This paper presents a multi-level experimental and analytical investigation on the mechanical performance of TRM composites used for strengthening existing masonry structures. Micro (fabric-to-mortar bond), meso (TRM-to-substrate bond), and macro (TRM tensile response and in-plane and the out-of-plane ressponse of TRM-strengthened masonry) response of TRMs are combined and investigated in-depth for this reason. These results help to understand the mechanisms controlling the response of these composites and their performance at the structural scale.

CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is the most common familial form of stroke, which is caused by mutations located in the epidermal growth factor (EGF)-like repeats of the

This paper presents an optimized washing protocol for as-received natural fibers, prior to large-scale composite manufacturing, for the structural strengthening of historic masonry. The aim was to achieve a simple protocol for standard cleaning of fiber surfaces from low molecular weight constituents that may be detrimental towards interfacial strength without damaging the fibers. The proposed procedure employs the application of the solvent sequence: ethanol, acetone, hexane, with optimized incubation times and stirring conditions. Additionally, this procedure may change the surface of the fiber, thereby enhancing the durability of the fiber-matrix interface. The washing protocol resulted in an increase of tensile strength by 56%, 52% and 22% for flax, hemp and sisal fibers, respectively, as compared to the corresponding non-washed fibers, without loss of elongation. The static contact angle measurements confirmed exposure of a higher fraction of the hydrophilic crystalline cellulose, with a higher wettability observed after washing protocols., This work was partly financed by the Portuguese Foundation for Science and Technology (FCT/MCTES) through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE) under reference UIDB/04029/2020. IPC acknowledges the support of FCT through National Funds References UIDB/05256/2020 and UIDP/05256/2020. The authors wish to acknowledge FCT for the PhD scholarship granted to the first author (SFRH/BD/144106/2019).

Throughout the last century and in recent years, several bridge failures have taken place worldwide. Recent studies uncovered that the primary cause of these collapses was human errors in the design, construction, and operation phases. Regardless of this finding, there is still a considerable gap between this information and the known errors and the risk they represent for structural safety. Aiming for a better understanding of human errors, an identification procedure and a qualitative assessment of such errors considering risk-based indicators (probability of occurrence and consequence) was performed. Several brainstorming meetings with design and construction experts led to the identification of 49 relevant human errors, which were listed for further evaluation on a survey. Much more important than identifying and assessing these errors is identifying those that pose a greater threat to safety. Using a decision-making tool (analytical hierarchy process) to process all the information collected in the survey, the errors were ranked according to risk indicators. Furthermore, a qualitative risk assessment is performed, allowing the identification of the errors denoting higher risk for structural safety, according to experts’ opinions., This research was developed at the University of Minho in close cooperation with the following entities: Adão da Fonseca, COST Action TU 1406, GEG, HDP, IABSE, Portuguese Infrastructures, Mota Engil and Soares da Costa. This work was partly financed by: (i) FEDER funds through the Competitivity Factors Operational Programme (COMPETE) and by national funds through the Foundation for Science and Technology (FCT) within the scope of project POCI 01 0145 FEDER 007633; (ii) national funds through FCT - Foundation for Science and Technology, under grant agreement “PD/BD/143003/2018” attributed to the 1st author; and (iii) FCT / MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB / 04029/2020

The aggregation of β-amyloid peptide 42 results in the formation of toxic oligomers and plaques, which plays a pivotal role in Alzheimer's disease pathogenesis. Aβ42 is one of several Aβ peptides, all of Aβ30 to Aβ43 that are produced as a result of γ-secretase-mediated regulated intramembrane proteolysis of the amyloid precursor protein. γ-Secretase modulators (GSMs) represent a promising class of Aβ42-lowering anti-amyloidogenic compounds for the treatment of AD. Gamma-secretase modulators change the relative proportion of secreted Aβ peptides, while sparing the γ-secretase-mediated processing event resulting in the release of the cytoplasmic APP intracellular domain. In this study, we have characterized how GSMs affect the γ-secretase cleavage of three γ-secretase substrates, E-cadherin, ephrin type A receptor 4 (EphA4) and ephrin type B receptor 2 (EphB2), which all are implicated in important contexts of cell signalling. By using a reporter gene assay, we demonstrate that the γ-secretase-dependent generation of EphA4 and EphB2 intracellular domains is unaffected by GSMs. We also show that γ-secretase processing of EphA4 and EphB2 results in the release of several Aβ-like peptides, but that only the production of Aβ-like proteins from EphA4 is modulated by GSMs, but with an order of magnitude lower potency as compared to Aβ modulation. Collectively, these results suggest that GSMs are selective for γ-secretase-mediated Aβ production.

Due to the poor shear capacity of unreinforced masonry (URM) walls, it is necessary to strength these elements in the masonry structures. Textile-reinforced mortar (TRM) composites have received extensive attention as a sustainable solution for seismic strengthening of masonry and historical structures. This new system is composed of textile fibers embedded in an inorganic matrix such as lime-based mortar and is applied on the masonry substrate surface as an externally bonded reinforcement (EBR) system. Lime-based mortars are preferred for application to masonry and historical structures due to compatibility, sustainability issues, breathability and capability of accommodating structural movements.

Rammed earth constructions, beyond being largely spread in the built heritage, are known for their high seismic vulnerability, which results from high self-weight, lack of box behavior and low mechanical properties of the material. Hence, to mitigate this seismic vulnerability, a compatible textile reinforced mortar (TRM) is here proposed as a strengthening solution, because of its reduced mass and high ductility. The few research about the structural behavior of TRM-strengthened rammed earth elements addresses the global behavior, overlooking the local behavior of the system. An analytical approach to infer the bond stress-slip relationship following the direct boundary problem is proposed. Based on a previous series of pull-out tests, an adhesion-friction constitutive law is portrayed considering also a damage model that considers the degradation of the reinforcing fibers due to friction., This work was partly financed by FEDER funds through the Operational Programme Competitiveness Factors (COMPETE 2020) and by national funds through the Foundation for Science and Technology (FCT) within the scope of project SafEarth - PTDC/ECM-EST/2777/2014 (POCI-01-0145-FEDER-016737). The support from grant SFRH/BD/131006/2017 is also acknowledged.

The structural effectiveness of textile reinforced mortar (TRM) composites relies on their load transfer capacity to the substrate and the interaction between textile and mortar. The bond plays a crucial role in mechanism of TRM composites. Despite some recent investigations, a deep understanding still needs to be gained on the textile-to-mortar bond to develop suitable analytical and numerical predictive models, improve test methods, and orient design criteria. This work describes a laboratory study in which pull-out tests were carried out to investigate the effect of the slip rate and cyclic loading on the textile-to-mortar bond behaviour. Alkali-resistant glass fabric and sgalvanised ultra-high tensile strength steel cords embedded in two different lime-based mortars were tested. The pull-out response was sensitive to the strain rate at low rates. Cyclic loading produced a strength degradation, which reduced with the number of cycles.

The corner mechanism in masonry structures is one of the out-of-plane modes that may frequently occur under dynamic actions such as earthquakes. The three dimensional motion, in principle complex to treat, can be simplified into a two-dimensional problem, where a prismatic equivalent block is associated to the corner mechanism. This paper provides a method to treat the corner mechanism in two dimensional rocking analysis, taking into account the roof actions especially the roof thrust that acts as destabilizing force in the preliminary phases of motion and the boundary conditions such as the transverse walls. A case study is taken as benchmark to perform rocking non-linear analyses and discuss the role of geometry, energy dissipation and boundary conditions. It is shown the relevant influence of the geometry and of the coefficient of restitution on the stability conditions, whenever the oscillation produce horizontal displacement values of some cm. The results of the case study, subjected to the Central Italy earthquake, are compared to the actual response of the corner mechanism, which collapsed during this seismic swarm, showing that the rocking analysis on the equivalent block correctly predicts the collapse occurred., The Authors thank the Italian Department of Civil Protection and the Consortium RELUIS (2018) for funding this research activity. This work was partially financed by FEDER funds through the Competitiveness Factors Operational Program - COMPETE and by national funds through FCT - Foundation for Science and Technology within the scope of the project POCI-01-0145-FEDER-007633.

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 sub-assembly (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., This work was financed by FEDER funds through the Competitively Factors Operational Programme - COMPETE and by national funds through FCT - Foundation for Science and Technology within the scope of projects POCI-01-0145-FEDER-016737 (PTDC/ECM-EST/2777/2014) and POCI-01-0145-FEDER-007633. The support from grant SFRH/BPD/97082/2013 is also acknowledged.

Earthen constructions are spread worldwide, not only as architectural heritage but also as new buildings, in which a total of around one fourth of the global population is estimated to live in. Among the different raw earth techniques, rammed earth was widely used to build vernacular dwellings in different regions. Despite the raising awareness for the high seismic hazard, recognized seismic vulnerability and high seismic exposure associated with earthen structures, the reduction of their seismic risk has been a topic insufficiently addressed. In general, the seismic vulnerability of rammed earth structures is due to poor connections between structural elements (walls and floors), high self-weight and low strength of the material. Hence, a TRM-based strengthening technique is proposed to improve their seismic capacity. To estimate the enhancement of the in-plane performance achieved with the TRM, an experimental program was conducted. Rammed earth wallets were tested under diagonal compression considering their unstrengthened and strengthened condition. The TRM strengthening was performed by embedding a glass fibre mesh (GRE) or a nylon mesh (NRE) in a compatible earth-based mortar. In general, the proposed TRM-based strengthening seems to improve the shear behaviour of rammed earth by enhancing the shear strength and promoting stress distribution after cracking, while no significant influence on the shear modulus of rammed earth seems to occur., This work was partly financed by FEDER funds through the Operational Programme Competitiveness Factors (COMPETE 2020) and by national funds through the Foundation for Science and Technology (FCT) within the scope of project SafEarth - PTDC/ECM-EST/2777/2014 (POCI-01-0145-FEDER-016737). The support from grants SFRH/BD/131006/2017 and SFRH/BPD/97082/2013 is also acknowledged.

The large availability of raw earth around the World led to its extensive use as a building material through history. Thus, earthen materials integrate several historical monuments, but their main use was to build living and working environments for billions of people. On the other hand, past earthquakes revealed their inadequate seismic behavior, which is a matter of concern as a significant percentage of earthen buildings are located in regions with medium to high seismic hazard. Nevertheless, their seismic behavior and the development of efficient strengthening solutions are topics that are not yet sufficiently investigated in the literature. In this context, this study investigates numerically the in-plane seismic behavior of a rammed earth component by means of advanced nonlinear finite element modeling, which included performing nonlinear static (pushover) and nonlinear dynamic analyses. Moreover, the strengthening effectiveness of a low-cost textile-reinforced mortar on such component was also evaluated. The strengthening was observed to increase the load and displacement capacities, to preserve the integrity for higher lateral load levels and to postpone failure without adding significant mass to the system. Furthermore, the pushover analysis was shown to predict reliably the capacities of the models with respect to the incremental dynamic analysis., This work was financed by FEDER funds through the Competitively Factors Operational Programme (COMPETE) and by national funds through the Foundation for Science and Technology (FCT) within the scope of projects POCI-01-0145-FEDER-016737 (PTDC/ECM-EST/2777/2014) and POCI-01-0145-FEDER-007633. The support from grant SFRH/BPD/97082/2013 is also acknowledged.

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., This work was financed by FEDER funds through the Competitively Factors Operational Programme (COMPETE) and by national funds through the Foundation for Science and Technology (FCT) within the scope of projects POCI-01-0145-FEDER-016737 (PTDC/ECM-EST/2777/2014) and POCI-01-0145-FEDER-007633.

Bridges present valuable assets for the rail and road network by providing cross at critical links such as waterways, valleys, and other types of facilities. However, these types of structures are exposed to several threats during their lifecycle such as natural hazards and deterioration, which compromise their performance. To assess the condition state of such infrastructure and define maintenance and mitigation strategies, several performance indicators of quantitative nature have been proposed during the last decades by several researchers. Among those indicators, risk has received great attention as it enables to account for both the performance of infrastructures subjected to hazard events, and the consequences associated to an inadequate level of service of the infrastructure. Nevertheless, risk is not a stationary indicator, i.e. several parameters involved in the estimation of risk are time-dependent. One of them comprises the structural capacity of infrastructures, which is affected by deterioration effects over time. This gradual deterioration can be regarded as an interceptable hazard, which may act simultaneously with other non-interceptable hazards such as natural events (e.g. earthquakes). Therefore, a risk assessment framework should account for the probability of having these multiple hazards acting during the service life of infrastructures. The aim of this paper is to conduct a risk assessment for a railway bridge subjected to a multi-hazard scenario, i.e. an observable interceptable hazard corresponding to chloride induced corrosion of the reinforcing steel in reinforced concrete elements, together with seismic hazard. The results of the study demonstrate the relevance of considering time-dependent deterioration effects on the risk assessment of bridges, as the increase in the seismic fragility over time is significant. These findings are relevant for decision-making to plan and execute optimal interventions., FCT -Fundação para a Ciência e a Tecnologia(PEst-C/ECI/UI4029/2011 FCOM-01–0124-FEDER-022681)