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Reliability assessment of braided BFRP reinforcement for concrete structures

2017-05-25, Antonopoulou, Sofia, McNally, Ciaran

In recent years the long term durability of reinforced concrete structures has become a major concern. The effect of harsh loading conditions and aggressive environmental factors can lead to corrosion of reinforcing steel in civil engineering applications. This in turn leads to undesired repairs, additional costs and shorter service lives. Advanced composite materials, such as Basalt Fibre Reinforced Polymer (BFRP), have the capacity to significantly address this problem. These materials have enhanced physical properties such as higher mechanical and corrosion resistance, and have the potential to replace traditional steel rebars as tension reinforcement in concrete. There are however limitations that prevent their use on a larger scale, and lack of ductility is the most significant. Braiding techniques could provide the required performance benefits related to the additional ductility and flexibility needed, as well as enhancing the bond between FRP and concrete. If this is achieved, it has the potential to prevent a brittle failure and successfully meet strength, reliability and cost demands. This study focuses on the basics of materials characterization and reliability analysis of internal BFRP reinforcement for concrete structures towards design optimization for structural reliability over their service life. 

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TRUSS, a European Innovative Training Network Dealing with the Challenges of an Aging Infrastructure Network

2019-04-01, González, Arturo, Barrias, Antonio, Teixeira, Rui, Martinez, Daniel, Heitner, Barbara, Antonopoulou, Sofia, Zou, Guang, Gonzalez Merino, Alberto, Sourav, Shah Nur Alam, Casas, Joan Ramon, O'Connor, Alan, Nogal, Maria, O'Brien, Eugene J., Yalamas, Thierry, McNally, Ciaran, Banisoleiman, Kian, Costas de la Peña, Luis, Al-Sabah, Salam

Inspections and maintenance of infrastructure are expensive. In some cases, overdue or insufficient maintenance/monitoring can lead to an unacceptable risk of collapse and to a tragic failure as the Morandi bridge in Genoa, Italy, on 14th August 2018. An accurate assessment of the safety of a structure is a difficult task due to uncertainties associated with the aging and response of the structure, with the operational and environmental loads, and with their interaction. During the period from 2015 to 2019, the project TRUSS (Training in Reducing Uncertainty in Structural Safety) ITN (Innovative Training Network), funded by the EU H2020 Marie Curie-Skłodowska Action (MSCA) programme, has worked towards improving the structural assessment of buildings, energy, marine, and transport infrastructure. Fourteen Early Stage Researchers (ESRs) have been recruited to carry out related research on new materials, testing methods, improved and more efficient modelling methods and management strategies, and sensor and algorithm development for Structural Health Monitoring (SHM) purposes. This research has been enhanced by an advanced program of scientific and professional training delivered via a collaboration between 6 Universities, 1 research institute and 11 companies from 5 European countries. The high proportion of companies participating in TRUSS ITN has ensured significant industry expertise and has introduced a diverse range of perspectives to the consortium on the activities necessary to do business in the structural safety sector.

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Contributions by Marie Sklodowska-Curie TRUSS-ITN towards reducing uncertainty in structural safety of buildings, roads, energy and marine infrastructure

2018-04-11, González, Arturo, Perrotta, Federico, Milana, Giulia, Sourav, Shah Nur Alam, Antonopoulou, Sofia, McNally, Ciaran, et al.

There is multitude of models available to assess structural safety based on a set of input parameters. As the degree of complexity of the models increases, the uncertainty of their output tends to decrease. However, more complex models typically require more input parameters, which may contain a higher degree of uncertainty. Therefore, it becomes necessary to find the balance that, for a particular scenario, will reduce the overall uncertainty (model + parameters) in structural safety. The latter is the objective of the Marie Sklodowska-Curie Innovative Training Network titled TRUSS (Training in Reducing Uncertainty in Structural Safety) funded by the EU Horizon 2020 research and innovation programme (http://trussitn.eu). This paper describes how TRUSS addresses uncertainty in: (a)  structural reliability of materials such as basalt fiber reinforced polymer, (b) testing techniques in the assessment of concrete strength in buildings, (c) numerical methods in computing the non-linear response of submerged nuclear components subjected to an earthquake, (d) estimation of life of wind turbines, (e) the optimal inspection times and management strategies for ships, (f) characterization of the dynamic response of ship unloaders and (g) the relationship between vehicles fuel consumption and pavement condition. 

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Developing braided FRP reinforcement for concrete structures

2016-08-30, Antonopoulou, Sofia, McNally, Ciaran, Byrne, Greg

In recent years, significant research has been conducted, by both industry and academia, into the optimum development and use of Fibre Reinforced Polymer composite materials in infrastructure. In particular, it is widely recognised that FRPs have the potential to replace conventional internal steel rebars in concrete reinforcement and offer performance benefits related to their advanced properties, such as corrosion resistance, high tensile strength etc.A review of the available literature indicates that brittle behaviour of FRP can significantly decrease the expected ultimate load capacity and, thus have a negative effect on structure¿s long term durability. However, selecting braiding as manufacture technique and enhancing flexural capacity and shear strength through additional helical reinforcement, could provide structure with the additional ductility needed to prevent a brittle failure. Furthermore, the impact of deterioration mechanisms, focusing on the interaction between FRP and concrete in a structure, is an aspect for further investigation via laboratory testing and advanced analysis.This study summarises the results of research on structural design and manufacture methods of FRP composite materials by presenting new configuration and types of FRP reinforcement in order to encourage the use of these promising materials in construction industry.

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A comparative study on different BFRP rebar design methodologies

2018-08-30, Antonopoulou, Sofia, McNally, Ciaran, Byrne, Greg

This study compares the physical properties and tensile behaviour of two different basalt fibre reinforced polymer (BFRP) rebar designs. Both types are developed using basalt fibres and epoxy resin as reinforcement and matrix respectively; composites with a constant cross section of 8 mm diameter are manufactured using a vacuum assisted resin infusion technique. The first configuration consists of eight braided layers at various angles, while the second one combines a unidirectional core with four outer braided layers. The latter hybrid design is introduced to improve the elastic modulus of braided BFRP reinforcement used in concrete structures. Tensile performance of all BFRP rebars produced in UCD laboratory is numerically and experimentally evaluated, and results for both approaches are compared. The effective longitudinal in-plane modulus and the fibre volume fractions (φf) of each sample is calculated using the classical laminate theory and then, tensile tests are performed in accordance to the B2_ACI 440.3R-04 standard to experimentally validate the numerical results. Initial findings indicate that the elastic modulus of BFRP rebar can be enhanced by combining braiding with a unidirectional fibre core while a sufficient tensile strength is obtained, but additional research towards an optimal hybrid design is required.

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Development of Braided Basalt FRP Rebar for Reinforcement of Concrete Structures

2016-12-16, Antonopoulou, Sofia, McNally, Ciaran, Byrne, Greg

In recent years, the development and use of Fibre Reinforced Polymer composite materials in infrastructure have gained increasing attention worldwide. More specifically, natural mineral fibres such as basalt are currently being developed and are showing promising properties. Within an appropriate polymer matrix, their use as reinforcement in concrete structures offers performance benefits related to their environmentally friendly and non-corrodible nature. In particular, BFRPs have the potential to replace conventional internal steel rebar and thus, to be the next generation material in concrete reinforcement applications. A detailed literature review indicates that a careful selection of the appropriate manufacture technique and design methodology are required in order to prevent brittle failure on a concrete structure reinforced with FRP composite material. This paper reports on how to use the additional helical reinforcement and the braid configuration in order to increase strength, structural ductility and long term durability. Moreover, this study outlines the development of an analytical numerical model to predict the longitudinal elastic modulus of braided composites, as well as its validation by comparison of the results with available data from the literature.

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TRUSS Training in Reducing Uncertainty in Structural Safety: D4.2 Final Report: WP4 -Building, Energy, and Marine Infrastructure

2019-02-28, González, Arturo, McNally, Ciaran, Antonopoulou, Sofia, et al.

The EU TRUSS (Training in Reducing Uncertainty in Structural Safety, 2015-2018) ITN (Innovative Training Network) project features 14 Early Stage Researchers (ESRs), each of whom has conducted 3 years of Ph.D. level research on key issues relating to structural reliability (http://trussitn.eu/). Six of these researchers have worked on research topics that fall into WP4: Buildings, Energy and Marine Infrastructure. Although these applications are quite diverse, they are connected by virtue of the very aggressive environments that the infrastructure is subjected to. Some of these are corrosive, others are radioactive, and all display non-linear structural responses.

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Mechanical characterisation of braided BFRP rebars for internal concrete reinforcement

2018-10-10, Antonopoulou, Sofia, McNally, Ciaran, Byrne, Greg

This study investigates the tensile behaviour of basalt fibre reinforced polymer (BFRP) composites that were developed using braiding as a manufacturing technique. Those materials will be introduced in concrete reinforcement applications. Three BFRP rebar sizes with a circular constant cross section and different braided configurations are developed and characterised with respect to their internal architecture. The braid angle on each layer of the rebar, varying from 10◦ to 45◦, is an important parameter that has a direct impact on its performance characteristics. The effective longitudinal in-plane modulus (ExFRP) of each braided sample is calculated numerically using the classical laminate theory (CLT) approach and then, tensile tests are performed according to the relevant standard. Comparisons between analytical and experimental data demonstrate a significant influence of braiding parameters, like braiding angle and number of braiding layers, on the mechanical properties of BFRP rebars. In addition, it is noteworthy that all predicted moduli determined with CLT numerical approach are found to be higher than the test results and overestimate rebar’s stiffness, most probably due to the degree of undulation from braiding process.

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TRUSS Training in Reducing Uncertainty in Structural Safety: D2.5 Final Report: WP2 - Dissemination and Outreach

2019-02-28, González, Arturo, Casas, Joan Ramon, Ahern, Aoife, Martinez, Daniel, Laefer, Debra F., O'Brien, Eugene J., O'Sullivan, J. J., Manriquez, Loreto, Beizaei, Parisa, Purcell, Patrick J., Chen, Siyuan, Antonopoulou, Sofia, et al.

This report describes the outputs of work package WP2 (Dissemination and Outreach) from 1 st January 2015 to 31st December 2018. Dissemination by TRUSS is keenly aware of the importance of not only producing and presenting research outputs for the scientific community and key stakeholders (i.e., via conferences, workshops, publications and reports), but also engaging the general public in line with the Innovation Union objectives. TRUSS mainly deals with the challenges faced at the design, assessment and management stages of large scale structures. Outreach activities, blogs and social media and other communications by TRUSS, bring awareness to the public on the importance of this research on infrastructure to support a community, region or country, and also motivate School and University students to pursue a research career. These activities make citizens aware of: • Infrastructure aging and failing, with funding that has been insufficient to repair and replace it; • The important role of the Marie Skłodowksa-Curie Actions in forming 21st century engineers that will have the skills to face the formidable challenge of modernizing the fundamental infrastructure that support civilization.

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TRUSS, a European innovative training network dealing with the challenges of an aging infrastructure network

2018-11-12, González, Arturo, Barrias, Antonio, Teixeira, Rui, Martinez, Daniel, Heitner, Barbara, Antonopoulou, Sofia, Zou, Guang, Gonzalez Merino, Alberto, Sourav, Shah Nur Alam, Casas, Joan Ramon, O'Connor, Alan, Nogal, Maria, O'Brien, Eugene J., Yalamas, Thierry, McNally, Ciaran, Banisoleiman, Kian, Costas de la Peña, Luis, Al-Sabah, Salam

Inspections and maintenance of infrastructure are expensive. In some cases, overdue or insufficient maintenance/monitoring can lead to an unacceptable risk of collapse and to a tragic failure as the Morandi bridge in Genoa, Italy, on 14th August 2018. An accurate assessment of the safety of a structure is a difficult task due to uncertainties associated with the aging and response of the structure, with the operational and environmental loads, and with their interaction. During the period from 2015 to 2019, the project TRUSS (Training in Reducing Uncertainty in Structural Safety) ITN (Innovative Training Network), funded by the EU H2020 Marie Curie-Skłodowska Action (MSCA) programme, has worked towards improving the structural assessment of buildings, energy, marine, and transport infrastructure. Fourteen Early Stage Researchers (ESRs) have been recruited to carry out related research on new materials, testing methods, improved and more efficient modelling methods and management strategies, and sensor and algorithm development for Structural Health Monitoring (SHM) purposes. This research has been enhanced by an advanced program of scientific and professional training delivered via a collaboration between 6 Universities, 1 research institute and 11 companies from 5 European countries. The high proportion of companies participating in TRUSS ITN has ensured significant industry expertise and has introduced a diverse range of perspectives to the consortium on the activities necessary to do business in the structural safety sector.