Self-monitoring composite rods for sustainable construction

This paper presents the development and properties assessment of braided reinforced composite rods (BCR) able to both reinforce and monitor the stress state of concrete infrastructures. The research study aims at understanding the tensile behaviour and self-monitoring ability of composite rods reinforced by a textile structure – braided structure with core reinforcement – for civil engineering applications, namely for concrete internal reinforcement, as a steel substitute, in order to improve structures safety and sustainability. Seven types of braided composite rods have been produced using an author patented technique based on a modified conventional braiding machine. The tensile properties of the braided reinforced composite rods were evaluated in order to identify the type(s) of fibre(s) to be used as core reinforcement. BCR have been tested under bending while the variation of the electrical resistance was simultaneously monitored

Fibrous based materials in sustainable civil and architectural applications – a review

The aim of this review paper is to present a survey on fibrous materials used in key areas of construction and architectural sectors. Here are highlighted conceptual challenges involved in some of the applications trying to define what we call a “green” building. The main applications reviewed are concrete reinforcement, structural health monitoring, insulation, and architectural membranes. On the other hand, tendencies in the area such as sustainability, weight reduction, enhanced durability and resistance, multi-functionality, bio-mimetization and hybridization are also discussed and analysed

Timber-concrete composite bridges: Three case studies

During the last years, timber-concrete composite (TCC) structures have been extensively used in Europe both in new and existing buildings. Generally speaking, a composite structure combines the advantages of both materials employed: the strength and stiffness of the concrete in compression and the tensile strength, lightweight, low embodied energy, and aesthetical appearance of the timber. The concrete slab provides protection of the timber beams from direct contact with water, which is crucial to ensure the durability of the timber beams, particularly when used for bridges. Different types of connectors can be used to provide force exchange between the concrete slab and the timber beam. The choice of a structurally effective yet cheap shear connection between the concrete topping and the timber joist is crucial to make the TCC structures a viable solution that can compete with reinforced concrete and steel structures. In this paper, the possibilities offered by TCC structures for short-span bridge decks are discussed. The technology of TCC structures and the general design rules are illustrated. Three case studies are reported, including a short-span bridge tested in Colorado, USA, with the timber layer being constructed from recycled utility poles and notch connection; a TCC bridge with glulam beams and triangular notches with epoxy-glued rebar connectors built in Portugal; and a TCC bridge with glulam beams and rectangular notches built in Germany. All the solutions were found to be structurally effective and aesthetically pleasing. They can all provide a sustainable option for short-span bridges. Keywords: Timber-concrete composite, Bridge, Design, Connection syste

Assessment of GFRP bond behaviour for the design of sustainable reinforced seawater concrete structures

Freshwater is an increasingly scarce resource. Its use in the production of concrete is one important contributor to its fast depletion. Alternatively, the use of seawater for reinforced concrete production, combined with the use of glass fibre reinforced polymers (GFRP) as reinforcement, may represent an interesting solution to increase concrete sustainability. The objective of this paper is to explore this promising solution through the development of concrete compositions with seawater. Additionally, it is also an objective to assess the bond behaviour between GFRP rods and concrete, in a design perspective. The influence of concrete age, rod diameter and anchorage length were also investigated. An analytical model capable of determining the local bond stress-slip laws was used. Results demonstrated that the use of seawater had no relevant effects on neither concrete mechanical properties nor bond behaviour.The study presented in this paper is a part of the research project “NEXT-SEA: Next Generation Monitoring of Coastal Systems in a Scenario of Global Change”, financed by CCDRN and FEDER funds in the scope of the Next-sea project (NORTE-01-0145-FEDER-000032). The authors acknowledge all the companies that have been involved supporting and contributing for the development of this study, mainly: S&P Clever Reinforcement Ibérica Lda., Burgoparaíso – Unipessoal Lda., Secil, Sika Portugal – Produtos Construção e Indústria S.A. The first and the last authors wishes also to acknowledge the grants SFRH/BD/131913/2017 and SFRH/BSAB/150266/2019, respectively, provided by FCT, financed by European Social Fund and by national funds through the FCT/MCTES

Design and experimentation of a solar power system powering measurement chains in concrete structures strengthened with fiber-reinforced polymer rebars

Aquest treball de fi de grau té com a objectiu explorar la viabilitat d'utilitzar plaques solars per alimentar cadenes de mesura en estructures de formigó enfortides amb barres de polímer reforçat amb fibra (FRP). Els principals objectius són: dur a terme una investigació profunda per entendre el funcionament de cada element que conforma el sistema, valorar diverses alternatives, identificar aspectes a tenir en compte respecte a la configuració del model, dissenyar un sistema d'energia solar a mida i realitzar-hi proves experimentals. L'experiment implica una prova de flexió de 3 punts, on la barra de FRP s’ha sotmès a diferents condicions de càrrega. La mesura de la tensió ha sigut l'objectiu principal, tenint en compte la seva sensibilitat a la temperatura, factors ambientals i variacions de càrrega. La prova revela diferències entre la suspensió de càrrega directa i les suspensions seqüencials, destacant l'impacte de la magnitud de la càrrega, la distribució i la resposta estructural en els valors de deformació. Els resultats han demostrat l'eficàcia dels panells solars per proporcionar energia sostenible per a les cadenes de mesura. L'anàlisi d'alternatives mostra el potencial de l'energia solar en aquests tipus de muntatges i com a conseqüència la possible contribució al desenvolupament sostenible dels sistemes de mesura en el sector de la construccióEste trabajo de fin de grado tiene como objetivo explorar la viabilidad de utilizar placas solares para alimentar cadenas de medida en estructuras de hormigón fortalecidas con barras de polímero reforzado con fibra (FRP). Los principales objetivos son: llevar a cabo una investigación profunda para entender el funcionamiento de cada elemento que conforma el sistema, valorar diversas alternativas, identificar aspectos a tener en cuenta respecto a la configuración del modelo, diseñar un sistema de energía solar a medida y realizar pruebas experimentales. El experimento implica una prueba de flexión de 3 puntos, donde la barra de FRP se ha sometido a distintas condiciones de carga. La medida de la tensión ha sido el principal objetivo, teniendo en cuenta su sensibilidad a la temperatura, factores ambientales y variaciones de carga. La prueba revela diferencias entre una suspensión de carga directa y suspensiones secuenciales, destacando el impacto de la magnitud de la carga, distribución y respuesta estructural en los valores de deformación. Los resultados han demostrado la eficacia de los paneles solares para proporcionar energía sostenible a las cadenas de medida. El análisis de alternativas muestra el potencial de la energía solar en este tipo de montajes y como consecuencia de la posible contribución al desarrollo sostenible de los sistemas de medida en el sector de la construcciónThis final project aims to explore the viability of using solar panels for powering measurement chains in concrete structures reinforced with fiber-reinforced polymer bars (FRP). The main objectives of the thesis are to carry out in-depth research to understand the operation of each element that makes up the system, assess various alternatives, identify aspects to take into account regarding the configuration of the model, design a custom solar energy system and carry out experimental tests. The experiment involves a 3-point bending test, where the FRP rebar has been subjected to different load conditions. The strain measurement has been the primary focus, considering its sensitivity to temperature, environmental factors, and load variations. The test reveals differences between a direct load suspension and sequential suspensions, highlighting the impact of load magnitude, distribution, and structural response on strain values. The results have demonstrated the effectiveness of solar panels in providing sustainable energy for measurement chains. The analysis of alternatives shows the potential of solar energy in this type of set ups and therefore the possible contribution to the sustainable development of measurement systems in the construction secto

A review of intrinsic self-sensing cementitious composites and prospects for their application in transport infrastructures

Monitoring of transport infrastructures, in terms of early damage detection, can prevent the loss of life and economic damage associated with sudden infrastructure collapse and inform timely intervention, such as repair, to increase the sustainability and service life of infrastructures. Self-sensing cementitious geocomposites with the ability to detect stress, strain, and damage based on a piezoresistive mechanism enable the development of more integrated and viable geomaterial monitoring solutions than existing monitoring technologies. Self-sensing cementitious geocomposites are composed of conductive phases embedded in cementitious geomaterials that exhibit both sensing ability and superior mechanical properties. The states of stress, strain, displacement, and damage in infrastructures can be investigated by analysing the change in their electrical resistance. In this review, different types of self-sensing composites, their preparation, influential parameters, and associated theoretical investigations are discussed in detail to inform future advances in the development of self-sensing geocomposites. The challenges of this technology have also been summarised. This review is expected to stimulate and inform research that explores the development and application prospects of self-sensing cementitious geocomposites.This work was supported by the European Commission-Shiff2Rail Program under the project “IN2TRACK2–826255-H2020-S2RJU-2018/H2020-S2RJU CFM-2018”. It is also partly financed by FCT/MCTES through national funds (PIDDAC), under the R&D Unit of the Institute for Sustainability and Innovation in Engineering Structures (ISISE; reference UIDB/04029/2020), as well as under the R&D Unit of the Centre for Textile Science and Technology (2C2T)

Frontiers of Adaptive Design, Synthetic Biology and Growing Skins for Ephemeral Hybrid Structures

The history of membranes is one of adaptation, from the development in living organisms to man-made versions, with a great variety of uses in temporary design: clothing, building, packaging, etc. Being versatile and simple to integrate, membranes have a strong sustainability potential, through an essential use of material resources and multifunctional design, representing one of the purest cases where “design follows function.” The introduction of new engineered materials and techniques, combined with a growing interest for Nature-inspired technologies are progressively merging man-made artifacts and biological processes with a high potential for innovation. This chapter introduces, through a number of examples, the broad variety of hybrid membranes in the contest of experimental Design, Art and Architecture, categorized following two different stages of biology-inspired approach with the aim of identifying potential developments. Biomimicry, is founded on the adoption of practices from nature in architecture though imitation: solutions are observed on a morphological, structural or procedural level and copied to design everything from nanoscale materials to building technologies. Synthetic biology relies on hybrid procedures mixing natural and synthetic materials and processes

FINITE ELEMENT SIMULATION ANALYSIS OF STEEL TRUSS ARCH BRIDGE JACKING CONSTRUCTION

In this study, a spatial model of a steel truss arch bridge was established using the finite element software Midas/Civil to simulate and analyze the jacking construction process. The stress performance of the guide beam and main structure at each jacking stage was obtained. The results showed that in the first stage of jacking, the maximum stress and deflection values of the main girder were observed. The maximum stress on the upper edge of the main girder was 34.9MPa, and on the lower edge, it was -60.4MPa. The maximum deflection was -35.88mm. The maximum stress in the guide beam occurred during the jacking process and was -53.2MPa, corresponding to the cross-section at the root of the guide beam. The maximum deflection of the guide beam occurred in the maximum cantilever state and was -30.79mm. During the arch rib jacking process, the maximum stress was -49.4MPa. Both the maximum stress and deflection values were within the allowable range, indicating that the structure was in a safe state. This study provides a reference for similar bridge jacking construction projects

Fibre-reinforced polymers in reinforced and prestressed concrete applications: moving forward

Recent developments in the use of fibre-reinforced polymers (FRPs) in reinforced and prestressed concrete applications are reviewed. The influence of FRP material properties on the design of concrete structures is considered and applications are discussed in conjunction with the structural function of the FRP reinforcement. The review includes examples of the practical implementation of the technology and addresses important durability issues. A number of future considerations/research needs are identified and the requirement for the provision of standard, sustainable and cost-effective FRP solutions is highlighted. It is concluded that although there have been significant advances in our knowledge of the behaviour of FRP-concrete structures, the timeframe in which FRPs will no longer be considered as new materials remains ambiguous