39 documents found, page 1 of 4
Durability of bond in NSM CFRP-concrete systems under different environmental c...
Fernandes, Pedro Miguel Gomes; Sena-Cruz, José; Xavier, José; Silva, Patrícia Moreira; Pereira, E. N. B.; Cruz, José Ricardo LoureiroThis paper addresses the durability of bond between concrete and carbon fibre reinforced polymer (CFRP) strips installed according to the near-surface mounted (NSM) technique (NSM CFRP-concrete systems) under the effects of two main groups of environmental conditions: (i) laboratory-based ageing conditions; (ii) real outdoor ageing conditions. The bond degradation was evaluated by carrying out direct pullout te...
Recent contributions from UMinho and Empa on durability issues of flexural stre...
Sena-Cruz, José; Michels, Julien; Correia, Luís Luciano Gouveia; Harmanci, Yunus; Silva, Patrícia Moreira; Gallego, Julio; Fernandes, Pedro Miguel GomesCommon research activities in the field of durability of prestressed externally bonded reinforcement (EBR) for reinforced concrete (RC) structures were carried out at both the University of Minho (UMinho) and the Swiss Federal Laboratories for Materials Science and Technology (Empa). The research includes the study of the durability of (i) the constituent materials (concrete, epoxy and CFRP laminate) and (ii) l...
Bond behavior of EBR CFRP systems in concrete: influence of surface preparation
Soares, Sérgio Ricardo Reis; Cruz, José Ricardo Loureiro; Fernandes, Pedro Miguel Gomes; Sena-Cruz, JoséThe EBR strengthening technique has been used to improve existing reinforced concrete (RC) structures. In many cases CFRP laminates are used as reinforcing material, whereas epoxy adhesives are used as the bonding agent. In the last decades several investigations have been carried out in order to predict the bond strength of EBR CFRP systems in concrete and, as consequence of that, many analytical expressions c...
Effects of different environmental conditions on the mechanical characteristics...
Silva, Patrícia Moreira; Fernandes, Pedro Miguel Gomes; Sena-Cruz, José; Xavier, José; Castro, Fernando; Soares, Delfim; Carneiro, Vítor Hugo PimentaWith the aim of characterising a commercially available epoxy adhesive used for fibre-reinforced polymers strengthening applications, when submitted to different environmental conditions, mainly thermal (TC), freeze-thaw (FT), and wet-dry (WD) cycles and immersion in pure (PW) and water with chlorides (CW) for periods of exposure that lasted up to 16 months, an experimental program was carried out. Several meth...
Durabilidade da ligação entre o betão e laminados de CFRP aplicados de acordo c...
Fernandes, Pedro Miguel Gomes; Sena-Cruz, José; Xavier, José; Silva, Patrícia Moreira; Soares, SérgioNos últimos anos, considerável investigação tem sido desenvolvida no reforço de estruturas de betão armado com a técnica NSM. Esta técnica consiste na introdução de laminados ou varões de FRP em ranhuras pré-executadas no betão de recobrimento do elemento a reforçar. Normalmente, são utilizados adesivos epoxídicos na ligação entre FRP e betão O presente trabalho procura contribuir para o conhecimento da durabil...
Influence of temperature on the curing of an epoxy adhesive and its influence o...
Benedetti, Andrea; Fernandes, Pedro Miguel Gomes; Granja, José Luís Duarte; Sena-Cruz, José; Azenha, MiguelIn NSM-CFRP installations, the mechanical behaviour of the strengthening system is strongly influenced by the epoxy adhesive, particularly at early ages. In the present work, the influence of temperature on the curing process of the epoxy was investigated. Three distinct temperatures were studied: 20, 30 and 40 °C. The elastic modulus of the adhesive was monitored through EMM-ARM (Elasticity Modulus Monitoring ...
Bond on NSM CFRP systems: recent contributions of UMinho on durability, quality...
Sena-Cruz, José; Fernandes, Pedro Miguel Gomes; Coelho, Mário Rui Freitas; Silva, Patrícia Moreira; Granja, José Luís Duarte; Benedetti, AndreaIn the last years, significant research in the context of bond of near-surface mounted (NSM) fibre reinforced polymer (FRP) systems in concrete has been conducted at the Department of Civil Engineering of the University of Minho. This paper presents a brief summary of the major results obtained in that research, namely in terms of durability, quality control and design topics. Accelerated ageing tests on NSM FR...
Comportamento da aderência de sistema de reforço NSM-CFRP na presença de difere...
Cruz, José Ricardo; Borojevic, Anja; Sena-Cruz, José; Pereira, E. N. B.; Fernandes, Pedro Miguel Gomes; Silva, Patrícia Moreira; Kwiecien, ArkadiuszNo contexto atual, o reforço de estruturas de betão armado assume uma importância cada vez maior devido a diversos fatores. A técnica de reforço de estruturas de betão armado que utiliza laminados de CFRP inseridos no betão de recobrimento (designada por NSM – Near Surface Mounted na literatura inglesa) tem vindo a ser alvo de vários estudos dadas as suas potencialidades. No entanto, o estudo da influência do t...
Influência do tipo de adesivo no comportamento à flexão de faixas de laje refor...
Cruz, José Ricardo; Borojevic, Anja; Sena-Cruz, José; Silva, Patrícia Moreira; Fernandes, Pedro Miguel Gomes; Kwiecien, ArkadiuszAtualmente verifica-se que muitas das estruturas de betão armado existentes apresentam necessidade de reparação/reforço estrutural devido a diferentes fatores, tais como a degradação dos seus materiais constituintes e a necessidade de uma capacidade resistente superior. O recurso à técnica NSM (Near Surface Mounted na literatura inglesa), baseada na introdução dos laminados de CFRP no betão de recobrimento, é u...
Bond behaviour of NSM CFRP-concrete systems: durability and quality control
Fernandes, Pedro Miguel GomesOver the last two decades, the near-surface mounted (NSM) strengthening technique using fibre reinforced polymers (FRP) has been adopted to increase the load carrying capacity of reinforced concrete (RC) members, mainly in bending and shear. This technique consists on inserting the FRP material in pre-cut grooves opened in the concrete cover of the elements to be strengthened. The FRP reinforcement is bonded to...