Encontrados 122 documentos, a visualizar página 1 de 13
Flexural strengthening of RC slabs with prestressed CFRP strips : serviceabilit...
Sena-Cruz, José; Correia, Luís; Teixeira, Tiago; Michels, JulienO presente trabalho pretende contribuir para o conhecimento da técnica EBR (Externally Bonded Reinforcement) usando laminados de CFRP (Carbon Fiber-Reinforced Polymer) pré-esforçados no reforço à flexão de estruturas de betão, sob condições de serviço (SLS) e estado limite último (ULS). Para tal, foi desenvolvido um programa experimental composto por 8 lajes ensaiadas até à rotura. Duas lajes foram usadas como ...
Comportamento à fadiga de elementos de betão reforçados através de sistemas NSM...
Fernandes, Pedro Miguel Gomes; Silva, Patrícia; Sena-Cruz, José; Azenha, Miguel; Barros, Joaquim A. O.O presente trabalho tem como objetivo principal contribuir para o conhecimento do comportamento a longo prazo de estruturas de betão reforçadas de acordo com a técnica NSM (Near-Surface Mounted). O comportamento a longo prazo das estruturas reforçadas é afetado pelas condições ambientais, tais como gelo/degelo, ciclos térmicos, exposição a agentes químicos agressivos e radiação ultra violeta. Além disso, o comp...
Luiz Bandeira bridge : assessment of a historical rc bridge
Sena-Cruz, José; Ferreira, Rui Miguel; Ramos, Luís F.; Fernandes, Francisco; Miranda, F.; Castro, F.The Luiz Bandeira Bridge is located along the Portuguese national road EN333-3, breaching the valley of the Vouga River, just northeast of the small village Sejães, in the district of Oliveira de Frades. It is considered to be the oldest concrete bridge in use in Portugal, and one of the oldest in Europe. Since this bridge is at risk of disappearing due to a construction of a dam, the Department of Civil Engine...
Evaluation of code formulations for NSM CFRP bond strength of RC elements
Coelho, Mário R. F.; Sena-Cruz, José; Dias, Salvador J. E.; Miranda, Tiago F. S.This paper presents an analytical analysis which intends to verify the accuracy of existing code formulations for predicting the pullout strength of NSM CFRP systems applied to concrete. A database with a limited set of parameters was gathered and two code formulations were tested on it. Then, a new approach was tested. This uses Data Mining algorithms to develop models to predict the pullout strength based on ...
Flexural response of HSC girders strengthened with non- and prestressed CFRP la...
Fernandes, P.; Sena-Cruz, José; Fernandes, C.; Silva, Patrícia; Costa, Daniel Dias da; Júlio, EduardoAn experimental programme was carried out to characterise the flexural response of prestressed highstrength concrete (HSC) girders strengthened with CFRP laminates. For that purpose, four beams with 20 m span were subjected to four-point bending loads and the effectiveness of two distinct strengthening strategies was analysed. The following testing situations have been considered: one girder was externally stre...
Creep behavior of concrete elements strengthened with NSM CFRP laminate strips ...
Sena-Cruz, José; Silva, Patrícia; Fernandes, Pedro Miguel Gomes; Azenha, Miguel; Barros, Joaquim A. O.; Sousa, Christoph; Castro, FernandoThe present work intends to contribute for the knowledge on the long-term deformational performance of concrete structures strengthened with the near-surface mounted (NSM) technique. For that purpose a wide experimental program has been initiated using beam pullout and slab specimens submitted to sustained loads under the following environmental conditions: (i) 20ºC temperature and 55% relative humidity; (ii) i...
Influence of fatigue loading and environmental conditions on the bond behavior ...
Mendes, Pedro J. D.; Barros, Joaquim A. O.; Sena-Cruz, José; Taheri, MahsaTo assess the influence of fatigue loading and environmental conditions on the bond behavior between glass fiber reinforced polymer (GFRP) systems and steel fiber reinforced self-compacting concrete (SFRSCC) that are adhesively bonded, an experimental program composed of push-out tests was carried out. The following three scenarios were selected for the environmental conditions: natural conditions; wet-dry cycl...
Shear capacity of HPFRC beams flexurally reinforced with steel and prestressed ...
Soltanzadeh, Fatemeh; Mazaheripour, H.; Barros, Joaquim A. O.; Sena-Cruz, JoséThis paper presents the relevant results from an experimental program to assess the shear capacity of high performance fiber reinforced concrete (HPFRC) beams flexurally reinforced with a hybrid system of passive steel and prestressed GFRP longitudinal bars. Three series of two beams with different level of prestressing were tested. The effect of prestressing level on the shear capacity of the beams was the mai...
Bond between glulam and NSM CFRP laminates
Sena-Cruz, José; Jorge, Marco; Branco, Jorge M.; Cunha, Vitor M. C. F.With the aim of evaluating the bond behaviour between glulam and carbon fibre reinforced polymer laminates strips, an experimental program using pull-out tests was carried, when the near-surface strengthening technique is applied. Two main variables were studied: the bond length and the type of pull-out test configuration. The instrumentation included the loaded and free-end slips, as well as the pull-out force...
Back analysis of geomechanical parameters in underground works using an evoluti...
Moreira, Nuno Ricardo Vilaça; Miranda, Tiago F. S.; Pinheiro, Marisa da Mota; Fernandes, Pedro Miguel Gomes; Dias, Daniel; Costa, L.; Sena-Cruz, JoséThe purpose of this work is to evaluate the performance of an optimization algorithm from the field of evolutionary computation, namely an Evolution Strategy, in back analysis of geomechanical parameters in underground structures. This analysis was carried out through a parametric study of a synthetic case of a tunnel construction. Different combinations of parameters and measurements were carried out to test t...
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