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Steel fibres for the shear resistance of high strength concrete beams   

Available research on the use of steel fibres to increase the shear resistance of concrete structures shows that the effectiveness of this type of reinforcement increases with the increase of the concrete compressive strength, as long as the fibre rupture is avoided. Experimental research has also indicated that the effectiveness of the fibre reinforcement for the shear resistance is more pronounced in shallow beams than in deep beams. In terms of analytical research, some models have been proposed and, recently, RILEM TC 162 TDF recommended an analytical approach for the...

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CFRP group effect and interaction between stirrups and strips on the NSM-shear strengthening of RC beams   

Available experimental research shows that the technique based on installing Carbon Fibre Reinforced Polymer (CFRP) strips into slits opened on the cover concrete of the beam’s lateral faces, designated as Near Surface Mounted (NSM), is very effective to increase the shear resistance of reinforced concrete (RC) beams. However, recent research has revealed that, in terms of NSM shear strengthening effectiveness, a detrimental effect can occur between existing steel stirrups and applied strips, as well as amongst the strips when the distance between strips, sf, is...

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Aplicação de novos materiais e de modelos de análise não linear material no desenvolvimento de sistemas estruturais pré-fabricados para edifícios industriais   

No presente trabalho é descrita a investigação efectuada no âmbito do dimensionamento de viga pré-fabricada para vencer vãos de 20 m de coberturas de edifícios industriais, denominada VMC20. Para tal utilizou-se betão reforçado com fibras de aço e recorreu-se a métodos avançados de análise de estruturas. João Dias, Lúcio Lourenço, Delfina Gonçalves, Francisco Oliveira....

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Painéis pré-fabricados em betão autocompactável reforçado com fibras de aço para fachadas de edifícios   

No âmbito de um projecto de investigação envolvendo as Empresas Prégaia e Civitest e a Universidade do Minho, foi desenvolvido um betão autocompactável reforçado com fibras de aço com propriedades apropriadas para a pré-fabricação de painéis de fachada de edifícios. Em paralelo foi desenvolvida investigação numérica no sentido de simular o comportamento até à rotura deste tipo de elementos estruturais. Neste trabalho resume-se a investigação experimental e numérica desenvolvida no âmbito deste projecto.Delfina Gonçalves, João Dias, Lúcio Lourenço, Joaquim Barros, Carlos...

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Flexural behaviour of steel fibre reinforced self-compacting concrete laminar structures   

A high strength Steel Fibre Reinforced Self-Compacting Concrete (SFRSCC) of high ductility was developed. To evaluate the contribution of steel fibre reinforcement for the flexural resistance of laminar structures, an experimental program was carried out with slab strips of distinct longitudinal reinforcement ratio ( sl ρ ), submitted to four point loads. A total of twelve slab strips were tested, grouped in three series of distinct sl ρ (0.2, 0.36 and 0.56). Each series is composed of four slab strips, two of them without fibre reinforcement, and the other two with...

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Behaviour of a fibre reinforced concrete tunnel segment submitted to fire   

Four concrete tunnel lining specimens were manufactured by a developed Fibre Reinforced Concrete of Enhanced Fire Resistance (FRCEFR) in order to assess the possibilities of steel fibres as an alternative reinforcement system for this type of structural application. For this purpose, the specimens were subjected to fire and flexural load conditions, and the obtained main results are presented and analyzed. A test program to evaluate the influence of the compressive stress level and maximum temperature on the concrete compressive strength was also conducted, and the...

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Total registos: 62
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