Estudo da aderência entre concreto e armadura: análise da influência das fibras de aço

• Autor(a) principal: DANIN, Alice Ribeiro
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tde/1328
• topic: Concreto; Fibras de aço; Aderência; 1.Concreto 2.Fibras de aço 3.Aderência; Concrete; Steel fibers; Bond; CNPQ::ENGENHARIAS::ENGENHARIA CIVIL::CONSTRUCAO CIVIL

Bond between steel bars and concrete allows the use of reinforced concrete as a construction material. If the bond is appropriate, the cracks will be as little as possible, so the reinforcing bar will be protected by the surrounded concrete. Therefore, the aim of this research was to analyse the influence of steel fiber on mechanical properties of concrete and on bond strength. To this end, forty eight pull-out tests had been performed. A single test‟ bar was cast into the centre of a specimen, which measured 300 mm × 200 mm × 150 mm. It had been used four bars diameters: 10 mm, 12,5 mm, 16 mm and 20 mm. The test bars were pulled out of the concrete block using a 300 kN capacity universal testing machine (UTM) operated in displacement control. The tests were performed varying the length of mounting bar tested (for five and ten times the diameter) and the presence of steel fibers. The fiber content, as in volume, ranged from 0%, 1% and 2%. It was used coarse aggregate with maximum size of 12,5 mm and concrete with target compressive strength of 60 MPa at 28 days. It was previously characterized by tests of compressive strength, modulus of elasticity, tensile strength and diametrical compression strength with displacement control. For the concrete without fibers, it was determinate the fracture energy, and for the ones with steel fiber reinforcement the toughness was determinate. There were used short steel hooked fibers, which were 35 mm long. The tests determined the bond stress in the bar in each of the specimens, which concludes that the addition of fiber in the proposed amount had just a little influence on the results of the pull-out tests for the 10 mm diameter specimens.