EECA - Artigos publicados em periódicos
URI Permanente para esta coleção
Navegar
Navegando EECA - Artigos publicados em periódicos por Assunto "Aderência"
Agora exibindo 1 - 2 de 2
Resultados por página
Opções de Ordenação
Item Influência da adição de fibras de aço na tensão de aderência de barras de aço retilíneas(2013-04) Araújo, Daniel de Lima; Danin, Alice Ribeiro; Melo, Matilde Batista; Rodrigues, P. F.Bonding between steel bars and concrete makes the two materials compatible, enabling the use of reinforced concrete as a construction material. If the bond is good, there will be less cracks, and the reinforcing bar will be better protected by the surrounded concrete. The aim of this research was to analyze the influence of steel fibers on concrete-steel bond strength. Therefore, pull-out tests were performed with thirty-three prismatic specimens measuring 200 mm x 300 mm x 150 mm. The variables analyzed were: bar diameter (10 mm, 12.5 mm, 16 mm and 20 mm); bond length (five and ten times the diameter); and the volume of steel fibers added to the concrete (1% and 2%). Short, steel, hooked fibers were used, 35 mm in length and with aspect ratio of 65. Based on the pull-out tests assays, the form and force of the rupture was determined in each specimen, Computational simulations of the specimens were also performed with bars of 100 mm in diameter. Both the results of the experimental tests and the modeling showed that the addition of fibers had little effect on the bond strength between the bar and the concrete. On the other hand, when the bond rupture occurred by splitting of the concrete cover, the influence of the steel fibers was significant.Item Influência dos parâmetros de ensaio na determinação da resistência de aderência de revestimentos de argamassa(2009-12) Costa, Eliane Betânia Carvalho; Carasek, HelenaThe testing of tensile bond strength, one of the main parameters to evaluate the performance of mortar renderings, is prescribed by different national and international standards. However, the existence of conflicting or under-specified parameters causes high variability of results for the same test situation. Hence, the aim of this study is to evaluate the influence of certain test parameters in the variability of the results for bond strength. The study was done in two stages: using a computer model using the Finite Element Method (Ansys® program), and an experimental study (in a laboratory), by doing tensile bond strength tests on mortar renderings applied on concrete slabs, with a total of 530 specimens. The results show that the geometry and dimension of the test specimen, the cutting procedure, the equipment type, loading rates and eccentricity contribute to the variability of the results. Additionally, there was a direct relationship between bond strength and the moisture of the rendering at the time the test was undertaken.