Influência do tipo de tratamento e do uso de conectores na resistência de juntas em elementos de concreto

Abstract

The use of concrete joint is a common device in the construction industry, they may be necessary for constructive reasons, in cases of enlargement of a building, change of use of the structure or even the need to increase the bearing capacity of the structure. It is observed that the NBR 6118 does not provide recommendations for implementing or determination of resistance in connection concrete joints. We notice also that some international standards such as FIB (2010) and Eurocode 2 show divergences. In order to evaluate the influence of the treatment done in the joints and even the use of connectors on the ultimate strength of the bond, the concrete used in this study showed a compressive strength, the first and second concrete, approximately 18:46 MPa , respectively. In all specimens apicoamento were performed with the purpose of increasing the roughness of the bonding surface. The variables were compared with the use of structural adhesive and on the number of mechanical connectors with different arrangements and depths in the connecting joint. To analyze the deformation of the connectors strain gages were used. There was a tendency for increased shear strength in the part with the largest number of pins as well as the use of epoxy resins in connection influence the breaking strength, with more resistance than the column of reference. Among the expressions proposed in the policy recommendations for the evaluation of crack resistance in concrete interface, the analytical expression that is closer to the experimental results was the EUROCODE2 when analyzing the breakdown voltage by FIB (2010), this proved to be conservative.