Influence of cyclic loading and frost on the behavior of bond of three-wire strand

摘要

This paper presents the results of an experimental research investigating the influence of static and cyclic loading and frost impact on the bond between concrete and 6.2 mm three-wire-strand. From the pullout tests, it was determined that a cyclic load did not negatively influence the bond strength of three-wire strand. On the contrary, the influence of cyclic loading after 200 freezing and thawing cycles resulted in a significant decrease of bond strength of three-wire strand. Additionally, the new parameters for bond stress-slip relationship suggested in Model Code 2010 are proposed for the 6.2 mm three-wire strand cast with concrete having compressive strength of 82.6 MPa with standard deviation of 6.65MPa. The results of dynamic coefficient b for 6.2 mm three-wire strand used in relationship between a slip of reinforcement and a number of loading cycles under unidirectional cyclic loading suggested in Model Code 2010 are analyzed.