Tensile behavior of new 2,200 MPa and 2,400 MPa strands according to various types of mono anchorage

Abstract

High-strength strands are widely used as a key structural element in cable-stayed bridges and prestressed concrete structures. Conventional strands for stay cable and tendons in prestressed concrete structures are <TEX>${\phi}$</TEX>15.7mm coated seven-wire strands and <TEX>${\phi}15.2mm$</TEX> uncoated seven-wire strands, respectively, but the ultimate strengths of both strands are 1860MPa. The objective of this paper is to investigate the tensile behavior of a newly developed <TEX>${\phi}15.7mm$</TEX> 2,200 MPa coated strand and a <TEX>${\phi}15.2mm$</TEX> 2,400 MPa uncoated strand according to various types of mono anchorages and to propose appropriate anchorages for both strands. Finite element analyses were initially performed to find how the geometry of the anchor head affects the interaction among the anchor head, the wedge and the strand and to find how it affects the stress distributions in both parts. Tensile tests for the new strands were carried out with seven different types of mono anchorages. The test results were compared to each other and to the results obtained from the tensile tests with a grip condition. From the analysis and the test results, desirable mono anchorages for the new strands are suggested.