Title: Development Length of Headed Bar Based on Nonuniform Bond Stress Distribution

Author(s): Hyeon-Jong Hwang, Hong-Gun Park, and Wei-Jian Yi

Publication: Structural Journal

Volume: 116

Issue: 2

Appears on pages(s): 29-40

Keywords: bearing force; bond strength; bond test; development length; headed bar.

DOI: 10.14359/51712274

Date: 3/1/2019

Abstract:
The anchorage capacity of headed bars shows large variations according to design conditions, such as diameter of reinforcing bars, location of anchorage, and the use of fiber-reinforced concrete. In the present study, a design method was studied considering such various design conditions. In the proposed model, the anchorage strength of a headed bar was defined as the sum of the contributions of the straight bar length and the head bearing. Particularly, a nonuniform bond stress distribution model was used for the straight bar length. The proposed method was applied to 361 existing test specimens with various conditions of headed bar anchorage, including compression-compression tension (CCT) node, lap splice, and beam-column joint. The predicted results were compared to the existing test results and the predictions of current design codes including ACI 318 and Model Code 2010. The results showed that the proposed model predicted the test results with reasonable precision.