Title:
Prepublished: Cyclic Behavior of Columns with Proposed Arrangement of Longitudinal Reinforcement
Author(s):
Yu-Chen Ou, Cong-Thanh Bui, Yu-Ting Lin, and Sheng-I Yen
Publication:
Structural Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
bond-splitting; columns; high-strength reinforcement; large bar; longitudinal reinforcement; seismic
DOI:
10.14359/51745668
Date:
3/10/2025
Abstract:
This research proposes a standardized arrangement of longitudinal reinforcement using Grade 690 MPa (100 ksi) high-strength steel and D32 (#10) or D36 (#11) large-diameter threaded bars to alleviate reinforcement congestion and construction difficulties. Four full-scale column specimens with the proposed standardized arrangement were tested using double-curvature lateral cyclic loading to examine their seismic performance. Test results showed that all the columns exhibited a combined axial and flexural failure mode, with ultimate drift ratios ranging from 4.07 to 5.98%, ratios of measured to nominal moment strength based on actual material strengths ranging from 1.18-1.51, and relative energy dissipation ratios satisfying the requirement of ACI 374.1-05. No shear or bond-splitting failures were observed. Based on the test data from this research and the literature, two modifications were proposed in the calculation of ld to relax the requirement of 1.25ld≤lu/2 as required by ACI 318-19.