Title:
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:
122
Issue:
3
Appears on pages(s):
147-159
Keywords:
bond splitting; columns; high-strength reinforcement; large bar; longitudinal reinforcement; seismic
DOI:
10.14359/51745668
Date:
5/1/2025
Abstract:
This research proposes a standardized arrangement of longitudinal
reinforcement using Grade 690 MPa (100 ksi) high-strength steel
and D32 (No. 10) or D36 (No. 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 to 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.