Title: Lateral Behavior of Columns With High-Strength Steel Coiled Strip Confinement
Date Published: January - February 2025
Volume: 70
Issue: 1
Page Numbers: 38 - 57
Authors: Steven M. Barbachyn, Shane Oh, Lily A. Pearson, Ashley P. Thrall, Brad D. Weldon, and Yahya C. Kurama
https://doi.org/10.15554/pcij70.1-01
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Abstract
This paper presents the experimental investigation of the behavior of square reinforced concrete columns with high-strength (100 ksi [690 MPa]) steel coiled strips as embedded confinement reinforcement under reversed-cyclic lateral loading and constant axial compression load. Six full-scale specimens (20 × 20 in. [508 × 508 mm] cross section) with the following variations were tested: confinement type (strip or reinforcing bar), layout (hoops and ties, spirals), and reinforcement ratios. The strip-confined specimens had similar peak strengths as a specimen confined by reinforcing bar ties, and this strength exceeded analytical predictions. The stiffness of the strip-confined specimens was greater than the reinforcing-bar-confined specimen. In accordance with the American Concrete Institute’s Acceptance Criteria for Moment Frames Based on Structural Testing (T1.1-01), all specimens met the criterion that the lateral load at 3.5% drift was not below 75% of the peak. Strip-confined specimens demonstrated improved residual strength behavior relative to the reinforcing-bar-confined specimen. Overall, the study demonstrated the promise of steel strip confinement for reinforced concrete columns in seismic regions.