Title:
Seismic Behavior of Precast Columns with High-Strength Steel Coiled Strip Reinforcement
Author(s):
Ashley Thrall - University of Notre Dame
Publication:
CRC
Volume:
Issue:
Appears on pages(s):
34
Keywords:
DOI:
Date:
1/1/2023
Abstract:
This report presents the experimentally investigation of the behavior of square reinforced concrete (RC) columns with high-strength [100 ksi (690 MPa) yield strength] steel coiled strips as embedded confinement reinforcement under reversed-cyclic lateral loading and a constant axial compression load. Six full-scale specimens [20 in. x 20 in. (508 mm x 508 mm) cross-section] were tested with varying: (1) confinement type (strip versus reinforcing bar), (2) confinement layout (hoops/ties, single spiral, two spirals, two spirals out-of-phase), and (3) confinement reinforcement ratio. Findings include: (1) the strip-confined specimens had a similar peak strength as the rebarconfined specimen and the peak strength exceeded analytical predictions, (2) the initial stiffness of the stripconfined specimens was greater than the rebar-confined specimen, (3) all of the specimens met the ACI T1.1-01 criterion that the lateral load at 3.5% drift was not below 75% of the peak, and (4) strip-confined specimens demonstrated improved residual strength behavior compared to the rebar-confined specimen. Overall, this study demonstrates the promise of strip-confinement for RC columns in seismic regions.