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Saud, Deepak

University of British Columbia

The jointed post-tensioned Precast Concrete (PC) shear walls are designed to rock around their base and self-center themselves upon unloading. One way to enhance ductility is by allowing controlled rocking at the wall-to-foundation connection using unbonded Post-tensioning (PT) tendons and mild steel rebars as energy dissipators in PC shear wall buildings. However, this jointed connection system is complex to build and time-consuming. Also, the jointed connection with grouted metal duct connections with deformed steel rebar as dowel rebar has limited ductility. A particular unknown exists about the force deformation capacity of grouted dowel connection. This thesis aims to investigate the local behavior of the PC wall through a novel connection using shape memory alloy (SMA) rebar and couplers. The study started with a numerical study to investigate the effects of various parameters (aspect ratio, axial load ratio, rebar types, and vertical reinforcement ratio) on the seismic response of the concrete shear walls reinforced with SMA bars at the base. Fifty-four finite element models of the RC walls reinforced with SMA rebars and steel were developed. The results were analyzed to evaluate the seismic behavior of SMA RC walls, which improved the understanding of SMA PC walls. Additionally, four coupler pullout tests and seven pullout tests of rebar in concrete blocks were carried out to investigate the effectiveness of the anchorage of the SMA rebar connected with the coupler and surrounding grout within a metal duct. The test results ensured the rebar was stressed beyond the superelastic strain range with very low slippage. Finally, three small-scale wall-to-wall connection test specimens were constructed and tested under monotonic loading to investigate the force-deformation response of the proposed anchoring system for SMA-reinforced PC wall-to-wall intersections. The result shows that specimens with the proposed connection consisting of SMA and couplers present higher yield displacement, yield and ultimate load capacity, and hardening ratio compared to the specimens with steel and couplers.

Text

2024-10-07

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/89343

Civil Engineering

University of British Columbia

UBCO

http://creativecommons.org/licenses/by-nc-nd/4.0/