Lau, David

Repair of Earthquake Damaged Squat Reinforced Concrete Shear Walls Using Externally Bonded Cfrp Sheets

Abstract eng:
This study investigates the effectiveness of using externally bonded carbon fiber-reinforced polymer (CFRP) sheets to prevent premature shear failure and improve the seismic performance of deficient squat reinforced concrete (RC) shear walls. The wall specimens are designed using older less-stringent design standards [CSA A23.3-77; ACI 318-68] to replicate low-rise shear walls representative of construction practices during the 1960s and 1970s. The deficient design details in the specimens include insufficient shear reinforcement, a lack of concrete confinement at the ends of the shear wall and lap splices of the longitudinal reinforcement in the potential plastic hinge region. The shear wall specimens described in this study are tested first under reversed cyclic load to simulate the damage and drift effects of an earthquake on the wall. Externally bonded CFRP sheets are applied to the surfaces of the specimens as a minimally disruptive rehabilitation strategy for walls that have been damaged during an earthquake and need to be repaired. The performance of the retrofitting strategy is evaluated in terms of its potential to improve the lateral-load carrying capacity, ductility and energy dissipation capacity of the specimens. Experimental results show that squat RC shear walls with detailing deficiencies are susceptible to brittle modes of failure, including diagonal tension shear failure and lap splice splitting failure. In a deficient wall specimen without lap splices, the CFRP rehabilitation is shown to be successful in avoiding brittle shear related failures and allowing the flexural steel reinforcement to yield resulting in improvements in lateral load carrying capacity. In a specimen with sufficient lap splice length, the CFRP rehabilitation strategy is shown to be effective in completely restoring the in-plane strength of the specimen while also slightly improving the ductility and energy dissipation capacity.

Contributors:

Woods, Joshua

Conference Title:

Proceedings of the 16th World Conference on Earthquake Engineering

Conference Title:

16th World Conference on Earthquake Engineering

Conference Venue:

Santiago (CL)

Conference Dates:

2017-01-09 / 2017-01-13

Rights:

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