College of Architecture and Environmental Design
Architectural Engineering Department
BS in Architectural Engineering
The Sylmar earthquake of 1971 caused significant damage to slender, non-ductile reinforced concrete (RC) shear wall buildings in California. A later survey by the Concrete Coalition in 2011, under the guidance of EERI members, indicated that there are over 3000 vulnerable concrete buildings in California . This led to City of Los Angeles (LA) Ordinance 193893 enacted in 2015, which requires mandatory upgrades to these concrete buildings by 2035. Current practice to meet the requirements of this ordinance, with respect to RC wall buildings, involves adding new shear walls to the building plan or increasing the cross-sectional area of existing walls using shotcrete. Both options are invasive, costly, and time consuming as they increase the strength of the walls, requiring additional upgrade of the slabs and foundation.
The experimental test program described in this report, occurring at the California Polytechnic State University (Cal Poly), College of Architecture and Environmental Design (CAED) High Bay Laboratory, will consist of a non-ductile reinforced concrete (RC) wall modelled after pre 1980’s walls. The shear wall will be retrofitted with fiber reinforced polymer (FRP) sheets wrapped around the wall boundary elements over the height of the plastic hinge region. The goal of this retrofit application is to provide improved confinement of the concrete to increase the ductility of the wall, with minimal increase in strength. The collaborative team of industry members, faculty advisors, and student researchers hopes to see improvements in the compressive strain capacity in the boundary element concrete and increase the global displacement capacity. FRP splay anchors are also used to prevent delamination of the FRP sheets bonded to the concrete. This report provides a literature review of past FRP use on RC shear walls, specimen design, experimental test setup, and the construction approach. If effective, this retrofit strategy will provide a cost and time efficient means of improving the seismic performance of slender, non-ductile concrete structures with walls as the primary lateral force resisting system.