Berkeley-2 (NCBF-B-2): Concrete-Filled Brace Repair of Non-Seismically Detailed Concentric Braced Frame (NCBF)

The NCBF-B-2 test specimen utilized the existing frame from the NCBF-B-1 test conducted on October 11, 2013. The columns, beams, and 1st story braces and gusset plates were re-used from the original test specimen. The damaged 2nd story braces and gusset plates from the NCBF-B-1 test were replaced with the same sections and sizes as the original specimen. All four braces were filled with low strength concrete with a nominal compressive strength of 2000psi. The width-to-thickness ratios of the concrete-filled HSS braces did satisfy the highly ductile brace criterion of the AISC 341-10 Seismic Provisions (b/t limit of 1.4√(E/Fy)=35.2). Reinforcing plates were added to all four braces at the net section region. The frame was tested under quasistatic loading conditions with a triangular load distribution over the height of the frame. Testing was split into two parts: Part A and Part B due to slight modifications in the test setup to allow for further testing of the frame to greater failure modes.