Title: Coupling Beams with Welded Grids under Reversed Cyclic Loading

Author(s): Okan Ozcan and Murat Saatcioglu

Publication: Structural Journal

Volume: 115

Issue: 4

Appears on pages(s): 1199-1212

Keywords: coupling beams; earthquake-resistant design; shear; welded grids

DOI: 10.14359/51702237

Date: 7/1/2018

Abstract:
Seismic behavior of concrete coupling beams reinforced with welded reinforcement grids was investigated experimentally. Eight near-full-scale reinforced concrete coupling beams were tested under simulated seismic loading. Test parameters included grid spacing, grid configuration, and concrete compressive strength. The effects of two-legged and four-legged grids, spaced at one-half and one-quarter of the effective section depth, resulting in two different shear-to-moment capacity ratios, were investigated while using normal-strength and high-strength concretes. The primary objective of the test program was to assess the performance of grids, and especially the grid welds, under earthquake-induced shear force reversals. Test results indicated that the grids provided higher shear capacities than those computed based on ACI 318-14, but they experienced weld failures at later stages of loading, limiting inelastic beam deformability. Grids that pass “grid burst tests,” ensuring sufficiently high weld capacity beyond the rupturing of grid reinforcement, are expected to possess both the required strength and inelastic deformability for use in earthquake-resistant construction.