A recent successful load test on a steel-fiber-reinforced-concrete beam, free of congestion-causing diagonal reinforcing steel, promises to positively impact constructibility of tall, moment-resisting frames in seismic zones. Using SFRC, engineers can reinforce high-aspect-ratio link beams, which span openings in shear walls, as regular beams, say the test’s researchers.
“We have a design for which you do not need diagonal bars, and you can still achieve large drift capacity under very high shear forces,” says Gustavo J. Parra-Montesinos, the test’s lead researcher and a Dept. of Civil and Environmental Engineering professor at the University of Michigan, Ann Arbor. In the future, engineers will be able to use steel fibers to replace transverse reinforcement for confining concrete or shear strength in seismic applications, he says.