This paper presents the results of an experimental study on the
anchorage strength of conventional and high-strength steel hooked
bars. Three hundred and thirty-seven exterior beam-column joint
specimens were tested with compressive strengths ranging from 4300
to 16,500 psi (30 to 114 MPa). Parameters investigated included
the number of hooked bars per specimen, bar diameter, side cover,
amount of confining reinforcement, hooked bar spacing, hook bend
angle, hook placement, and embedment length. Bar stresses at
failure ranged from 22,800 to 144,100 psi (157 and 994 MPa). The
majority of the hooked bars failed by a combination of front and
side failure, with front failure being the dominant failure mode. Test
results show that development lengths of hooked bars calculated
based on ACI 318-14 are very conservative for No. 5 (No. 16) bars
and become progressively less conservative with increasing bar
size and concrete compressive strength.