Beam C4

Approximate beam span, L =51 inches. Beam width, b =7.75 inches. Height of beam, h = 9 inches. Two #3 rebar at bottom of beam for bending reinforcement. No shear reinforcement. Estimated materials for steel fy=60 ksi, for concrete fc'=4 ksi. Mid span point load causing bending. Yield load 7.76 kips, Ultimate load 12.3 kips. Actuator preprogrammed to load the beam with 3 inches of displacement. Failure begins to be ductile with bending yielding, but bending reinforcement didn't go to end of beam like it should so suddenly a brittle shear failure destroyed the beam. Evidence showed that bar ends pulled out at the bottom near the support leading to rapid failure.