Although strut-and-tie models (STM) appear to provide safe, lower-bound designs for irregular concrete members, there have not been many experimental validations of them. This paper presents the result from two series of testing of STM specimens. In the first series, 6 specimens having different reinforcing designs but the same overall geometry and loading pattern were tested. In the second phase, 2 larger specimens were tested to investigate the size effect on STM tests. The design of each test specimen was developed using the ACI 318-05 provisions for STM. An unreinforced specimen was also constructed for comparison. Each reinforced specimen resisted loads greater than the factored design load and exhibited little distress at service load levels. Results confirm that the STM is a conservative yet flexible design approach.