Reinforced Concrete Structural Walls without Special Boundary Elements

Two large-scale reinforced concrete walls without ACI 318-14 special boundary elements were tested under constant axial gravity load of 0.053Agfc' combined with reversed-cyclic, quasi-static lateral loading, and overturning moment applied at the top of the wall. Damage initiated with spalling of cover concrete and buckling of longitudinal reinforcement, followed by eventual fracture of longitudinal reinforcement and crushing of the concrete core. Failure occurred during the third loading cycle at 1.5% plastic hinge rotation for one wall, and during the first loading cycle at 2.0% plastic hinge rotation for the other. Using results from these tests and other tests on walls without special boundary elements, recommendations are made for deformation capacity/limits, effective stiffness, and additional backbone and hysteretic modeling parameters. An existing model for buckling of vertical reinforcement was extended, and a new limit for the ratio of longitudinal reinforcement unsupported length to bar diameter (s/db is recommended.