Abstract
Recent earthquakes in Chile and New Zealand provide significant opportunity for real-world evaluation of seismic performance of modern reinforced concrete structural walls. Observations following these earthquakes indicate that the behavioral aspects of structural walls are still not fully understood and require further study. Moreover important design assumptions may be impacted by the observed behavior, making research and in particular experimental research, an urgent need. Few large scale experimental assessments of modern structural wall behavior exist due to both the cost of testing, the facility requirements for the testing, and the rapid evolution of reinforced concrete seismic design rules. Helping to fill the voids in the existing experimental data, an extensive ongoing research project aims to investigate the deformation behavior of reinforced concrete structural walls under load reversals indicative of seismic ground motions. This paper presents the experimental plan for the project, as well as preliminary results and discussion based on early tests. The primary goal of the project is to investigate a range of modern structural wall design aspects, and isolate those characteristics most critical to seismic performance for further review. The investigation focuses on an array of design parameters, such as: reinforcement configuration, reinforcement ratio, axial load ratio, loading protocol, wall slenderness, and wall geometry. Large-scale testing (one-half scale) of wall specimens is configured to represent the lower first and second floors of a 10 to 15 story building designed with a full height, cantilever-type structural wall lateral force resisting system. Shear, moment, and axial loads are applied during each test to accurately portray the anticipated demands on the lower floors of a structure. Specimen designs meet current United States code requirements for high ductility structural walls, specifically those provided by the American Concrete Institute (ACI 318-11, Chapter 21) for the seismic design of reinforced concrete structures.