Partially Funded by the National Science Foundation’s Research Initiation Grant. Investigators – Y. H. Chai and D. T. Elayer.
Abstract: Depending the level of ductility imposed on a reinforced concrete wall, tensile strains as high as 3% may be developed in the end-regions of the wall. The large tensile strain is a cause for concern since the lateral stability of the wall depends on the magnitude of the tensile strain. Wide cracks developed by a large yield excursion must be closed before the in-plane lateral strength of the wall can be fully developed in the reversed direction. A critical condition exists prior to closing of the cracks where an excessive out-of-plane displacement may occur causing the wall to become unstable. In this project, reinforced concrete columns with details representative of the end region of the wall were tested under reversed cyclic axial tension and compression. Based on the test results, a kinematic model was developed for estimating the maximum tensile strain that may be imposed on a ductile reinforced concrete wall. The model was shown to provide a conservative estimate of the maximum tensile strain that may be imposed on the wall, and the model may be further developed into a criterion for specifying the minimum wall thickness of ductile planar walls.
For photos of test setup and observed failures, click here.
Key Publication:
- Y. H. Chai and T. D. Elayer (1999), “Lateral Stability of Reinforced Concrete Columns under Axial Reversed Cyclic Tension and Compression”, ACI Structural Journal, Vol. 96, No. 5, pp. 780-789.
- Y. H. Chai and S. K. Kunnath (2005), “Minimum Thickness for Ductile RC Structural Walls”, Engineering Structures, Vol. 27, pp. 1052-1063.