Shear strength and deformation patterns of R/C walls with aspect ratio 1.0 and 1.5 designed to Eurocode 8 (EC8)

The deformation modes are investigated which develop in the critical regions of reinforced concrete (R/C) walls subjected to inelastic cyclic loading. A general method for wall design against shear failure, in particular sliding shear failure that occurs at high ductility levels, is suggested. This method of estimating sliding shear strength takes into account the presence or not of bidiagonal reinforcement at the critical area of R/C walls. Proposed models are compared with experimental results, as well as code provisions. Some open questions regarding wall design and detailing are addressed. An analytical approach for predicting the magnitude of displacement components of R/C wall specimens is also presented. Examples of application of this methodology in wall specimens tested to failure are then presented. Measurements of purposely located elongation meters (LVDTs) are used for the application of the proposed methodology. Conclusions are drawn regarding the breakdown of total horizontal displacement into flexural, shear and sliding shear components at each displacement-ductility level. Diagrams resulting from the application of this methodology are also presented, indicating that the sliding shear deformation mechanism becomes critical for shear walls with an aspect ratio between 1.0 and 1.5.