Guide for Testing Reinforced Concrete Structural Elements under Slowly Applied Simulated Seismic Loads

Description

Seismic design practice worldwide is moving toward performance-based design of buildings. This approach aims at producing buildings capable of developing predict-able performance levels to achieve predefined performance objectives when subjected to earthquake ground motions. The performance objectives are met by ensuring the struc-ture and its components achieve target performance levels associated with different states of damage for specified seismic hazards. Usually, the seismic hazard is expressed in terms of the intensity of ground motion for a specified return period. Performance levels (capacity) that can be devel-oped by structural components and ground motion intensity (demand) for which the building is designed form the funda-mental framework of performance-based seismic design of buildings.

The design of structural components for target perfor-mance levels requires an assessment of strength, stiffness, and deformation characteristics typically into the nonlinear range of elements and subassemblies that make up the seismic-force-resisting system. Despite advances in compu-tational techniques and increased computing power, avail-able analytical approaches and computational models based on the principles of mechanics may not be sufficiently accu-rate for design.

This is especially true for performance-based design of concrete buildings for which the knowledge of seismic performance of structures during loading, unloading, and reloading beyond post-cracking and post-yielding stages of deformations, including strength and stiffness degrada-tion under reversed cyclic loading, becomes vitally impor-tant. For this reason, tests of large-scale specimens repre-senting actual conditions in the field are needed to generate fundamental knowledge on inelastic behavior of reinforced concrete structural components and subassemblies.