Guide for Seismic Rehabilitation of Existing Concrete Frame Buildings and Commentary

Description

Earthquake reconnaissance has clearly demonstrated that existing concrete frame buildings designed before the intro-duction of modern seismic codes are more vulnerable to severe damage or collapse when subjected to strong ground motion. Seismic rehabilitation of existing buildings wherenew components are added or existing components are modified or retrofitted with new materials, or both, can beused to mitigate the risk to damage in future earthquakes. Seismic rehabilitation is encouraged not only to reduce the risk of damage and injury in future earthquakes, but also toextend the life of existing buildings and reduce using newmaterials in the promotion of sustainability objectives.

This guide describes methods for estimating the seismic performance of concrete components in an existing building.The guide is intended to be used with the analysis procedures and Rehabilitation Objectives (ROs) established inASCE/SEI 41-06 for the Systematic Rehabilitation Method.The methods described apply to existing concrete componentsof a building system, rehabilitated concrete components of abuilding system, and new concrete components added to anexisting building system. Provisions of this guide do notapply to concrete-encased steel composite components.