scope:

The scope, purpose, applicability, exclusions, interpretation principles, language, and units of measure are defined in this chapter.

The "general existing building code" refers to the code adopted by a jurisdiction that regulates existing buildings.

The general existing building code establishes the limit to which a repair and rehabilitation can occur in accordance with the original building code. Above these limits, the repair and rehabilitation is in accordance with the general building code. The general existing building code in the United States is usually based on the International Existing Building Code (IEBC) developed by the International Code Council. The IEBC is revised every three years and was first published in 2003.

The "general building code" refers to the building code adopted by a jurisdiction that regulates new building design and construction. The "original building code" refers to the general building code adopted by a jurisdiction at the time the existing building was constructed.

The general building code establishes the design requirements for construction materials. The general building code in the United States is usually based on the International Building Code (IBC) published by the International Code Council. The IBC is revised every three years and was first published in 2000. For the design and construction of concrete structures, the IBC and legacy codes reference ACI 318, Building Code Requirements for Structural Concrete, with exceptions and additions.

The "design basis code" is the general building code or the original building code under which the evaluation, repair, and rehabilitation are implemented. If a jurisdiction has adopted a general existing building code, the design basis code shall be determined in accordance with Chapter 4. If a jurisdiction has not adopted a general existing building code, 1.3 applies.

The general existing building code establishes limits to which a repair and rehabilitation can occur in accordance with the original building code. Above these limits, the repair and rehabilitation is in accordance with the general building code.

This code is intended to supplement the evaluation requirements of the general existing building code.

This code provides evaluation procedures for existing concrete structures. It also provides material and design requirements that allow the licensed design professional to bring existing concrete structures in compliance with building codes written for new construction.

This code provides minimum material and design requirements for the repair of damaged, deteriorated, or deficient structural concrete members and systems repaired in accordance with the design basis code. Structural repair includes restoring or increasing strength and deformation capacities as well as the durability of existing members.

This code supplements the general existing building code and shall govern in all matters pertaining to the evaluation, repair, rehabilitation, strengthening of concrete members, and concrete sections of composite members in existing concrete buildings, except wherever this code is in conflict with the requirements in the general existing building code. Wherever this code is in conflict with requirements in other referenced standards, this code shall govern.

Provisions for seismic resistance

Seismic evaluation and rehabilitation design shall be in accordance with the general existing building code.

Where seismic rehabilitation is not required by the general existing building code, voluntary seismic rehabilitation shall be permitted.

Conditions for such evaluation and repair are provided in ACI 369R, ASCE/SEI 31 and ASCE/SEI 41. Significant improvements to a building's seismic performance can be made using repair techniques that provide less than those detailing and reinforcement methods required for new construction. As an example, providing additional reinforcement to confine concrete in flexural hinging regions will increase the energy dissipation and seismic performance even though the amount of confinement reinforcement may not satisfy the confinement requirements for new structures (Kahn 1980, Priestley et al. 1996; Harris and Stevens 1991).

Components of the seismic-force-resisting system that require strength and ductility should be identified. Force-controlled (nonductile) action is acceptable for some classifications of components of the seismicforce- resisting system (ASCE 41). The strength requirement of 7.1 is applicable to these force-controlled components. ASCE 41and ACI 369R provide information on seismic rehabilitation. Seismic-resisting components requiring energy-dissipating capability should maintain the ability to dissipate energy when repaired. Design and detailing requirements for proper seismic performance of cast-in-place or precast concrete structures are addressed in ACI 318 and 369R.

This code does not provide complete design procedures or construction means and methods.

This code is not intended for repair of nonstructural concrete or for aesthetic improvements except if the failure of such repairs would result in an unsafe condition.

Licensed design professional

All references in this code to the licensed design professional shall be understood to mean persons who are licensed to practice structural design in the jurisdiction where this code is being used. The licensed design professional for a project is responsible for and in charge of the evaluation or repair design or both.

The licensed design professional must exercise sound engineering knowledge, experience, and judgment when interpreting and applying this code.

The licensed design professional is permitted to require evaluation, design, construction, and quality assurance that exceed the minimum requirements of this code.