Strength Evaluation of Existing Concrete Buildings

Description

This report provides recommendations to establish the loads that can be sustained safely by the structural elements of an existing concrete building. The procedures can be applied generally to other concrete structures, provided that appropriate evaluation criteria are agreed upon before the start of the investigation. This report covers structural concrete, including conventionally reinforced cast-in-place concrete, precast-prestressed concrete, and post-tensioned cast-in-place (concrete).

The procedures recommended in this report apply wherestrength evaluation of an existing concrete building isrequired in the following circumstances:

•Structures that show damage from excess or improper loading, explosions, vibrations, fire, or other causes;

•Structures where there is evidence of deterioration or structural weakness, such as excessive cracking or spalling of the concrete, reinforcing bar corrosion, excessive member deflection or rotation, or other signs of distress;

•Structures suspected to be substandard in design, detail, material, or construction;•Structures where there is doubt as to the structural adequacy and the original design criteria are not known;

•Structures undergoing expansion or a change in use or occupancy and where the new design criteria exceed the original design criteria;

•Structures that require performance testing following remediation (repair or strengthening); and

•Structures that require testing by order of the building official before issuing a Certificate of Occupancy