a. Evaluation. The first step is to evaluate the
current condition of the concrete. This evaluation may
include a review of design and construction documents, a
review of structural instrumentation data, a visual examination,
nondestructive testing (NDT), and laboratory
analysis of concrete samples. Upon completion of this
evaluation step, personnel making the evaluation should
have a thorough understanding of the condition of the
concrete and may have insights into the causes of any
deterioration noted.
b. Relating observations to causes. Once the evaluation
of a structure has been completed, the visual observations
and other supporting data must be related to the
mechanism or mechanisms that caused the damage. Since
many deficiencies are caused by more than one mechanism,
a basic understanding of causes of deterioration of
concrete is needed to determine the actual damage-causing
mechanism for a particular structure.
c. Selecting methods and materials. Once the
underlying cause of the damage observed in a structure
has been determined, selection of appropriate repair materials
and methods should be based on the following
considerations:
(1) Prerepair adjustments or modifications required
to remedy the cause, such as changing the water drainage
pattern, correcting differential foundation subsidence,
eliminating causes of cavitation damage, etc.
(2) Constraints such as access to the structure, the
operating schedule of the structure, and the weather.
(3) Advantages and disadvantages of making permanent
versus temporary repairs.
(4) Available repair materials and methods and the
technical feasibility of using them.
(5) Quality of those technically feasible methods and
materials to determine the most economically viable to
ensure a satisfactory job.