This paper investigates
an assessment method for Corten steel (CS) ancillary structures on the Charleston
interstate highway system (I-64, I-77, and I-79). Nineteen CS bridge-mounted
ancillary support (CS-BMAS) structures (i.e., ancillary structures are attached
to bridge superstructure) were examined by non-destructive testing techniques. Ultrasonic testing (UT) was
used to inspect key components of the ancillary sign structures (e.g., anchor
bolts, connection brackets, etc.) while the other components were assessed by a
conventional visual inspection method. The CS-BMAS structures were rated at
both the overall and element levels (each ancillary structure includes more
than ten elements/components such as foundations/concrete in the vicinity of
connections, mounting plates, anchor bolts, vertical tubular members and their
connections, truss members and connections). The element level ratings were
based on the proposed rating criteria and score. The overall condition of each ancillary
structure was then obtained by the normalized S/S<sub>max</sub> ratio (where S
is the total score of each structure and S<sub>max</sub> is maximum possible
total score). The results revealed that most of the CS-BMAS structures
performed satisfactorily after more than four decades of service and exposure
to harsh environmental conditions. Specifically, two ancillary sign structures
(11%) were rated as good condition, 16 structures (84%) were rated as fair
condition, and one structure (5%) was found to be in poor condition.