| |
Non-Destructive Testing of a concrete building located in a corrosive environment
During a recent evaluation of the Marine Resources Center, Laboratory and Teaching Facility at the Department of Natural Resources (DNR) in Charleston, South Carolina, the staff noted conditions of concern in the concrete structure under the wet labs. These findings prompted an investigation of the structure’s condition and stability. The Marine Resources Center was constructed in the mid 1970's, and has been exposed to saltwater throughout the entire lifespan of the building. Saltwater is used inside the building in the wet labs causing chlorides to be introduced from the top side of the lab. In addition, the building is situated adjacent to the Charleston harbor exposing the bottom side of the slab and the support structures to saltwater during extreme storm events.
GEL Geophysics, LLC conducted a visual inspection and non-destructive testing (NDT) of concrete floor slabs, and supporting beams and columns at the client's facility. The NDT part of the investigation involved the use of Ground Penetrating Radar, Cover Meter, Half-Cell Potential, and Rapid Chloride Test. The objective of the investigation was to determine the present condition of the structure, and potential for future additional damage. Several degraded structural conditions were found, including deteriorated reinforcement, spalled concrete, cracked concrete, and rust stained concrete, all of which demonstrate some degree of structural failure. Through the use of NDT, additional areas within the slabs and beams were identified where reinforcement corrosion had commenced, but not progressed enough to cause visual indications. There was evidence of overall salt intrusion into the concrete both from the top side and the bottom side of the slab and beams.
As a result of our investigation, our client discovered that the concentration of chloride in the concrete was high enough that it could cause corrosive action on the embedded reinforcement if the concrete gets wet. In order to mitigate further damage, the concrete must be kept dry.
back
| |
|
|
