Processes

ERTesting provides testing and field services for condition assessment, corrosion monitoring, and estimating remaining service life for in-service reinforcements. Test protocols utilize electrochemical tests and wave propagation techniques, geophysical testing, and more invasive techniques such as load testing, and direct observation of exhumed reinforcements. We have state-of-the-art equipment for performing nondestructive in situ testing including measurements of half-cell potential, various DC and AC (steady-state and transient) electrochemical measurement techniques, and mechanical tests including sonic echo (SE), impulse response (IR) and ultrasonic testing (UT).

Half-cell potential and other electrochemical tests provide information about the nature of the exposed metal surface, the presence of corrosion products, the integrity of the corrosion protection system, and corrosion rate.  Although these tests are indicative of durability they do not provide information relative to the locations and features of problem areas. More specific information may be obtained from mechanical tests including SE, IR and UT that are used to assess as-built details, and to locate areas with loss of cross section (i.e., severity of corrosion) or gout cover. Grout columns that surround the metal reinforcements for  corrosion protection are also  probed via SE and IR tests to reveal the locations of voids or sections of grout that may be compromised by cracking. Results from SE and IR tests can also be used to  identify elements with loss of prestress, which may be due to other factors affecting service life, including creep.

Direct physical observations are necessary to verify results from nondestructive testing (NDT). Although direct physical observations provide limited information with respect to spatial and temporal variations, supplementing these observations with results from NDT helps to overcome these limitations. When these two approaches are implemented together, results from NDT are used to select times and locations for destructive test samples.