Prediction of Chloride Penetration in Concrete

Federal Highway Administration2001PDFTech ReportHooton, R. D.Stanish, T. K.United States. Federal Highway Administration. Office of Infrastructure Research and DevelopmentUniversity of TorontoLane, SusanSimon, MarciaUnited States. Federal Highway Administration. Office of Infrastructure Research and DevelopmentUnited StatesConcreteHigh performance concreteChloridesPermeabilityTestingQuality controlCorrosionConcretehigh-performance concretechloride penetrationtestingquality controlcorrosionRapid Migration Test (RMT)FHWA-RD-00-142DTFH61-97-R-00022Lane, Susan; Simon, MarciaContracting Officer's Technical Representatives (COTRs): Susan Lane (HRDI-06) and Marcia Simon (HRDI-12).The objective of this study was to identify or develop a test for predicting chloride penetration in concrete, to be used for evaluating new mixes, for accepting or rejecting new concrete according to specifications, and for evaluating in-place concrete. The test was intended to supplement or replace the use of AASHTO T27-93 "Electrical Indication of Concrete's Ability to Resist Chloride." In this study, different test procedures were evaluated for use in predicting the chloride penetration resistance of concrete in a short time frame (less than 35 days). The test results were correlated to those of long-term salt ponding and diffusion tests. In the first phase, a number of tests identified in the literature were subjected to a preliminary screening process. In the second phase, test identified as promising were subjected to a more rigorous evaluation. In the third phase, the best test procedure was further examined. As a result of this work, the Rapid Migration Test (RMT) was identified as the most successful. The RMT involves using an electrical potential to drive chloride ions into a concrete sample for a specific test duration and then evaluating the depth of chloride penetration with a colorimetric indicator. The RMT correlates as well or better than AASHTO T277 with the long term ponding tests and was able to evaluate correctly a wider variety of concretes, including those with corrosion inhibitors. The quantitative parameter obtained in the RMT was related to those from AASHTO T277 in the high performance concrete (HPC) grades identified by Goodspeed, Vanikar, and Cook (1996). As part of the work described above, an interlaboratory evaluation was performed to assess the RMT and to refine the procedure.96