Correlating Durability Indicators to Resistivity and Formation Factor of Concrete Materials

Abstract

Concrete pavement durability in the United States is an important characteristic that owners are considering in new construction and rehabilitation projects, and many are including durability tests in the next generation of their specifications. Specifically, focus has fallen on electrically based testing owing to its rapid testing time and economical testing equipment. Results from electrically based tests have also been shown to be good inputs to service life models and can correlate with a wide range of other material properties used to understand how ions and fluid are transported through concrete. This study aimed to correlate the two most common electrically based test results (resistivity and formation factor) with more established and involved tests of transport properties, such as rapid chloride migration and water absorption. The major difference between these two tests resides in the conditioning solution, which is typically limewater for resistivity and an alkali-concentrated solution for the formation factor. Based on the results, both electrical resistivity and formation factor were deemed acceptable tools for mixture approval and acceptance, though formation factor demonstrated higher correlations with the other transport properties and, therefore, was preferrable for performance modeling. Overall, concrete resistivity and formation factor measurements at ages beyond 28 days could be used to indicate the durability of a concrete material during its lifespan. During the investigation, the authors observed that compressive strength measurements were independent of the type and volume of the conditioning solution.