Correlating Q-Factor Measurements to Other Parameters in Deteriorated Concrete

Abstract

The impact-echo technique is a nondestructive test used to detect flaws in concrete. Although deterioration can be quantified through the Q-factor, little is known about its relationship to other parameters. This research study explored possible correlations between Q-factors and other parameters including expansion change, weight change, and compression strength in deteriorated concrete. The effect of adding potassium carbonate to accelerate deterioration in concrete was also investigated. Two batches of concrete were used: a control batch with no additional potassium carbonate added and a batch made with a total of 2.06% of potassium carbonate by weight of cement. The specimens were deteriorated through the UMD Modified Duggan Cycle or one of two sets of Freeze-Thaw cycles. The specimens subjected to the heating cycle did not show strong correlations between Q-factors and the other parameters. However, those used in the first set of Freeze-Thaw cycles experienced heavy deterioration and showed strong correlations between Q-factors and expansion and weight change and those from the second set revealed even stronger correlations.