Applying Covercrete Absorption Test to In-Situ Tests on Structures

Abstract

Many permeation methods for characterizing the near-surface quality of concrete claim to have the added advantage of being applicable in situ. This paper attempts to highlight some of the aspects associated with using such tests in situ, and deals specifically with experience in using the covercrete absorption test (CAT) for in-situ tests on concrete structures. Some of the better known permeation test methods are listed, and reasons are given for selecting the CAT for this investigation, in preference to other methods. Results of CAT tests performed in the laboratory on laboratory cast samples showed the CAT can be sensitive to variations in water/cement ratio and curing time, moisture content at the time of test, and surface orientation. Good correlations between covercrete absorption and other durability index parameters were obtained for the laboratory-cast samples, but these correlations were poor or even absent when applied to in-situ tests on mature concrete structures. From these tests it appears that permeation methods have little value for assessing the quality and state of durability of concrete structures.