NON-DESTRUCTIVE ASSESSMENT OF THE PERFORMANCE OF SURFACE-TREATED CONCRETE

This article reports on a laboratory investigation to evaluate the applicability of existing commercial test methods for nondestructive assessment of the conditions of surface-treated concrete, stone, or masonry; and following this initial assessment, to recommend a simple and reliable method or suite of methods that can be used to confidently diagnose the condition of treated surfaces. Tests performed included moisture content measurement, initial surface absorption test, Karsten Tube water absorption test, oxygen permeability, electrical resistivity, and total porosity. A simple but practical suite of tests was developed to enable an initial health check of treated surface to be made: moisture content, water absorption, and electrical resistivity. Water absorption and electrical resistivity were the most directly informative of the assessment tests. Assessment of a surface using these methods may be based on numerical or qualitative criteria. It is suggested that, where permissible, cores should be taken so that more sophisticated tests, such as total porosity and electron microscopy, can be carried out to validate the in-situ nondestructive test methods.