RESEARCH ON CHARACTERISTICS AND RELIABILITY OF VARIOUS METHODS FOR MEASURING THICKNESS OF POLYURETHANE WATERPROOFING MEMBRANE

Abstract

Field measurements of thickness of a polyurethane membrane applied on an actual building by four kinds ofmeasuringmethods such as ultrasonic wave measuring, eddy current measuring, needle penetration and direct measuring of cut-out specimens were first carried out, and the advantages and disadvantages of each method were discussed. As for the technique to collect a cut-out piece from a membrane, a new one of capable of reliably collecting using a punch of 10mm in diameter was developed. The specimens of various compositions and wide rage of thickness were prepared and their thickness measured carefully in a laboratory, and the accuracy of thickness by each measuring method was discussed. Finally the suitable combination between various thickness measuring methods and polyurethane membranes of different thicknesses and compositions was proposed.