ABSTRACT
The diffusion resistance of a barrier coating to water, air, chloride ions and water vapour is an important property directly related to its performance characteristics in practice. However, it is not sufficient to test the coating in its natural state: when applied to concrete surfaces, the coating will be subjected to tensile forces and stretched over crack openings due to various movements and expansive forces occurring within the concrete. It is therefore important to carry out the tests in both these stress states. In the tests reported here, the AW coating (1.0mm thick, primer+base +top coating) was tested (a) in initial unstretched condition, and (b) stretched to 100% elongation.
