Effect of Coatings on Concrete Resistance to Physical Salt Attack

摘要

In this study, different types of surface coatings were applied to concrete to assess their suitability for resisting physical salt attack (PSA). Concretes with different water-binder ratios (w/b) were tested and severe PSA conditions were implemented, using sodium sulfate, to obtain conclusive trends on the performance of coatings. Visual assessment and mass loss of concrete specimens were used as physical indicators to quantify the damage, while mineralogical and microstructural studies were conducted to elucidate the damage mechanisms. Epoxy, ethyl silicate, and acrylic emulsion coatings were found successful at protecting concrete from PSA regardless of the quality of the substrate concrete, while other coatings tested were highly dependent on the concrete quality. Coatings that permit a high rate of absorption and/or desorption (evaporation) led to more severe PSA damage compared with coatings with low absorption/desorption.