Title: Influence of Latex Paint Compositions on Concrete Against Chloride Penetration
Author(s): K. L. Uemoto and V. Agopyan
Publication: Symposium Paper
Appears on pages(s): 79-94
Keywords: deterioration; durability; latex; pigment
Chloride ion is the main deterioration factor of concrete structures, mainly for external surfaces. These surfaces can be protected by paints, which may reduce the penetration of aggressive agents from external sources. A wide range of organic polymers are used as coatings for concrete and for each generic group a large number of formulations with different permeability against aggressive agents is possible. In order to understand the influence of paint composition on chloride ion penetration, acrylic latex paints with different pigment/binder ratios were studied. The objective of the study was also to evaluate the chloride penetration according to two methodologies. One, based on ASTM Cl202 “Electrical indication of concrete’s ability to resist chloride ion penetration” and the other, according to the previous method with modifications. The ASTM method allows us to obtain results in few hours; however, there are some controversies about this test and on the acceleration rate phenomenon. The tests were carried on applying paints on two different concrete substrates. The results not only show there is a correlation between paint composition and chloride penetration but also that the acrylic latex paints provide an effective barrier to this ion.