Factors Affecting Sealer Performance on Concrete

By C. Jim Reader, Gary Johnson

It is often assumed that solvent-based  sealers give better performance than water-based formulations on concrete because the solvent-based sealers are thought to better penetrate into the concrete matrix. In practice, it can be difficult to measure actual penetration of a sealer into concrete, as dyes and colorants used to highlight the sealer may show different migration properties than the polymeric binder.

Confocal Raman spectroscopy mapping has been used to map the depth of penetration of solvent-based, 100% solids, and water-based sealers that employ acrylic and epoxy binders. This mapping shows that neither solvent-based nor water-based formulations showed any significant penetration into the concrete substrate beyond the first few microns of the open surface. A study has also been carried out using a model waterborne acrylic sealer formulation to determine whether additives might influence the penetration of the sealer into the concrete or other factors that could affect the performance of the waterborne coating.

This work has shown that the addition of anti-foaming, coalescing surfactants can improve the protective properties of the coating by improving air release and increasing film network formation at the concrete surface.