Long-term performance of redispersible powders in mortars

Long-term performance of polymer-modified mortars in outdoor and indoor exposure was examined over 10 years. Three redispersible powders based on different copolymers were used. Over the 10-year period the vinylacetate-ethylene (VAE) copolymer market standard as well as styrene-acrylics (SA) and an ethylene-vinylchloride-vinyllaurate (terpolymer) gave stable adhesive, flexural and compressive strength. The terpolymer also showed long-term performance in hydrophobicity over a 5-year period in stuccos. According to scanning electron microscopy (SEM), the morphology of the polymers in the mortars does not change over the 10-year period. (C) 2001 Elsevier Science Ltd. All rights reserved.