Comparison of liquid dispersions with spray-dried acrylic polymers as modifiers of a cement-based patching material

This study was carried out to compare the performance of dry polymers to the more conventional liquid-based polymers in a general purpose patching mortar. A series of polymer-modified mortars were thus evaluated, comparing two spray-dried redispersible acrylic powders with two water-based polymers: an acrylic dispersion and a styrene-butadiene rubber dispersion. The results of the testing showed that the use of the redispersible powders resulted in mortars with excellent adhesion and strength properties comparable to the liquid product. The mortars modified with these dry polymers also exhibited slightly higher shrinkage than the dispersions. However, combined with their advantages over liquid product, such as ease of shipping and handling, the dry polymers are very suitable for use in the formulation of high-performance patching materials.