Efflorescence mechanisms of formation and ways to prevent

Mechanisms of Formation and Ways to Prevent

Thomas Aberle, Roger Zurbriggen and Adrian Keller, Nouryon Chemicals AG, Switzerland

The unaesthetic discoloration of cementitious materials by efflorescence is a major issue in the dry mortar industry. The paper describes the phenomena in general with special focus on decorative mortars like renders. The mechanisms and influencing factors of efflorescence are well described in the literature.
Most critical climatic conditions are low temperatures and high humidity. There are many different test procedures to simulate this. A special „double-chamber climate box“ test was developed.
Finally, the authors demonstrate efflorescence test results from renders modified with a newly developed anti-efflorescence product.