Exposed to the atmosphere, calcium hydroxide reacts with carbon dioxide to form calcium carbonate deposits which remain apparent as unsightly, whitish stains. Too often, efflorescence shows up to severely dampen the aesthetic appeal of otherwise successful masonry and composite projects. Most common and problematic in masonry construction and architectural precast products, efflorescence is a persistent problem which has brought about a situation where masonry and precast design flexibility has been unnecessarily limited. Two forms of Efflorescence have been identified - Primary and Secondary . They are distinguished by the point in time at which they occur in relation to the curing process.
Primary efflorescence occurs during the curing process.
These newly formed compounds will contribute cementitious strength and enhanced durability properties to the system in place of the otherwise weak and soluble calcium hydroxide. Unlike other commercially available pozzolanic materials, PowerPozz HRM is a quality-controlled, manufactured material. It is not a byproduct of an unrelated industrial process. Care must be taken to follow good curing practices that will minimize evaporation during curing. The use of High Reactivity Metakaolin works to the root of the efflorescence problem by eliminating the calcium hydroxide from the system.