Chemical Treatment of Efflorescence in Clay Bricks During the Manufacturing Process

Efflorescence is a white deposit of salts that are deposited on the faces of buildings constructed using bricks, resulting from the evaporation of water loaded with dissolved salts. The source of these salts is usually from the raw material itself. It is an aesthetic issue as well as affecting the durability of building units. This study aims to treat this phenomenon chemically during the manufacturing process by adding inhibitors. The barium carbonate compound (BaCO3) was used as an inhibitor in proportions ranging from 2–20% added to Al-Nahrawan and Al-Angor clay, respectively. The samples were burned at 950°C. Efflorescence test performed according to ASTM C67-08. Apparent porosity, water absorption, and linear shrinkage tests were performed. The results of the tests showed that the efflorescence rate decreased as the inhibition rate increased, this is because the barium carbonate compound leads to the conversion of water-soluble salts into insoluble salts. The tests showed a slight increase in the percentage of pores and water absorption and an increase in the length of the samples as the barium carbonate percentage increased.