We are offering fly ash brick etc. We offer fly ash bricks are building materials, specifically masonry units, containing class c fly ash and water. Compressed at 4,000 psi and cured for 24 hours in a 150 â°f (66 â°c) steam bath , then toughened with an air entrainment agent, the bricks last for more than 100 freeze-thaw cycles. Owing to the high concentration of calcium oxide in class c fly ash, the brick can be described as "self-cementing". The manufacturing method is said to save energy, reduce mercury pollution, and costs 20% less than traditional clay brick manufacturing.