Both Ordinary Portland Cement (OPC) and Portland Pozzolana Cement (PPC) can be used for making fly ash bricks. However, PPC is often preferred due to its pozzolanic properties which make the bricks more durable and resistant to moisture.
The typical mix proportion for fly ash bricks manufacturing with cement includes 50-60% Fly Ash, 30-40% River Sand or Stone Dust, and 8-12% Cement
It’s also noteworthy that fly ash bricks can be considered as “self-cementing” since class C fly ash contains a significant amount of calcium oxide. In some processes, the composition of fly ash bricks is 60% fly ash, 30% sand, and 10% Portland cement
However, the choice of cement will depend on various factors including availability, cost, specific project requirements, and your personal preference.