Cement blocks, “Hitech Blocks” are manufactured by using proportionate blend of cement, high quality fly ash and lime . These blocks are made lightweight by adding alumina powder to the slurry made of cement –fly ash-lime – this alumina powder reacts with the slurrypaste and releases hydrogen gas and thus creates millions of tiny air cells leading to a strong cellular structure . A cake formed with this process is further strengthened by high pressure steam curing in the autoclave. Stringent quality control is ensured throughout the process