Sources and uses of Pozzolana


According to the source of availability pozzolana is classified as natural pozzolana and artificial or synthetic pozzolana. The word pozzolana is derived from volcanic ash used by Romans in Italy, at Pozzuoli which was first identified as natural pozzolana. Most of the traditional natural pozzolana belongs to the group of volcanic ashes, slate and shales, diatomaceous earth etc. that were being used since the innovation of Portland cement. Besides the natural pozzolana lot of artificial pozzolana are now produced as by product in industries. Among the artificial pozzolana fly ash, burnt clay, blast furnace slag are most commonly used for manufacture of composite cement.
Recent investigations on granite rock indicate very good pozzalanic behaviour. On the other hand granitic rocks are abundant in the nature. It may contribute a new direction for economical production of pozzolana.         
Pozzolana is extensively used as an addition to Portland cement in countries such as Italy, Germany, Turkey, China, Greece, India and Bangladesh. Compared to industrial by-product, natural pozzolanas are characterized by larger ranges in composition and a larger variability in physical properties. The application of Pozzolana Portland Cement (PPC) is mainly controlled by the local availability of suitable deposits and the competition with the accessible industrial by-product.


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