A product that is obtained as mineral additives (pozzolan) at a rate defined in its standards (maximum 55%.A large
constituent percentage of this type of cement is composed of tras which is the most important natural puzzolana.
Because tras consists of high amount of reactive SiO2 and Al2O3.
It has binding characteristics.So,it could be included
as large amount.Tras makes a positive effect of released heat reduction on mortar setting.