The investigation of the effect of different cement type and pozzolan fineness on pozzolanic activity in mortars with pumice powder replacement

In study, pumice stone obtained from Erzurum province Pasinler district Demirdöven region was ground in 3 different fineness values, and two species (CEM II/B-LL 32.5 R and CEM II /A-M (P-LL) 42, 5 R) has been replaced with cement at rates of 5%, 10%, 20% and 30%. The study was carried out on standard mortar samples and a total of 26 different mortar groups were produced. At the end of the standard water curing periods, the compressive strength values and pozzolanic activity indexes of the samples at 7, 28, 56 and 90 days of age were determined. Interpreted in accordance with the criteria specified in TS 25 and ASTM C618 standards. In addition, the effects of pumice powder fineness on consistency and heat of hydration were investigated. As a result of the study, the specific surface areas of the ground pumice powder were determined as 4378, 4919 and 6.879 cm2/g. The highest pozzolanic activity indices were determined in the sample groups with pumice powder additive with a 5% replacement rate, the specific surface area of which was determined as 6.879 cm2/g in CEM II /A-M (P-LL) 42.5 R type cement, in the range of 104-121%. The use of pumice powder in the sample production of mortar with additives; It has been seen that it reduces the workability, reduces the heat of hydration, and increases the compressive strength and pozzolanic activity index significantly depending on the fineness of the cement used, the fineness of the pumice powder and the substitution rate.