Correlation of Ultrasound Pulse Velocity with Pozzolanic Activity and Mechanical Properties in Lime-Calcined Clay Mortars

The relationship between ultrasound pulse velocity (UPV) with pozzolanic activity of lime mortars produced with clays calcined at different temperatures were examined. Three different types of clay samples were calcined at 550, 650, 750 and 850°C. All the calcined clays were ground in proper granulometric sizes and with them, a series of 12 batches of lime mortars were mixed. From three per mix, a total of 36 samples were prepared in accordance with TS 25 standard. Two extra batches of mortars were prepared for comparison purposes; pure lime mortar and a pozzolanic lime mortar mixed with rock powder. All the samples were cured in accordance with ASTM C593-95 standard. There is a close and good relationship between the UPV with pozzolanic activity and mechanical properties of lime mortars produced with clays calcined at different temperatures. Hence, pozzolanic activity can be predicted also by non-destructive methods.