18 c Correlation of Schmidt Hammer Rebound Numbers with Ultrasonic Pulse Velocity and Slake Durability Index of Dolomitic Limestone of Khyber, North Pakistan

Abstract

The ultrasonic pulse velocity and slake durability index are the indirect techniques used widely for rock strength determination. Various experimental studies like slake durability apparatus, ultrasonic pulse velocity and Schmidt hammer have been conducted on dolomitic limestone. The correlation of Schmidt hammer rebound number has been developed with these properties. The uniaxial compressive strength has been determined using the correlated rebound number. Statistical analyses were conducted and the most suitable models were recommended. The linear model was suited in correlation of Schmidt hammer and durability while exponential model appeared best fit with pulse velocity. Most of the tested samples show pulse velocity in the range of 1800-3800m/s. The mean value of pulse velocity was 2751 m/s while the rebound hammer value was 45. Using the correlations from literature the compressive strength calculated by rebound hammer and pulse velocity was 146MPa and 66MPa respectively.