The stiffness coefficients of different types of limestone were determined using the through thickness ultrasonic test and measurements of size and weight, and the results obtained verified using aluminium specimens of known mechanical properties. The values of density and stiffness coefficients obtained for the various types of limestone were consistent with their different formation processes. The stiffness coefficients for each specimen were different, exhibited directional properties and were significantly lower in one of the three mutually orthogonal directions in which tests were conducted, a clear confirmation of the heterogeneous and layered nature of limestone. Clearly, therefore, while the through thickness ultrasonic test easily yielded through thickness values of stiffness coefficient, complete characterisation of limestone, would require the use of more complex ultrasonic testing equipment and methods.
(Journal of Civil Engineering, JKUAT: 2002 8: 99-110)