Assessing the uniaxial compressive strength and tangent Young's modulus of basalt rock using the Leeb rebound hardness test

Basalt was used as an ornamental stone in many historic and ancient cities in Jordan. Measuring the uniaxial compressive strength (UCS) and the tangent Young's modulus (E-t) in the laboratory requires premium quality specimens with special core dimensions. This research focuses on correlations both UCS and E-t with Leeb Rebound Hardness Test (LRH). In the laboratory, UCS, E-t, and LRH were performed on 90 core samples extracted from 30 different rock boulders collected from the neighboring area of Umm al-Jimal, a historic city in northeastern Jordan. A strong power correlation with (R-2 = 0.888, RMSE = 5.464) was found between non-destructive LRH value and UCS. On the other hand, a moderately strong linear regression with (R-2 = 0.792, RMSE = 4.661) was found between E-t and LRH. In conclusion, non-destructive LRHs can be used as indictors for evaluating both UCS and E-t during the restoration of the historic city Umm al-Jimal and the rehabilitation of other existing structures.