Influence of density and porosity on the estimation accuracy of uniaxial compressive strength and elasticity modules from Schmidt rebound number for limestones

In the present study, the effect of density (ρ) and porosity (n) on the accuracy of correlation between uniaxial compressive strength (UCS) and modulus of elasticity (E) with Schmidt rebound hardness (HR) was investigated. For this purpose, 15 different limestones were selected and their petrographical characteristics, physical (ρ, n) and mechanical (UCS, E, HR) properties were determined. In the following, simple and multivariable regression analyses based on the HR, ρ and n for estimating the UCS and E were proposed. The relationships proposed based on the statistical tests have been investigated, which indicates their appropriate accuracy. Comparison of simple and multivariate relationships shows that ρ, n play an important role in increasing the estimation accuracy of UCS and E from HR. Moreover, the results show When HR and ρ be used as the input parameter in the regression analysis, the value of the determination coefficient for estimating the UCS and E are 0.88 and 0.83, respectively. Whereas, if HR and n be used as input parameters, the value of the determination coefficients for estimating the UCS and E are 0.91 and 0.74, respectively.