Estimation of Unconfined Uniaxial Compressive Strength Using Schmidt Hardness and Ultrasonic Pulse Velocity

Abstract

Unconfined Compressive Strength (UCS) of the rocks plays a significant role in geotechnical and rock engineering projects. Due to difficulties UCS estimation is done using indirect methods such as Schmidt Rebound Hammer (RN) and Ultrasonic Pulse Velocity (UPV) tests that are quick and inexpensive tests. This study was performed to provide data consisting of correlations between RN versus UPV and UCS for rock materials. RN and UCS and UPV tests were carried out on 66 rock specimens from 6 different rock samples in the laboratory. Linear models were used for the relations between RN and UCS and UPV because R 2 values of linear model is more suitable than non-linear models. The equations proposed in this study can be used easily for the areas formed of sandstone, limestone, arkoses, and granite to pre-estimate the UCS values of the rocks.

Statistical Analyses and Geotechnical Evaluation of Nubia Sandstone, Golden Triangle Area, Egypt

“…Therefore, indirect non-destructive tests are frequently employed to obtain empirical equations to estimate the mechanical properties of rocks (Minaeian & Ahangari, 2013). Ultrasonic P-wave velocity (UPV) test for example is one of the essential non-destructive tests, which is employed to investigate some properties of rocks, such as degree of rock weathering (Schmidt, 1951), tensile strength (Hosseini & Shirin, 2015), UCS (Kurtulus et al, 2018), elastic properties (Abdullah et al, 2019), slake durability index (Hosseini, 2016), and the physical properties of rocks (Kurtuluş et al, 2016).…”

Nondestructive Determination of Strength of Concrete Incorporating Industrial Wastes as Partial Replacement for Fine Aggregate

“…Studies have proven that nondestructive testing is important in most cases where drilling of the concrete core is not advisable, because of the weakening of concrete structure due to drilling [19]. The drilling process when obtaining concrete core samples from an existing structural member will cause a reduction in the load-bearing capacity of the concrete, thus affecting the integrity of the concrete structure and possibly causing a structural defect in the future [20].…”

“…Nevertheless, it is important to understand that several factors should be in place when evaluating concrete structures using the Schmidt rebound hammer test. Factors such as the surface irregularity of sample, space between impact, surface hardness, age of the concrete sample, moisture of sample, presence of void and calibration of Schmidt rebound hammer [3,13,20,21] are used to evaluate the relationship between nondestructive (Schmidt rebound hammer test) and destructive test on compressive strength of concrete. It was reported that the correlation coefficient showed an excellent relationship between rebound number and compressive strength.…”