NDE of Concrete Strength and Elasticity Modulus Based on Jerk Measurement

The quality assessment of concrete material for new or existing buildings is critical to civil and structural engineers. In this scope, the development of nondestructive testing methods (NDT) has received significant attention and becomes essential for enhancing the on-site assessment of concrete performance. The Schmidt hammer (SH) test is one of the most widely used NDT for quantifying concrete strength. However, the reliability of this test and its accuracy are questioned by many researchers. In this study, the measurement quality of SH has been improved by attaching a developed cantilever-based jerk sensor to the SH mass. The theoretical model of the proposed measurement technique has been formulated and discussed. The experimental approach, jerk sensor design, SH body modification, electronic reading unit, testing, and construction of the calibration curves have been presented. Experimental results revealed that the accuracy of the developed SH has increased by 13% for concrete strength measurement, and the correlation coefficient of the strength calibration curve is 0.94. At the same time, the calibration curve of the concrete elasticity modulus showed a 0.93 correlation coefficient with 92% measurement accuracy. Analytical and experimental results have confirmed the applicability of the modified Schmidt hammer since it is reliable and more accurate compared to the traditional Schmidt Hammer.