Fundamental Principles of Measuring Concrete
This figure shows the waveform of the impact force when hammering the concrete with the CTS-02. The waveform is measured by the built-in sensor and can be divided into two sections. The first section of the waveform up to the peak shows the time the hammer is pushing onto the concrete surface. The maximum displacement of the concrete surface occurs at the peak of the graph when the impact force reaches its maximum value. The second section of the waveform past the peak shows the time when the displacement of the concrete surface comes back to the origin. This rebound process happens through the elastic deformation energy of the concrete pushing back on the hammer. Reviewing the impact waveform in the second section, the mechanical impedance of hammer contact as the plasticity index of the concrete is measured and the strength of the concrete can be estimated from the impedance value with no damage to the concrete surface. This analysis is patented No. 3691477.