A Microcontroller-Based Instrument for Measuring P-Wave Speed in Impact-Echo Testing of Concrete

The objective of this paper is to describe a microcontroller-based instrument for measuring P-wave speed in impact-echo test of concrete. This measurement is based on measuring the travel time of the P-wave (Deltat) between two transducers at known distance apart. The present study developed an instrument to record the Deltat using interrupt-on-change feature of microcontroller and calculate the P-wave speed. Laboratory studies were carried out on 20 cm concrete slab and obtained Deltat=73.51 s and C_P=4082.6 m/s. The simple proposed instrument obtained an accurate result compared to the measurement using B&K general purpose data acquisition. For the practical, this instrument is an easy-operated one, light in weight and does not need another data acquisition, portable computer and software program