In order to improve the required quality of concrete structure, it is indispensable to solidly fill all angles and corners of the forms with homogeneous fresh concrete. A novel long and narrow capacitance-based wetting sensor which helps in monitoring the process of concrete placement was developed. A series of laboratory experiments were performed to measure sensor performance. The results presented in this paper show that not only placed height and consolidation status of fresh concrete but also honeycombs occurred on the surface can be detected immediately by using the sensor system.
