Experimental Study of Detection of Void Between Concrete Slab and Soil Based on Impulse Response Method

Abstract:

This paper focused on the application of the impulse response method to detect void under concrete slab. First, the perniciousness of void under concrete slab was introduced, and the limitations of current detection methods were analyzed. Then, the basic principle and the advantages of the impulse response method were described. After that, model tests on detection of void under concrete slab by using the impulse response method were performed to demonstrate the feasibility of the method. During the experiment, soil was first filled into a test chamber to make a model ground, and a concrete slab was casted on the ground surface. The concrete slab was knocked by a hammer at a certain point to create stress wave. The dynamic responses of the concrete slab were measured by the sensors located at different places on the concrete slab. The obtained data were processed and analyzed using the impulse response method, and the positions and ranges of the voids under the concrete slab were further identified. The identification results were compared with the actual void situations under the concrete slab. The impulse response method was proved to be feasible and efficient in detecting the void phenomenon under concrete slab, thus providing a new way to detect void and evaluate the effect of repair.