Damage assessment of semi-precast slabs using impact-echo method

Semi-precast slabs are widely used in precast concrete constructions in China nowadays.However the construction quality of them are often hard to control, and the constructoion quality of the upper in-situ concrete of them is difficult to be guaranteed, as a result, how to detect the construction defects correctly and timely become more and more important. In this paper a traditional method Impact-Echo (IE) method is used to detect the flaws between the precast concrete and the upper in-situ concrete of the semi-precast slabs. Firstly one experimental slabs with many designed flaws was constructed, and than IE method was used to detect these flaws, fially the detected results were analysed to evaluate the proposed method. The results were processed using a mapping strategy, which indicated suspicious points where core extraction was undertaken. All cores taken from points derived from IE method results were found to have flaws providing evidence. The experimental results show that IE method may be a suitable tool to assess the construction quality of Semi-precast slabs