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This contribution presents an alternative method for the processing of concrete. The stress needed for comminution is generated by high-performance sonic impulses. The separation of the components of concrete aggregates and cement paste can be necessary due to different reasons. On the one hand, an effective but sensitive separation is required as prerequisite of reliable analysis of both cement paste and aggregate in hardened concrete. Then, the reasons of the damages of building materials can be detected better. On the other hand, methods of crushing that allow to remove clean cement paste free aggregates are also desirable for the recycling of concrete debris. The results show that it is possible to use shock waves as a tool for the processing of concrete. By variations of the electrical parameters, the converted energy can be varied widely. The number of impulses and the voltage are the main influences on the particle size reduction and the quality of crushing product. For the examined concrete, with strength of 25 N/mm2, an optimum treatment is possible at an energy input in the range of 44–80 J/g. About 50% of the grains greater than 2 mm are free of cement paste. |
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