Concrete recycling by pulsed power discharge inside concrete
S. Inoue1, S.Iizasa1, D. Wang2, T.Namihira3, M.Shigeishi1, M.Ohtsu1, H.Akiyama1
1Graduate School of Science and Technology, Kumamoto University
2Priority Organization for Innovation and Excellence, Kumamoto University
3Bioelectrics Research Center, Kumamoto University
Abstract— In Japan, most of concrete scraps wasted have been reused as roadbed materials and the recycling ratio of waste concrete has been kept over 95 % since 2000. However, it is expected that the needs of concrete scraps as roadbed materials decrease, where as the concrete scraps wasted increase due to reconstruction of buildings in the next decade. The fact means that the recycling of waste concrete is urgently to be developed. Therefore, the development of new and advanced recycling technology of waste concrete is of paramount importance in Japan.
In this work, the pulsed power discharge inside concrete scraps immersed in water was used to reproduce the coarse aggregate. The Marx generator was used as the pulsed power source and the point to hemisphere mesh electrode was immersed in water. In the experiments, the pulsed voltages were applied to concrete scraps placed on hemisphere mesh and the reproduced coarse aggregates were evaluated after the repetitive discharge treatment and the concretes which were made by the reproduced coarse aggregates were evaluated. From the results, it is clarified that the repetitive discharge treatment of the concrete scraps produces the recycled coarse aggregate under Japan Industrial Standard (JIS) regulation. Furthermore, the quality of the recycled coarse aggregate was controlled by the consumption energy of the discharge treatment. In addition, the concrete made by the recycled coarse aggregate has enough strength as the construction material.
Keywords— Pulsed power, concrete, aggregate, recycle, discharge, shock wave, marx generator, environment