Ceramsites can be used as water storage materials, but the challenges of low water absorption and short water-retention time are restricted to their application. In this paper, a novel multilayer powder coatings method was used to prepare a structure-designed ceramsite. The results showed that the structure-designed ceramsite can be prepared by a multilayer powder coating method. A ceramsite with large internal and small external pores has superior properties, with a water absorption rate of 51.3% at 24 h and a water-retention time of 56 h at 50 °C and 55% RH. This work not only broadens the new way of solid waste resource utilization but also has great significance in promoting the construction of sponge cities and overcoming the urban heat island effect.
Keywords: multilayer powder coating; porous ceramsite; sponge city; structure design; water retention.