The novel vegetation concrete blocks for embankment protection incorporating the light aggregates recycled by lake-dredged sediments

Abstract

The recycling of lake-dredged sediments (LDS) is an environmental issue of great concern, and its reuse in ecological slope protection is a new endeavor with economic and environmental advantages. However, the feasible process and reasonable parameters of this recycling concept are still unrevealed. In this paper, we presented a guiding framework for recycling lake-dredged sediments into lightweight aggregate for eco-friendly porous vegetation concrete blocks. The laboratory tests show that the LDS from Dongting Lake could be directly sintered the lightweight aggregates under the optimal processing parameters (preheating temperature of 800 °C and time of 5 min, and sintering temperature of 1150 to 1250 °C and time of 8 to 10 min). After that, porous matrix was manufactured using the LDS lightweight aggregates and cement with an optimal mix proportion (w/c of 0.27, lightweight aggregate with a particle size of 1.5 cm and a target porosity of 25%). Moreover, the porous matrix and hexagonal concrete blocks were combined and produced as vegetation concrete blocks, which have shown good performance in the slope protection project of the Dongting Lake embankment. Compared with the traditional embankment blocks, this scheme saves about 38% costs in raw materials and LDS treatment.