Preparation of shale ceramsite vegetative porous concrete and its performance as a planting medium

Vegetative porous concrete (VPC) could effectively reduce the adverse impacts of engineering construction on the environment and adapt to the demands of sustainable development. In this article, shale ceramsite was selected as coarse aggregate and Cynodon dactylon was chosen as an experimental plant. Based on the conditions of two target porosities and four water-cement ratios, the mixture proportions of VPC were designed. Modified soil was made, in which fly ash, compound fertiliser, FeSO4 and vinyl acetate emulsion were mixed in yellow-brown loam. Planting substrate slurry made of modified soil, humus, vermiculite powder according to the proportion of 2:2:1 and the right amount of water. Given two planting structures, planting tests were conducted on the VPC. Results showed under the conditions of target porosity and grain composition, bulk densities of 12 groups of VPC varied between 600 and 800 kg/m(3), compressive strengths of 28 days old were 5 MPa above and pH values varied from 11 to 12 in the porous concrete internal voids. Plant height exceeded 10 cm and plant covered more than 95% at the age of 60 days in both two planting structures. The results are great significance for using VPC to enhance slope landscape and prevent soil erosion, shallow landslides and other geological disasters.