The performance and temporal dynamics of vegetation concretes comprising three herbaceous species in soil stabilization and slope protection

Abstract

Vegetation growing concrete (VGC) is a kind of concrete composed of a sand-free porous concrete skeleton and plant-growing substrate, which has a certain strength and is suitable for plant growth. In this study, Lolium perenne, Festuca arundinacea, and Festuca rubra were used to construct VGC. The variation and temporal changes in the effects of these three herbaceous plants on the performance of VGC in terms of soil stabilization and slope protection were assessed herein. Plant growth at different growth stages, rainfall interception by the aboveground parts of the plants, and the erosion resistance and shear strength of the substrates were evaluated concurrently. The growth rate of the stems, leaves, and root systems of the three species of plants decreased over time. Overall, L. perenne had the best growth state, followed by F. rubra and F. arundinacea. The maximum interception amount and the maximum interception rate of the aboveground part of the vegetation increased initially then decreased over time. L. perenne had the highest maximum interception amount and rate, which were 83.5% and 12.7% higher than those of F. arundinacea, respectively, and 32.7% and 7.7% higher than those of F. rubra, respectively. Plant roots enhanced the erosion resistance and shearing strength of VGC. The erosion resistance and shearing strength of VGC increased over time and reached the maximum value at the later stages of plant growth. L. perenne had the highest enhancement effect on erosion resistance and the highest shearing strength, which were 5.9% and 8.3% higher than those of F. rubra, respectively, and 10.7% and 16.4% higher than those of F. arundinacea, respectively. Among the three herbs, L. perenne is the appropriate species for the construction of VGC for slope protection in the mountainous areas of southwest China.