Evaluation on effect of spraying ecological concrete on vegetation restoration of highway masonry slope

Traditional highway slopes are typically stabilized using masonry structures such as frame beams, arch grids, and shotcrete. However, over time, exposure to weathering from rainfall, sunlight, and temperature fluctuations can lead to deformation, sliding, and even structural failure which often result in cracking, damage, rockfalls, or collapses. Additionally, the impermeable nature of masonry structures restricts the exchange of water and air between the slope soil and the surrounding environment, creating significant challenges for vegetation restoration on highway slopes. At the entrance of a tunnel on the Yunmao Expressway, a field experiment utilizing sprayed ecological concrete for slope stability and vegetation restoration was conducted. The physical and chemical properties of the slope, along with plant communities and slope stability, were monitored and analyzed over 1080 days. The results indicate that ecological concrete vegetation restoration technology significantly enhances the vegetation performance of masonry slopes. It possesses superior physical properties and chemical properties to soil underlying masonry slopes, providing support for seed germination and long-term plant growth. This technology successfully reconstructs a multi-layered “grass-shrub-flower” vegetation structure on the masonry slopes. Furthermore, it improves slope stability, enhancing the erosion resistance and preventing weathering and peeling of the masonry slope. An evaluation system was established to assess vegetation restoration effectiveness. The system is composed of four main criteria layers: physical properties of ecological concrete, chemical properties of ecological concrete, plant communities, and slope stability comprising a total of 16 indicator layers, was established based on the Fuzzy Analytic Hierarchy Process (F-AHP), The evaluation results indicate the vegetation restoration effectiveness as “excellent”, which is consistent with the field conditions. The findings demonstrate that ecological concrete technology effectively addresses the challenges of vegetation restoration and slope stability on masonry slopes, offering significant potential applications.