Bioimprovement of Soils for Highway Applications Using Rolled Erosion Control Products

Highway departments are regularly faced with minimizing the soil erosion from highway construction sites. One of the most effective ways of minimizing soil erosion is to provide ground cover that can intercept raindrops. Although bioimprovement (vegetation) is commonly used, it is difficult to establish on steep slopes and in high flow areas, and to a suitable density to provide adequate ground coverage. As a result, rolled erosion control products (RECPs) are often used to provide immediate ground cover protection for soils, enhance the growth of vegetation, and reinforce vegetation once it is established. The success of RECPs has led to development of a wide variety of different RECPs that can vary significantly in basic properties and performance. Although many studies have been published documenting the successful use of RECPs, limited work has been done to compare the rainsplash erosion performance of different types of vegetated RECPs and their mechanisms in minimizing soil erosion. On the basis of results of more than 200 laboratory rainsplash erosion tests on 13 different types of vegetated RECPs, it was found that the use of vegetated RECPs can significantly reduce soil losses on bare soil slopes by an average of 95% to 100% in comparison with bare soil alone. Vegetation improved the performance of the RECPs alone by an average of 54% and 95%. Care must be taken in the design and selection of RECPs to optimize their performance.